Wednesday, December 25, 2013

Best Electronic Crowbar Circuit Diagram for AC or DC lines

This is Best Electronic Crowbar Circuit Diagram for AC or DC lines. For positive protection of electrical or electronic equipment, use this against excessive supply voltage. Due to improper switching, wiring, short circuits, or failure of regulators, an electronic crowbar circuit can quickly place a short circuit across the power lines, thereby dropping the voltage across the protected device to near zero and blowing a fuse. 

The triac and SBS are both bilateral devices, the circuit is equally useful on ac or dc supply lines. With the values shown for Rl, R2, and R3, the crowbar operating point can be adjusted over the range of 60 to 120 volts dc or 42 to 84 volts ac. The resistor values can be changed to cover a different range of supply voltages. The voltage rating of the triac must be greater than the highest operating point as set by R2, II is a low power incandescent lamp with a voltage rating equal to the supply voltage. 

Best Electronic Crowbar Circuit Diagram for AC or DC lines

Best Electronic Crowbar Circuit Diagram for AC or DC lines

It may be used to check the set point and operation of the unit by opening the test switch and adjusting the input or set point to fire the SBS. An alarm unit such as the Mallory Sonalert may be connected across the fuse to provide an audible indication of crowbar action. (This circuit may not act on short, infrequent power line transients).
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Sunday, December 22, 2013

Photodiode Alarm

This Photodiode based Alarm can be used to give a warning alarm when someone passes through a protected area. The circuit is kept standby through a laser beam or IR beam focused on to the Photodiode. When the beam path breaks, alarm will be triggered. The circuit uses a PN Photodiode in the reverse bias mode to detect light intensity. In the presence of Laser / IR rays, the Photodiode conducts and provides base bias to T1. The NPN transistor T1 conducts and takes the reset pin 4 of IC1 to ground potential. IC1 is wired as an Astable oscillator using the components R3, VR1 and C3. The Astable operates only when its resent pin becomes high. When the Laser / IR beam breaks, current thorough the Photodiode ceases and T1 turns off. The collector voltage of T1 then goes high and enables IC1. The output pulses from IC1 drives the speaker and alarm tone will be generated.

Photo-Diode Alarm Circuit diagram


IR Transmitter Circuit diagram

A simple IR transmitter circuit is given which uses Continuous IR rays. The transmitter can emit IR rays up to 5 meters if the IR LEDs are enclosed in black tubes.
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Thursday, December 19, 2013

Luggage Security System

While traveling by a train or bus, we generally lock our luggage using a chain-and-lock arrangement. But, still we are under tension, apprehending that somebody may cut the chain and steal our luggage. Here is a simple circuit to alarm you when somebody tries to cut the chain. Transistor T1 enables supply to the sound generator chip when the base current starts flowing through t. When the wire (thin enameled copper wire of 30 to 40 SWG, used or winding transformers) loop around the chain is broken by somebody, the base of transistor T1, which was earlier tied to positive rail, gets opened. As a result, transistor T1 gets forward biased to extend the positive supply to the alarm circuit. In idle mode, the power consumption of the circuit is minimum and thus it can be used for hundreds of travel hours.

Luggage Security System

To enable generation of different alarm sounds, connections to pin 1 and 6 may be made as per the table.

Select 1 (Pin6) Select 2 (Pin1) Sound effect
X X Police siren
VDD X Fire-engine siren
VSS X Ambulance siren
“-” VDD Machine-gun sound
Note: X = no connection; “-” = do not care

Source: http://www.ecircuitslab.com/2011/05/luggage-security-system.html
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Tuesday, October 8, 2013

Lie Catcher


Here is a circuit that you can have fun with your friends. Especially you can catch your girl friend or your boy friend when ever they say lies. Circuit is very simple and you can build it with in few hours. But you will surprise with the results.
.
For two electrodes you can use wires but to get best results use electrode pads which use in the hospitals. Attach the electrode pads to the back of the hand from one inch apart. Make sure meter should be zero before you start. If the person is lying the meter point will get move.

To operate the circuit it needs two voltages separately as shown in the diagram. You can use alkaline batteries for long use or two 4.5 V two power packs if you want.


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Saturday, October 5, 2013

2010 Ford Ranger XL Wiring Diagram

2010 Ford Ranger XL Wiring Diagram
(click for full size image)

The Part 2010 Ford Ranger XL Wiring Diagram: antena, cluster, panel illumination, sense, low current board, junction box, audio untit, power distribution, four door, speaker.

