Circuit panel: April 2013

Tuesday, April 30, 2013

AC 230V Led Circuit Diagram by DIAC

Tthis is a very simple LED flasher circuit diagram that is powered from AC 230V mains. This Flasher can be used as a power indicator for the AC 230V mains supply. This circuit is made with few numbers of parts namely, a LED, two Resistors, one Capacitor, one Diode and one DIAC. The DIAC act the main role to flashing the LED. DIAC is a bidirectional device. It conducts current only after its breakover voltage has been reached its threshold. Most DIACs breakover voltage is around 30 V.

230V Mains Power Indicator LED Flasher Circuit Diagram

When mains is connect to the circuit, the Capacitor(C1) starts charging through Diode(D1)&Registor(R1). When the voltage on the capacitor reached the DIAC’s threshold voltage, the DIAC get turn on. And LED gets Lights(flash). At the same time Capacitor(C1) goes discharges and breakover voltage of DIAC also decrease and LED turns OFF. The on off time of the LED depends on the value of Capacitor(C1) and Resistor(R1).

Note that the flashing time of the LED shown in the animating figure is not the exact timing of ON/OFF.

Copyright : CircuitsTune.com

Car Interior Lights Delay

Most cars do not have delayed interior lights. The circuit presented can put this right. It switches the interior lights of a car on and off gradually. This makes it a lot easier, for instance, to find the ignition keyhole when the lights have gone off after the car door has been closed. Since the circuit must be operated by the door switch, a slight intervention in the wiring of this switch is unavoidable. When the car door is opened, the door switch closes the lights circuit to earth. When the door is closed (and the switch is open), transistor T1, whose base is linked to the switch, cuts off T2, so that the interior light remains off. When the switch closes (when the door is opened), the base of T1 is at earth level and the transistor is off.

Circuit diagram:

Capacitor C1 is charged fairly rapidly via R3 and D1, whereupon T2 comes on so that the interior light is switched on. When the door is closed again, T1 conducts and stops the charging of C1. However, the capacitor is discharged fairly slowly via R5, so that T2 is not turned off immediately. This ensures that the interior light remains on for a little while and then goes out slowly. The time delays may be varied quite substantially by altering the values of R3, R5, and C1. Circuit IC2 may be one of many types of n-channel power MOSFET, but it should be able to handle drain-source voltages greater than 50 V. In the proto-type, a BUZ74 is used which can handle D-S voltages of up to 500 V.

Saturday, April 13, 2013

FINDING THE BASE and determining NPN or PNP

FINDING THE BASE and determining NPN or PNP
Get an unknown transistor and test it with a multimeter set to "x10"
Try the 6 combinations and when you have the black probe on a pin and the red probe touches the other pins and the meter swings nearly full scale, you have an NPN transistor. The black probe is BASE
If the red probe touches a pin and the black probe produces a swing on the other two pins, you have a PNP transistor. The red probe is BASE
If the needle swings FULL SCALE or if it swings for more than 2 readings, the transistor is FAULTY.

Phono Preamplifier Circuit

Simple circuitry, Passive high-frequency equalization

n recent years, following CDs introduction, vinyl recordings are almost disappeared. Nevertheless, a phono preamplifier is still useful for listening old vinyl discs from a well preserved collection. This simple but efficient circuit devised for cheap moving-magnet cartridges, can be used in connection with the audio power amplifiers shown in these web pages, featuring low noise, good RIAA frequency response curve, low distortion and good high frequency transients behavior due to passive equalization in the 1 to 20 KHz range.

Phono Preamplifier Circuit diagram:

Phono Preamplifier Circuit diagram

Parts:
R1 = 47K
R2 = 100R
R2 = 6.8K
R4 = 68K
R5 = 2.7K-1/2W
R6 = 2.7K-1/2W
R7 = 2.2K
R8 = 39K
C1 = 100uF-25V
C2 = 100uF-25V
C3 = 100uF-25V
C4 = 47nF-63V
C5 = 47nF-63V
D1 = BZX79C18
D2 = BZX79C18
Q1 = BC337
Q2 = BC327
J1 = RCA Jack
IC1 = LM833, Opamp

Notes:

R2, R3, R4, R7, R8, C4 & C5 should be low tolerance types.
Schematic shows left channel and power supply.
For stereo operation R1, R2, R3, R4, R7, R8; J1; C1, C4 & C5 must be doubled.
Numbers in parentheses show IC1 right channe

Source : http://www.ecircuitslab.com/2011/06/phono-preamplifier-circuit.html

Voltage to current converter with floating load

The current in the feedback loop depends on the voltage and Ri.
This applications where we need to pass a constant current through a
load and hold it constant despite any changes in load resistance or load
voltage. When the load does not have to be grounded, we simply place
the load in the feedback loop and control both input and load current from this circuit.

This circuit shown in figure voltage to current converter
with floating load. The voltage to current converter can be used in
such applications as low voltage dc and a voltmeters, diode match
finders light emitting diodes (LEDS) and zener diode tester.

This circuit diagram Figure shows a voltage to current converter in which load resistor R_L is
floating (not connected to ground). The input voltage is applied to the
no inverting input terminal and the feedback voltage cross R₁ drives the inverting input terminal. This circuit is also called a current series negative feedback amplifier because the feedback voltage across R₁ (applied to the inverting terminal) depends on the output current i₀ and is in series with the input difference voltage v_id.

Outdoor LED Solar Lights Circuit Schematic

This Outdoor LED Solar Garden Lights venture is a passion circuit of an computerized garden mild the use of a LDR and 6V/5W solar panel. During day time, the internal rechargeable 6 Volt SLA battery receives charging current from the linked sun panel thru polarity safety diode D9 and current restricting resistor R10. If ambient light is commonplace, transistor T1 is reverse biased through IC1 (LM555). Here IC1 is wired as a medium current inverting line forcer, changeed by using an encapsulated light detector (10mm LDR). Multi-turn trimpot P1 sets the detection sensitivity. When ambient gentle dims, transistor T1 turns on to force the white LED string (D1-D8). Now this lamp load on the output of T1 energizes. Resistors R1-R8 limits the running current of the LEDs. When the ambient mild level restores, circuit returns to its idle state and light(s) changeed off by way of the circuit.