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Wednesday, October 2, 2013

Electronic Ear for Lego RCX Module

One interface that is missing in the Lego MindStorms system is an electronic ear. We don’t mean that the RCX should respond to spoken commands (which requires a large amount of electronics and software), but it would be handy if it could respond to basic sounds (or sound levels). The circuit presented here allows the RCX to sense different sound levels. The sound is picked up by a crystal microphone, which is an inexpensive component that is available in every electronics shop. The signal from the microphone is converted into a variable quasi-resistance value. The RCX, in turn, can use this value to determine if a particular sound level has been exceeded. If the trigger threshold is set to the right level, the RCX will then react to a previously set sound level. The RCX input must be configured as a light sensor input for this function.

Electronic Ear for Lego RCX ModuleThe operation of the circuit is simple. IC1, which is wired as a non-inverting amplifier, amplifies the microphone signal by a factor of 100. The output signal from the opamp is rectified by D1 and smoothed by C1. Resistor R2 allows the capacitor to discharge. The resulting DC voltage drives IC2, which acts as a buffer. The output of this opamp is connected to the sensor input of the RCX via a 1-kΩ resistor (R1). Just as with the analogue input adapter described elsewhere in this website, the RCX sees a variable resistance value at the sensor input, and it converts this into a measurement value between 0 and 100.

In the idle state, when no sound is sensed, the measurement value lies between 90 and 100. The louder the sensed sound, the lower the measurement value. You can use the light-sensor routine of the Lego software to set the responses to various sound levels. If you use a threshold value of around 85, then a level under 85 will be sensed as a sound signal, while a level above 85 will be sensed as silence. If you clap your hands near the sensor, the circuit will detect this. If you use these ‘observations’ to increment a counter, it is even possible to measure the number of sound pulses within a defined interval, and then to carry out some action based on the result.
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Sunday, September 29, 2013

1940 Chevrolet Passenger Electrical Wiring Diagram

1940 Chevrolet Passenger Electrical Wiring Diagram
The Part of 1940 Chevrolet Passenger Electrical Wiring Diagram: cigarette lighter, light ignition, battery, coil, generator,  light meter speed, ceiling unit gauge fuel tank and rear lights, stop horn relay, voltage regulator, horn relay, instrument light dimmer, circuit breaker, starter, stop light switch, license plate light, dome light, headlamp beam indicator, speedometer light.
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Thursday, September 26, 2013

Low Noise Microphone Amplifier OP270E

The signal from a microphone is two weak for a standard line input. This low-noise DC-coupled microphone amplifier provides a solution for anyone who wants to connect a microphone to his or her hi-fi installation. As can be seen from the schematic diagram, a good circuit does not have to be complex. A differential amplifier is built around T1 (MAT-03E), which is a low-noise dual transistor. The combination of T2 and LED D1 forms a constant-current source for the input stage. A low-noise opamp (OP-270E) amplifies the difference signal that appears at the collectors of the dual transistor. The result is an analogue signal at line level.

Low-Noise Microphone Amplifier Circuit Diagram Using Operational amplifier (OP270E)The bandwidth of the amplifier ranges from 1 Hz to 20 kHz. Within the audio range (20 Hz to 20 kHz), the distortion is less than 0.005 percent. Since only half of the OP-270E is used, the remaining opamp could be used in the output stage of a stereo version. The amplifier can be powered from a stabilized, symmetrical supply with a voltage between ±12 V and ±15 V. Such supply voltages are already present in many amplifier.
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Monday, September 23, 2013

A Car Battery Monitor

A close call on the road can really focus your mind on the importance of having a battery monitor in a car. I had been enjoying a pleasant week of travelling around the countryside at a leisurely pace and taking in the beautiful scenery each day. It wasnt until the final day, with the big rush to return home, that I had to drive at night.My home is deep in the country and on the road I was travelling the closest petrol station may be 80km away. I was travelling through an area that is full of open-cut coal mines and large heavily loaded semi-trailers constantly pound the roads, travelling at quite high speeds. It was around 8pm at night and everything was very dark no street lights or house lights anywhere.

Just as I was going up a hill, the lights began to dim and the engine coughed. A large semi-trailer loomed in the rear-vision mirror as I pushed the clutch in and tried to restart. My speed was falling rapidly and my lights were blacked out - I was like a sitting duck in the middle of the road, as the semi-trailer came rapidly bearing down on me. I just managed to pull the car off the road, as the semi-trailer came screaming past, missing me by inches! After calling for assistance from the NRMA, the problem was found to be a fault in the alternator, which was failing to charge the battery. The battery voltage had been falling under the heavy load of the lights and at the worst possible time, there was not sufficient power for the lights or the motor.