Circuit diagram:

$\"Outdoor$

Outdoor Garden Solar Lights Circuit Diagram

Assemble the Outdoor Solar Lights circuit on a basic function PCB and enclose the entire meeting in a transparent plastic box. Drill appropriate gaps on the highest of the enclosure to mount the mini sun panel (SP1) and the solarshine sensor (LDR), and in front for fitting power switch (S1) and the sensitivity controller (P1). Fix the battery within the cabinet the use of a double-sided glue tape/pad. Finally, the LDR will have to no longer be mounted to receive direct sunlight. It must be established on the prime of the enclosure, pointing to the sky say southwards. This circuit could be very simple. So and skilled pastimeists can alter/modify the entire circuit as per their very own ideas with none problem (Just are trying a 6V relay with T1 to force extra number of LED strings).

http://www.ecircuitslab.com/2011/10/outdoor-led-solar-lights-circuit.html

Intelligent Presence Simulator

However effective a home alarm gadget may be, it’s always better if it never goes off, and one of the most straightforward methods to ensure this is to make doable burglars think the premises are occupied. Indeed, until you personal outdated grasps or objects of great worth more probably to attract ‘professional’ burglars, it has to be stated that the majority of burglaries are dedicated by way of ‘petty’ steals who're going to be taking a look greater than the rest for simplicity and can want to interrupt into houses whose occupants are away.

Rather than simply now not occurring holiday – which is also one technique to the problem (!) – we’re going to signify building this sensible presence simulator which ought to position attainable burglars off, although your house is subjected to shut scrutiny. Like all its counterparts, the proposed circuit turns a number of milds on and off when the ambient light falls, however whereas many instruments are content to generate fastened timings, this one works using randomly variable lengths.

Circuit diagram:

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Intelligent Presence Simulator Circuit Diagram

So whereas different softwares are very quickly caught out just with the support of day-to-day commentary (often from a car) because of their too-perfect regularity, this one is way more credible because of the truth that its running instances are irregular. The circuit could be very easy, as we have now employed a microcontroller – a ‘little’ 12C508 from Microchip, which is greater than sufficient for this type ofn utility. It is primarys powered and makes use of rudimentary voltage regulation by using a zener diode.

A relay is used to keep watch over the gentle(s); though this is less based than a triac solution, it does avoid any interference from the primarys attaining the microcontroller, as an instance, all through thunderstorms. We mustn’t disregard this challenge must work very reliably throughout our absence, no matter happens. The ambient gentle degree is measured by a standard LDR (light established resistor), and the gentleing swaping threshold is regulateable by the use of P1 to suit the traits and placeing of the LDR.

Note that enter GP4 of the PIC12C508 shouldn't be analogue, however its good judgment switching threshold could be very suitable for this kind of use. The LED connected to GP1 point outs the circuit’s operating mode, selected by using flooring or no longer of GP2 or GP3 by implys of override swap S1. So there are three conceivable states: permanently off, completely on, and computerized mode, which is the one typically used. Given the software softwaremed into the 12C508 (‘firmware’) and the need to generate very long prolongs with the intention to arrive at lights instances or an hour or extra, it has been vital to make the MCU operate at a vastly scale backd clock frequency.

PCB Layout:

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PCB Layout Of Intelligent Presence Simulator

In that case, a crystal-controlled clock is not appropriate, so the R-C network R5/C3 is used instead. For sure, this kind of clock source is less stable than a crystal, however then in an application like this, that may smartly be what we’re after as a degree of randomness is a design target as an alternative of a drawback. Our recommended PCB shown here takes all the elements for this project apart from after all for S1, S2, and the LDR, so as to need to be positioned on the entrance panel of the case with a objective to sense the ambient mild intensity.

The PCB has been designed for a Finder relay capable of swaping 10 A, which must show ample for lighting your home, except you reside in a replica of the Palace of Versailles. The software to be loaded into the 12C508 is available without cost obtain from the Elektor site as file number 080231-11.zip or from the author’s own web site: www.tavernier-c.com. On completion of the solder work the circuit will have to work instantly and can be checked via swaping to manual mode.

The relay should be launched within the ‘off’ position and energized in the ‘on’ position. Then all that is still is to regulate the day/night threshold via altering potentiometer P1. To do that, which you may either use a selection of patience, or else use a voltmeter – digital or analogue, but the latter will want to be digital as a manner to be high impedance – linked between GP4 and floor. When the sunshine degree below which you need the milding to be allowed to come on is reached, alter P1 to read approximately 1.4 V on the voltmeter.

If this price cannot be executed, because of the characteristics of your LDR, scale back or elevate R8 if necessary to achieve it (LDRs are identified to have quite large manufacturing tolerances). Equipped with this cheaper accent, your personal home of course hasn’t grow to be an impregnable fortress, but as a minimum it ought to seem less horny to burglars than houses which are plunged into darkness for lengthy intervals of time, especially in the center of summer season. (www.tavernier-c.com)

COMPONENTS LIST Resistors
R1 = 1k 500mW
R2 = 4k7
R3 = 560R
R4,R6 = 10k
R5 = 7k5
R 7 = LDR
R8 = 470k to 1 M
P1 = 470k potentiometer
Capacitors
C1 = 470µF 25V
C2 = 10µF 25V
C3 = 1nF5
C4 = 10nF
Semiconductors
D1,D2 = 1N4004
D3 = diode zener 4V7 400 mW
LED1 = LED, purple
D4 = 1N4148
T1 = BC547
IC1 = PIC12C508, programmed, see Downloads
Miscellaneous
RE1 = relay, 10A contact
S1 = 1-pole 3-way rotary swap
F1 = fuse one hundred mA
TR1 = Mains transformer 2x9 V, 1.2 -3 VA
4 PCB terminal blocks, 5 mm lead pitch
5 solder pins

www.ecircuitslab.com

Friday, April 12, 2013

Build Intelligent Wire Loop Alarm Circuit With IC

Integrated circuit anti-theft alarm system, wire or different lack of a easy circuit. When the shortage of wires or cords lacking. MOSFET, it's working or has input voltage at pin G and for this reason it has a high current floats in the route of the pin D-S that Micro piezo siren was once so loud.

$\"Build$

Part List

R1 100K 1/2W 1% Resistor
R2, R4 10K 1/2W 1% Resistor
R3 1 Meg 1/2W 1% Resistor
C1, C3 0.1uF Ceramic Disc Capacitor
C2 0.01uF Ceramic Disc Capacitor
IC1 4001UBE Quad 2-i/p NOR Gate
Q1 MPSA14 Low Power NPN Transistor
SIREN Micro piezo siren 12V DC 150mA, 110dB @ 1M
LOOP See “Notes”

The loop can be any kind of hookup wire, with a most resistance of about 90K. Using very skinny wire (40AWG, for example) will make an awfully sensitive travel wire, but will shorten the distance it will also be strung due to the high resistance.

The siren can be changed with a relay to power external load

1978 Ford F 150 Lariat Wiring Diagram

1978 Ford F-150 Lariat Wiring Diagram

The Part of 1978 Ford F-150 Lariat Wiring Diagram: direct switch, marker light, battery, headlight, light
switch, high beam, indicator, horn relay, yellow wire, green wire, fusible link, starter relay, ignition coil, park light, distributor, ignition module, noise filter, cluth safety switch, alternator indicator, backup light, widshield wiper switch, washer motor, regulator

ATX Power Switch Substitute

An additional push-button switch is normally required for the ATX Power Switch/Soft Power Switch signal, but you can do without it if you use this simple circuit. It is an artful design, but it has been repeatedly tested. The zener diode is intended to provide protection against excessive voltages and reverse-polarity connection. In the latter case, the resulting short-circuit current (approximately 1A) will exceed the allowable limit and cause the ATX power supply to shut down after around five seconds. It might be possible to use a smaller capacitor; this must be tested experimentally in actual use.

ATX Power Switch Substitute circuit diagram

If the motherboard documentation is poor, you should verify the earth pin using a continuity tester. The resistor is only needed if you want to be able to switch on the PC within ten seconds after switching it off. It discharges the capacitor quickly enough to make this possible. With a 1-kΩ resistor, the time constant is around 0.5 s. Since the capacitor also tends to stabilize the voltage, this circuit could also help in situations in which the ATX power supply switches off unintentionally due to voltage fluctuations on the PWR Supply On line.

Pump Controller For Solar Hot Water System

This circuit optimises the operation of a sun scorching water device. When the water in the sunlight collector is sizzlingter than the storage tank, the pump runs. The circuit contains two LM335Z temperature sensors, a comparator and Mosfet. Sensor 1 connects to the sun collector panel whereas Sensor 2 joins to the new water panel. Each sensor includes a trimpot to allow regulatement of the output stage. In practice, VR1 and VR2 are adjusted in order that each Sensor 1 and Sensor 2 have the same output voltage when they are at the same temperature. The Sensor outputs are monitored the utilization of comparator IC1.

When Sensor 1 produces a excessiveer voltage than Sensor 2, because of this that sensor 1 is at the next temperature, pin 1 of IC1 goes excessive and pressures the gate of Mosfet Q1. This in flip forces the pump motor. IC1 embraces hysteresis in order that the output does no longer oscillate when each sensors are producing a an identical voltage. Hysteresis comprises the 1MO feedback resistor between output pin 1 and non-inverting input pin three and the enter 1kO resistor. This offers a nominal 12mV hysteresis in order that voltage at Sensor 1 or Sensor 2 should differ by means of 12mV for modifications in the comparator output to occur.

Circuit diagram:

$\"pump-controller-for-solar-hot$

Pump Controller For Solar Hot Water System

Since the outputs of Sensor 1 and Sensor 2 alternate through about 10mV/°C, lets say that there's a diploma of hysteresis within the comparator. Note that IC1 is a dual comparator with the 2nd unit unused. Its inputs are tied to ground and pin 2 of IC1 respectively. This sets the pin 7 output high. Since the output is an open collector, it is going to be at a high impedance. Mosfet Q1 is rated at 60A and 60V and is appropriate for using inductive hundreds because of its avalanche suppression capability. This clamps any inductively brought about voltages exceeding the voltage score of the Mosfet.

The sensors are adjusted at the beginning with each measuring the identical temperature. This can also be carried out at room temperature; alter the trimpots so that the voltage between floor and the positive terminal learns the same for each sensors. If you wish, the sensors will also be set to 10mV/°C trade with the output said the Kelvin scale which is 273K at 0°C. So at 25°C, the sensor output must be set to (273 + 25 = 298) x 10mV or 2.98V.

Note:

The sensors will produce fallacious outputs if their leads are exposed to moisture they usually must be protected with some impartial remedy silicone sealant. The sensors may additionally be mounted by way of clamping them right away to the outside surface of the sun collector and on an uninsulated part of the storage tank. The thermostat housing is usually a excellent position on the storage tank.

http://www.ecircuitslab.com

25 Metres Range Short Wave AM Transmitter

Here the short wave AM Transmitter circuit design diagram. The circuit is quite simple and easy to build since it applies only a few electronic components. The primary feature of this transmitter is that it really is absolutely free from the LC (inductor, capacitor) tuned circuit and runs using a fixed frequency of 12 MHz that is very stable. An LC based tuned circuit is inherently unstable because of drift of resonant frequency due to temperature and humidity variations.

25 Metres Range, Short Wave AM Transmitter Circuit diagram :

Resistors R1 and R2 are utilized for DC biasing of transistor T1. The capacitor C1 gives coupling in between the condenser microphone and the base of transistor T1. In the same way, resistors R3, R4 and R5 give DC biasing to transistor T2.

The oscillator segment is a combination of transistor T2, crystal XTAL, capacitor C2, C3 and resistors R3, R4 and R5. The crystal is excited by a portion of energy from the collector of transistor T2 via the feedback capacitor C2. The crystal vibrates at its essential frequency and the oscillations happening because of the crystal are placed to the base of transistor T2 across resistor R4. Using this method, continuous undamped oscillations are acquired. Any crystal having the frequency in short wave range could be substituted in this circuit, even though the operation was tried using a 12 MHz crystal.

The Transistor T1 has 3 capabilities:

The transistor features the DC path for extending +VCC source to transistor T2.
It amplifies the audio signals which is generated by condenser mic.
It injects the audio signal into the high frequency carrier signal for modulation.

The condenser microphone transforms the voice message into the electrical signal that is amplified by transistor T1. This amplified audio signal modulates the carrier frequency produced by transistor T2. The amplitude modulated output is acquired at the collector of transistor T2 and is transmitted by a loop antenna into space in the form of electromagnetic waves. The antenna could be tuned to a specific frequency by fine-tuning the trimmer C5 and also by modifying the length of ferrite rod into the coil.

The transmitted signals could be received on any short wave receiver without having distortion and noise. The range of this transmitter is 25 to 30 metres and may be expanded even more in case the length of the antenna wire is suitably extended together with good matching.

A Discharger for Receiver Battery Packs

You may have read about cycling NiCad batteries. If not, read a little here ( Reds R/C Battery Clinic) for an excellent overview. Overcharging apparently leads to voltage depression, which can be corrected by one or two complete discharges (to 1 to 1.1 volts per cell). On the other hand, over discharging the batteries to a low or zero voltage can damage them, and if the batteries have not been overcharged and have no voltage depression, cycling just uses up regular battery life. I designed and use this discharger occasionally to remove voltage depression and insure battery capacity is still ok for those planes that have no low voltage alarm.

Note that the 100 ohm resistors are 1/2 watt (these are the load resistors), the rest are 1/4 watt. The red LED lights while discharging, buzzer sounds and discharge rate drops to 15-25mA (for the buzzer) when complete. The discharge load is 60mA to 110mA depending on the battery voltage. Since thats about the same current draw as my Hitec receiver and two HS-80s draw while flying handlaunch, I can use discharge time almost directly to indicate flying time. The buzzer uses enough current to keep a 150mA battery down, but when discharging a 600mA battery, the battery recovers quickly when the load is removed--the buzzer/discharger cycles on and off. Threshold voltage of the discharger is set to 4.2 volts. Since the discharger still draws some current when buzzing, try to disconnect the discharger once the alarm sounds--dont leave it going for hours lest the battery be over discharged.

Discharger for Receiver Battery Packs circuit

There are a couple ways you could modify the circuit to work with a 5-cell 6-volt receiver battery pack. The two 1k resistors are a divider network, so one way would be to change the resistors to change the sampling voltage at the comparator. The formula for a divider network is Vout=Vin(R2/(R1+R2)) or R1=R2*((Vin/Vout)-1). Here, R1 is the resistor connected to the positive lead and pin 7 of the comparator, Vin is 5.25 volts (1.05 volts per cell discharge shutoff threshold), and Vout is the reference 2.1 volts (the voltage produced by the LM317T and the 180 and 270 ohm resistors). You can use R2 as the same 1k value that was there before. So R1=1000*((5.25/2.1)-1)=1500=1.5k. So swap the top 1k resistor in the schematic for a 1.5k, and the new shutoff voltage for your device will be 5.25 volts.

To increase the discharge rate, decrease the resistance of the load resistors. You could use four 100 ohm resistors in parallel instead of two, for example, and it would discharge twice as fast. Resistance of a number of resistors in parallel is the value of the resistor devided by the number of the resistors. Here, 100 ohms/ four resistors is 25 ohms. At five volts, current is (5 volts)/(25 ohms)=0.2 ampere or 200mA. Be careful not to decrease resistance too much however--the small signal transistor used in this particular circuit is probably only rated for maximum 500 mA.

Circuit diagram :
Discharger for Receiver Battery Packs circuit 1

Discharger for Receiver Battery Packs circuit 1

Discharger for Receiver Battery Packs1

Parts:
273-074 Miniature Piezo Buzzer, 12v, PC board mount
271-312 1/4 watt 5% carbon film resistors, 500 pieces (Just do it!)
276-1778 LM317T adjustable voltage regulator
276-1712 Quad comparator LM339
276-1622 LED assortment (20 count)
276-2009 NPN Silicon transistor MPS2222A (2N2222)

Custom electronics:

I post this design not because I think this is a brilliant piece of circuit design but because the design works, and it can give you a start on your own experimentation. The idea is to use the power available from the discharging battery to monitor the voltage of the battery, shut off discharging at a preset voltage (here 1.05 volts/cell), and sound an alarm when discharging is complete. To do so means a voltage reference powered by the changing voltage of the battery, here the LM317T and the 180 with 270 ohm resistors. You could just as easily use a LM336 (see the low voltage warning buzzer page) or a zener with resistor, or something else as a reference. Since the reference voltage must be below the ambient battery voltage, a pair of 1k resistors provides the divided test voltage. The LM339 is a four way comparator.

This design uses really three comparators: in addition to the one driving the transistor, a comparator drives the LED and another drives the buzzer. But you could use a single comparator (like the LM311) with the buzzer across the emitter and collector of the transistor, and the LED in series with a 270 ohm resistor across (parallel with) the 100 ohm load resistors. With the transistor conducting, the voltage drop across base and emitter is low, and the buzzer is quiet. The tiny current in a piezo buzzer (7 mA), when the transistor is not conducting, would be divided between the load resistors and the LED, and the LED is dark.
A word about the comparator.

Source : http://www.ecircuitslab.com/2011/06/discharger-for-receiver-battery-packs.html

HANDY 0 12V DC POWER SUPPLY ELECTRONIC DIAGRAM

HANDY 0-12V DC POWER SUPPLY ELECTRONIC DIAGRAM

For heat protection, heat sink is needed for the BD679 transistor. It is because it will be over tempered when works more than 200mA.

FEATURES:
0v to 12 volt output:
- 700mA with M 2155
- 1.4amp with M 2156
- 1A with 16v AC 1.5 amp plug pack

Low Cost Garage Stop Light

A novel use of solar cells makes positioning your car in the garage rather easier than old tyres, a mirror, or a chalk mark.The six solar cells in figure 1 serve as power supply and as proximity sensor. They are commercially available at relative low cost. The voltage developed across potentiometer Pi is mainly dependent on the intensity of the light falling onto the cells. The circuit is only actuated when the main beam of one of the cars headlights shines direct onto the cells from a distance of about 200 mm (8 inches). The distance can be varied somewhat with P,

Low Cost Garage Stop Light Circuit Diagram :

Low Cost Garage Stop Light-Circuit Diagram

Under those conditions, the voltage developed across C1 is about 3 V, which is sufficient to trigger relaxation oscillator Ni. The BC547B is then switched on via buffer N2 so that D3 begins to lfash. Diodes Di and D2 provide an additional in-crease in the threshold of the circuit. The total voltage drop of 1.2 V across them ensures that the potential at pin I of the 4093 is always 1.2 V below the voltage developed by the solar cells. As the trip level of Ni lies at about 50 per cent of the supply voltage, the oscillator will only start when the supply voltage is higher than 2.4 V.

The circuit, including the solar cells, is best constructed on a small veroboard as shown in figure 3, and then fitted in a translucent or transparent manmade fibre case. The case is fitted onto the garage wall in a position where one of the cars headlights shines direct onto it. The LED is fitted onto the same wall, but a little higher so that it is in easy view of the driver of the car. When you drive into the garage, you must, of course, remember to switch on the main beam of your headlights!

Source: http://www.ecircuitslab.com/2012/09/low-cost-garage-stop-light.html

1994 Mitsubishi Montero Electrical Wiring Diagram

1994 Mitsubishi Montero Electrical Wiring Diagram

The Part of 1994 Mitsubishi Montero Electrical Wiring Diagram: junction block, tail light relay,

combination meter, column switch, rear combination light, cruise control, back-up light switch, hazard light switch, fusible link, stop light switch, relay box, turn-signal and hazard flasher unit, park/neutral position switch, front combination light, license light, etc. Features: shows the connection and wiring between each parts.

12V Powered 12V Lead Acid Battery Charger with Indicator

Some of you might wonder why a charger is needed at all, to charge a 12 Volt battery from a 12 Volt source! Well, firstly the "12 Volt" source will typically vary anywhere from 11 Volt to 15 Volt, and then a battery needs a controlled charge current and voltage, which cannot result from connecting it directly to a voltage source. The charger described here is intended for charging small 12 Volt lead acid batteries, such as the gelled or AGM batteries of capacities between about 2 and 10 Ah, using a cars electrical system as power source, regardless of whether the car engine is running or not. I built this charger many years ago, I think I was still in school back then. On request of a reader of my web site, Im publishing it now, despite being a rather crude circuit.

12V Powered 12V Lead Acid Battery Charger with Indicator

12V Powered 12V Lead Acid Battery Charger with Indicator

It works, it is uncritical to build, and uses only easy-to-find parts, so it has something in its favor. The downside is mainly the low efficiency: This charger wastes about as much power as it puts into the battery. The charger consists of two stages: The first is a capacitive voltage doubler, which uses a 555 timer IC driving a pair of transistors connected as emitter followers, which in turn drive the voltage doubler proper. The doubler has power resistors built in, which limit the charging current. The second stage is a voltage regulator, using a 7815 regulator IC. Its output is applied to the battery via a diode, which prevents reverse current and also lowers the voltage a bit.

12V Powered 12V Lead Acid Battery Charger with Indicator

12V Powered 12V Lead Acid Battery Charger with Indicator

The resulting charge voltage is about 14.4V, which is fine for charging a gelled or AGM battery to full charge, but is too high as a trickle charger, so dont leave this charger permanently connected to a battery. If you would like to do just that, then add a second diode in series with D3! There is a LED connected as a charge indicator. It will light when the charge current is higher than about 150mA. The maximum charge current will be roughly 400mA. There is an auxiliary output, that provides about 20V at no load (depending on input voltage), and comes down as the load increases. I included this for charging 12V, 4Ah NiCd packs, which require just a limited current but not a limited voltage for charging.

12V Powered 12V Lead Acid Battery Charger with Indicator

12V Powered 12V Lead Acid Battery Charger with Indicator

Note that if the charge output is short-circuited, the overcurrent protection of U2 will kick in, but the current is still high enough to damage the diodes, if it lasts. So, dont short the output! If instead you short the auxiliary output, the fuse should blow. I built this charger into a little homemade aluminum sheet enclosure, using dead-bug construction style. Not very tidy, but it works. Note the long leads on the power resistors. They are necessary, because with shorter leads the resistors will unsolder themselves, as they get pretty hot! The transistors and the regulator IC are bolted to the case, which serves as heat sink. The transistors dont heat up very much, but the IC does.

Source: Homo Ludens

Simple Pulse train to sinusoid converter

The circuit letsyou convert a serial pulse stream or sinusoidal input to a sinusoidal output at 1/32 the frequency. By varying the frequency of Vrn, you can achieve an output range ofl07:1-from about 100 kH2 to less than 0.01 H2. The output resembles that of a 5-bit d/a converter operating on paralleLdigital data. Counter IC1 generates binary codes that repeatedly scan the range from 00000 to 11111. The output amplifier adds the corresponding XOR gate outputs, Vvv or ground, weighted by the values of input resistors R1 through R4.

The 16 counter codes 00000 to 01111, for instance, pass unchanged to the XOR gate outputs, and cause Vom to step through the half-sinusoidal cycle for maximum amplitude to minimum amplitude. Counter output Q4 becomes high for the next 16 codes, causing the XOR gates to invert the QO through Q3 outputs. As a result, VouT steps through the remaining half cycle from minimum to maximum amplitude. The counter then rolls over and initiates the next cycle. You can change the R1 through R4 values to obtain other VouT waveforms. VDv should be at least 12 V to assure maximum-frequency operation from IC1 to IC2.

Build a Digital Stopwatch 0 60sec

Now Build a Digital Stopwatch 0-60sec By using the same circuit of the Digital Stopwatch 0-99sec , we can add an AND gate, and transform the 0 – 99sec stopwatch to a 0 – 60sec stopwatch.We must find a way to control the RESET function of the BCD counter, which is responsible for the counting of the seconds. As we studied above, the circuit resets when we have 99 to 100, that is 1001 1001 à 0001 0000 0000. To make a transformation successfully we must force the pulse from 59 to 60 0011 1001 à 0100 0000 on the output of the BCD counter.

By placing the AND gate, with its inputs on the Q1 and Q2 of the BCD counter of the decades, we make sure that when the gate closes, the RST input of the BCD counter will be set to logical “1”, which on its turn, will force the circuit to start over. The transformed circuit appears in picture 2.

Simple Video Amplifier

The video amplifier in the diagram is a well-known design. Simple, yet very useful, were it not for the ease with which the transistors can be damaged if the potentiometers (black level and signal amplitude) are in their extreme position. Fortunately, this can be obviated by the addition of two resistors. If in the diagram R3 and R4 were direct connections, as in the original design, and P1 were fully clockwise and P2 fully anticlockwise, such a large base current would flow through T1 that this transistor would give up the ghost.

Video Amplifier Circuit diagram :

Moreover, with the wiper of P2 at earth level, the base current of T2 would be dangerously high. Resistors R3 and R4 are sufficient protection against such mishaps, since they limit the base currents to a level of not more than 5 mA. Shunt capacitor C4 prevents R4 having an adverse effect on the amplification.

Source : http://www.ecircuitslab.com/2011/06/video-amplifier-circuit-diagram.html

Portable Satellite Radio and MP3 Player XM XPMP3H1

Portable Satellite Radio and MP3 Player - XM XPMP3H1

The XMp3i Portable Satellite means of communication combines satellite radio and MP3 capabilities into a single compact package. This efficient device shows comedian celebrity, song title, and channel in rank on a hefty color exhibit. The device lets you browse and explore other songs and artists lacking leaving your current channel. join up the XMp3i with an XM subscription design to facilitate preeminent suits you and start enjoying all your favorite harmony, gossip, and entertainment on the contact of a button.

Portable Satellite Radio and MP3 Player - XM XPMP3H1

Individual SiriusXM brings you added of pardon? you be keen on, all happening lone place. take pleasure in industrial-limitless harmony from practically each genre - together with musician-devoted channels. induce live sports act-by-play and 24/7 expert natter. have the benefit of exclusive entertainment and comedy. Plus the human race-lecture news, community traffic and weather, and added. elect amid the first-class, primary before All Access training package.

Honda Cb750f2 Electrical Wiring Diagram 1992circuit Schematic

Wiring Diagrams on Get More Information About Audi A4 Quattro Wiring Diagram Electrical

Get More Information About Audi A4 Quattro Wiring Diagram Electrical.

Wiring Diagrams on Honda Cb750f2 Electrical Wiring Diagram 1992 Circuit Schematic

Wiring Diagrams on Honda Cb750f2 Electrical Wiring Diagram 1992 Circuit Schematic

Honda Cb750f2 Electrical Wiring Diagram 1992 Circuit Schematic.

Wiring Diagrams on Volvo 740 And 760 Wiring Harness And Diagram 1984 1986

Wiring Diagrams on Volvo 740 And 760 Wiring Harness And Diagram 1984 1986

Volvo 740 And 760 Wiring Harness And Diagram 1984 1986.

Wiring Diagrams on 1987 Bmw E30 M3 Electrical Wiring Diagram Cable Harness Routing And

Wiring Diagrams on 1987 Bmw E30 M3 Electrical Wiring Diagram Cable Harness Routing And

1987 Bmw E30 M3 Electrical Wiring Diagram Cable Harness Routing And.

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Wiring Diagrams on Wiring Diagrams Trouble Code Diagnostic Charts And Updated Factory

Wiring Diagrams Trouble Code Diagnostic Charts And Updated Factory.

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Wiring Diagrams on Wiring Diagram Here Free Download Pdf File Source Mediafire

Wiring Diagram Here Free Download Pdf File Source Mediafire.

Wiring Diagrams on Virago Electric Starter Circuit And Wiring Diagram Circuit Schematic

Wiring Diagrams on Virago Electric Starter Circuit And Wiring Diagram Circuit Schematic

Virago Electric Starter Circuit And Wiring Diagram Circuit Schematic.

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Wiring Diagrams on Chevrolet Tahoe Blazer Electrical Wiring Diagram Circuit Schematic

Chevrolet Tahoe Blazer Electrical Wiring Diagram Circuit Schematic.

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Wiring Diagrams on Anti Theft System And Alarm Circuit Wiring Diagram Circuit Schematic

Anti Theft System And Alarm Circuit Wiring Diagram Circuit Schematic.

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Wiring Diagrams on About Volvo 940 Electrical System And Wiring Diagram Here

About Volvo 940 Electrical System And Wiring Diagram Here.

Thursday, April 11, 2013

Burglar Alarm Using LDR and BC 548

Description

Circuit showing a Burglar Alarm.Here we have used a ldr and a switching transistor for making this circuit
.When the light coming towards the ldr during the period the ldr have low resistance so the buzzer will on.When the light going away the ldr during the period the ldr have high resistance so the transistor will off.Here you need a 12 volt power supply

Components Required

Resistor

10 k(preset)

Transistor

BC 548

LDR

Buzzer

Source by : http://www.electronics-circuits.in/2012/03/burglar-alarm-ldr-bc-548.html

AM Receiver Circuit Diagram Using ZN414 IC

A.M. Antenna coil and MW gang connected in parallel. One popular level of this parallel circuit related to the IC ZN414 pin quantity 2.

Another standard point of that parallel circuit\r\n connected with two resistors (100kΩ, 1kΩ) in collection. A capacitor is \r\nconnected with the well-liked point of resistors (100kΩ, 1kΩ). A capacitor \r\nis linked in sequence with base of the transistor and the pin number 1 \r\nof the ZN414.

One finish of the 10kΩ resistor is connected with the collector level of the transistor BC549 and every other finish is connected with the ability provide +Vcc.

And\r\n one end of the 100kΩ resistor is hooked up with the collector and \r\nanother finish connected with base. 105pF capacitor is hooked up between \r\ncollector and ground. Pin three of IC ZN414 and emitter of the transistor is connected to the ground.

Required Instrument

IC ZN 414.
Capacitor(105pF×1,104pF×2,103pF×1)
MW Gang
Resistor(100kΩ×2,10kΩ×1,1kΩ×1,470Ω×1)
AM antenna
Transistor(BC549)

Electronic Touch Switch

Mechanical contacts have the disadvantage that they wear out. That is why it is practical to use an electronic ‘touch switch’ in some situations. With such a touch switch the resistance of the human skin is used for the switching action. The schematic shows the design of a circuit that senses the resistance of the skin and converts it into a useful switching signal. The touch switch contacts can be made from two small metal plates, rivets, nails, etcetera, which are placed close together on a non-conducting surface. In this circuit a comparator of the type LM393 has been used. In the idle state there is, via R1, a voltage equal to the power supply voltage on the non-inverting input of IC1a.

Because the inverting input of IC1a is set with R2 and D3 to D5 at the supply voltage minus 1.8 V, the open-collector output of IC1.a is, via R3, equal to the power supply voltage. This voltage is inverted by IC1.b. The voltage at the non-inverting input of IC1.b amounts to half the power supply voltage (through voltage divider R4 and R5) and is lower than the voltage on the inverting input.

Electronic Touch Switch Circuit diagram:

The output of IC1.b is therefore a ‘0’. If the two touch contacts are bridged with a finger, the voltage at the non-inverting input will become low enough to cause the comparator to toggle state. The moistness of the skin results in a resistance of 1 to 10 MR. If this circuit is used in the vicinity of equipment that’s connected to the mains, then it can be sufficient to touch only the upper contact to operate the switch, provided that the circuit has been earthed. The body then acts as an antenna which receives the 50 Hz (or 60 Hz) from the mains.

This is enough to toggle IC1.a at the same 50 Hz. C1/R3 prevent this 50 Hz from reaching the input of IC1b and provide a useable ‘pulse’ of about 10 s at the output of IC1.b. Note that a fly walking across the touch switch conducts enough to generate a switching signal. So do not operate important things with this circuit (such as the heating system or the garage door). Do not make the wires between the touch contacts and the circuit too long to prevent picking up interference. The power supply voltage for the circuit is not very critical. Any regulated DC voltage in the range from 6 to 20 V can be used.

Author: Heino Peters - Copyright: Elektor Electronics Magazine

Source : http://www.ecircuitslab.com/2011/06/electronic-touch-switch.html

Ultra Fast Battery charger circuit

Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] which will be discussed in this article is Fast NiCad Battery Charger, called the Ultra Fast Charger Battery Charger NiCad because it can make filling fast NiCad Batteries Cell. A battery charger in Desai has a fast charging capabilities such as Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] on this article shall be equipped with some ability to protect the battery and charger circuit itself.

Feature owned by Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad]

Autoshut-off, is the ability of the charger to stop charging current to a NiCad battery if the capacity NiCad battery is fully charged.
Polarity Protection, with the existence of this capability so if there are mounting the battery on the charger upside yan can be known.
Constant output voltage
Output currents enough to fill some NiCad batteries at once in parallel.
Short Circuit Protection, with the existence of this protection circuit so if there is short-circuit caused by a battery and a charger circuit itself will not damage the other parts are not damaged.
Series Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad]

Image series above is a series of schematic drawings for Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad]. Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] can be used for 8 to 10 NiCad batteries at once with 12 volt output voltage and max current is 3.5 A. The main components in the circuit of Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] is UC3843 and MC34181. UC3843 chip is a voltage regulator and M34181 is a JFET OpAmp with characteristic low offset voltage, input impedance is very high. MC34181 serves as a voltage comparator.

2000 Chevrolet 2500 Express Van Wiring Diagram

2000 Chevrolet 2500 Express Van Wiring Diagram

The Part of 1957-58 Dodge 4-Way Power Seat Wiring Diagram: power distribution, relay center,
ignition switch, fusible link, red wire, yellow wire, fuse block, starter motor, solenoid, generator, battery, black wire, fuse relay center, neutral position switch, starter relay, solenoid contacts, generator, black wire

Efficient Fan Speed Controller

A partial solution to quietening noisy PCs can be to reduce the speed of internal cooling fans. Low-cost fan speed controllers are available, but they often employ inefficient, heat-generating linear regulators and contain no temperature feedback mechanism. This idea makes use of a readily available, cheap in-car mobile phone charger. The majority of these use common circuitry and require only minor modifications to operate as efficient fan speed controllers complete with temperature feedback. Most in-car chargers are based on the well-known MC34063 DC-DC switchmode IC.

When used for charging mobile phones, the open-circuit output voltage is typically set to between 7V and 9V. This is achieved with a simple voltage divider across the output, the centre point of which connects to the feedback input (pin 5) of the MC34063. To make the output voltage var-iable with air temperature, first replace the upper resistor of the divider with a 4.7kΩ resistor in series with a 4.7kΩ trimpot. The lower half of the divider is then replaced with a 470Ω resistor in series with a 500Ω NTC thermistor. These values are only a guide and can be varied to suit different thermistor and fan types.

Circuit diagram:
efficient-fan-speed-controller-circuit diagram

efficient-fan-speed-controller-circuit diagram

Efficient Fan Speed Controller Circuit Diagram

Note that component lead length should be minimised to avoid introducing noise into the feedback circuitry. Getting the correct fan starting voltage is a matter of trial and error. The values shown on the circuit give a starting voltage of about 6.8V at room temperature but trimpot VR1 can be used to raise this voltage as necessary. The output can then rise to about 10V if the interior temperature rises sufficiently. The 4.7kΩ resistor could be reduced to 3.9kΩ and VR1 adjusted to give a lower starting voltage if the fan speed is still too high at 7V. After running for one hour or so, the fan voltage as set by the interior case temperature thermistor on my PC settled at 7.4V.

Suitable chargers are available from Oatley Electronics, Cat. No. 2D0074. They’re currently listed at $5 for two, which is less than the price of the MC34063 ICs alone! Data on the MC34063 can be downloaded from www.onsemi.com and a useful development aid is to be found at www.nomad.ee/micros/mc34063. Finally, note that not all chargers have an output filter capacitor installed. Typically, this is a 220µF 10V or 16V electrolytic type. To save a few cents, the manufacturers sometimes leave this component out, relying on the mobile’s battery to perform the filtering task. If this component is missing from your charger’s PC board, it should be installed before the supply is used.

Source by : Streampowers

Music On Hold for Telephones

Here is a simple circuit for music-on-hold with automatic shut off facility. During telephone conversation if you are reminded of some urgent work, momentarily push switch S1 until red LED1 glows, keep the telephone handset on the cradle, and attend to the work on hand. A soft music is generated and passed into the telephone lines while the other-end subscriber holds. When you return, you can simply pick up the handset again and continue with the conversation. The glowing of LED1, while the music is generated, indicates that the telephone is in hold position. As soon as the handset is picked up, LED1 is turned off and the music stops.

Music-On-Hold for Telephones Circuit diagram :

Normally, the voltage across telephone lines is about 50 volts. When we pick up the receiver (handset), it drops to about 9 volts. The minimum voltage required to activate this circuit is about 15 volts. If the voltage is less than 15 volts, the circuit automatically switches off. However, initially both transistors T1 and T2 are cut off. The transistor pair of T1 and T2 performs switching and latching action when switch S1 is momentarily pressed, provided the line voltage is more than 15 volts, i.e. when the handset is placed on the cradle. Once the transistor pair of TI and T2 starts conducting, melody generator IC1 gets the supply and is activated. The mu-sic is coupled to the telephone lines via capacitor C2, resistor R1, and the bridge rectifier.

With the handset off-hook after a ring, momentary depression of switch S1 causes forward biasing of transistor T2. Mean-while, if the handset is placed on the cradle, the current passing through R1 (connected across the emitter and base terminals of pnp transistor T1) develops enough voltage to forward bias transistor T1 and it starts conducting. As a consequence, output voltage at the collector of transistor T1 sustains for-ward biasing of transistor T2, even if switch S1 is released. This latching action keeps both transistors T1 and T2 in conduction as long as the output of the bridge rectifier is greater than 15 volts. If the handset is now lifted off-hook, the rectifier output drops to about 9 volts and hence latching action ceases and the circuit automatically switches off.

EFY lab note. The value of resistor R2 determines the current through resistor R1 to develop adequate voltage (greater than 0.65 volts) for conduction of transistor T1. Hence it may be test selected between 33 kilo-ohms and 100 kilo-ohms to obtain instant latching.) The total cost of this circuit is around Rs 50.

Source : http://www.ecircuitslab.com/2012/02/music-on-hold-for-telephones.html

Light Activated Switch Circuit Using LM311

This is a design circuit diagram of a light activated switch. This circuit is based on National Semiconductors comparator IC LM 311 and a LDR for operation. This is the figure of the circuit.

The circuit is based on a voltage comparator circuit wired around IC 1. The non-inverting in put of IC1 is given with a reference voltage of 6V using resistors R3 and R4. The input to the inverting input will be the voltage across the LDR that is light dependent. At darkness the resistance of the LDR will be high and so do the voltage across it. At this condition the voltage at the inverting input will be higher than the reference at non inverting pin and the out put of the comparator will be low(~o V). Adjust POT R1 to set the desired light intensity for switching the relay. For this illuminate the LDR with the desire intensity light.

The relay will be either on or off. Adjust POT R1 slowly so that the state of the relay changes. That’s it. Now the circuit is set for the given intensity of light. When the LDR is illuminated, its resistance drops and so do the voltage across it. Now the voltage at inverting input will be lower than that at non inverting input and the out put of the comparator goes high (~12 V). This makes transistor Q1 on and it drives the relay. As a result we get a relay switching according to the intensity of the light falling on the LDR.
You can use either a 12 V battery or a well regulated & filtered 12V DC mains operated power supply. The pin out of LM311 is also given together with the circuit diagram. The pin 5&6 (Balance & Balance/Strobe) of IC LM311 are shorted to minimize the chance of oscillations.

1991 Mazda B2600i Wiring Diagram


1991 Mazda B2600i Wiring Diagram

(click for full size image)

The Part of 1991 Mazda B2600i Wiring Diagram : battery, main fuse, main boa, btn, cruise control unit, carburetor, feed back carburetor, control unit, drl & rear wheel abs control unit, inhibitor switch, starter, ignition switch, engine control unit, ec-at control unit, engine control unit, circuit opening relay, drl & rear wheel abs control unit, alternator, alternator, instrument clusters.

Earth Fault Indicator Circuit

This is design circuit that used to indicates the integrity of wiring connections. It shows all the mains connections Phase, Neutral and Earth connections are intact or not. The circuit is too small and can be housed in a three pin plug case. This is the figure of the circuit;

The circuit is directly connected to mains to monitor the status of the connections. Earth connection is a must in domestic wiring to bleed current to the earth if the metal body of a device is accidentally touched with the phase line. This circuit indicates

1. Red and Green LEDs ON Phase, Neutral and Earth OK
2. Red and Green LEDs OFF Phase or Neutral Break / Power failure
3. Red LED ON Phase and Neutral OK
4. Green LED OFF Earth line break

The circuit gets power supply through C1 and R3. AC Capacitor C1 reduces the high volt AC to a safer level through capacitive reactance. Resistor R3 limits the inrush current and R4 gives discharge path for the stored current in C1 when the circuit is unplugged. Zener diode ZD regulates the voltage to a safer level to protect T1 when it is off. Voltage across ZD will be a square wave by the working of C1 and the voltage level depends on the breakdown value of zener (9 volts). When a potential of 230 volt is present between the phase and neutral lines, T1 turns on during the negative half cycle of AC and Green LED lights indicating that Earth connection is intact. This is because the base of T1 will be biased by the potential difference between the phase line and earth. If the earth connection is not intact, T1 will not get base bias and it remains off. Red LED lights during the positive half cycle of AC due to the potential difference between the phase and neutral lines. Enclose the circuit in a 3 pin plug and connect points A, B and C to the phase, neutral and earth pins respectively. Plug it into the 3 pin socket to test the wiring.

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