After the initial shock wore off, I put on my thinking cap to come up with a PIC-based solution to the problem. What was really needed was a display and a buzzer, to get my attention should the voltage fall outside a specified range. So my design criteria was set, a series of LEDs could indicate the voltage and a buzzer would also be used to warn of problems.
Main Features:
  • Visual indication of battery voltage
  • Audible warning when voltage becomes low
  • Screw terminals for easy connection
  • Simple and easy to build
Circuit details:

The circuit is based on PIC16F819 18-pin microcontroller which has an analog-to-digital (A/D) input to monitor the battery voltage and outputs capable of driving LEDs directly, to keep the component count down. There are seven LEDs in all, giving a good range of voltage indication. The topmost LED, LED1, comes on for voltages above 14V which will occur when the battery is fully charged. LED2 indicates for voltages between 13.5V and 14V while LED3 indicates between 13V and 13.5V. Normally, one of these LEDs will be on. LED4 covers 12.5V to 13V while LED5 covers 12V to 12.5V. LED6 covers from 11.5V to 12V while LED7 comes on for voltages below 11.5V. These two LEDs are backed up by the piezo chime which beeps for voltages between 11.5V and 12V and becomes more insistent for voltages below 11.5V.

That might seem fairly conservative. After all, most cars will start with no troubles, even though the battery voltage might be a touch below 12V, wont they? Well, no. Some modern cars will happily crank the motor at voltages below 11V but their engine management will not let the motor start unless the voltage is above 11V. So dont think that a modern car will always start reliably. This little battery monitor could easily prevent a very inconvenient failure to start! So lets describe the rest of the circuit. The incoming supply is connected via diode D1 which provides protection against reverse polarity while zener diode ZD1 provides protection from spike voltages.

A standard 7805 3-terminal regulator is then used to provide a stable 5V to the microcontroller. The battery voltage is sensed via a voltage divider using 33kΩ and 100kΩ resistors. This brings the voltage down to within the 0-5V range for the A/D input of the PIC16F819. Port B (RB0 to RB7) of the microcontroller is then used to drive the various LEDs, with current limiting provided via the 330Ω resistor network. RB7, pin 13, drives a switching transistor for the piezo buzzer.

Software:

For the software, the design follows the basic template for a PIC microcontroller. Port A and its ADC (analog-to-digital converter) function are set up while port B functions as the output for the LEDs and buzzer. Once the set-up is complete, a reading will be taken at port RA2, the input for the A/D convertor. This reading is then compared with a series of values to determine the range of the voltage. This is similar to a series of "if" statements in Basic language. If the voltage is found to be within a certain range, the relevant port B pin will be turned on. If the voltage is below 12V, the buzzer will be turned on for a brief period, to signal a low battery condition. As the voltage falls below 11.5V, the frequency of the beeps will increase, to signal increased urgency.

Building it:

All the parts are mounted on a small PC board measuring 46 x 46mm (available from Futurlec). The starting point should be the IC socket for the PIC16F819, as this is easiest to mount while the board is bare. The next item can be the PC terminal block. The resistors and capacitors can then follow. Make sure the electrolytics are inserted with correct polarity.

Make sure that you do not confuse the zener (ZD1) with the diode when you are installing them; the diode is the larger package of the two.

Even more important, dont get the 78L05 3-terminal regulator and the 2N3906 transistor mixed up; they come in identical packages. The 78L05 will be labelled as such while the 2N3906 will be labelled "3906". And make sure you insert them the correct way around. The buzzer must also be installed with the correct polarity. The 330Ω current limiting resistors are all in a 10-pin in-line package. There are four green LEDs, two yellow and one red. They need to be installed in line and with the correct orientation.

Testing:

Before you insert the PIC16F819 microcontroller, do a voltage check. Connect a 12V source and check for the presence of 5V between pins 14 & 5 OF IC1. If 5V is not present, check the polarity of regulator REG1 and the polarity of the diode D1. If these tests are OK, insert the IC and test the unit over a range of voltage between 9V and 15V. Make sure that all LEDs come on in sequence and the piezo buzzer beeps for voltages below 12V.

Now it is matter of installing the unit in your car. It is preferable to install the unit in a visible position for the driver. However, it should not obscure any other instruments. The unit should be connected to the cars 12V supply after the ignition switch. This will turn the unit off with the other instruments and prevent battery drain while the motor is not running.

Author :Alan Bonnard Copyright : Silicon Chip Publications Pty Ltd

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Friday, September 20, 2013

1995 Mercedes Benz c 220 Wiring Diagram

1995 Mercedes-Benz c 220 Wiring Diagram
(click for full size image)

The Part of  1995 Mercedes-Benz c 220 Wiring Diagram :instrument cluster, connector, pushbutton control,  valve block, control module, temperature, run, fuse box, control speed, traction ctrl, auxiliary, copressor, refrigerant.
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Wednesday, September 11, 2013

Wireless Sensor Applications using Dorji’f DRF5150S and DRf4432S Modules

Dorji Applied Technology from China builds different types of RF modules that can be easily incorporated in designing wireless data loggers, sensor network, telemetry and other wireless applications.

Wireless Sensor Applications using Dorji’f DRF5150S and DRf4432S Modules

Some of their RF modules have an additional pre-programmed microcontroller that allows direct interface of selected analog and digital sensors to the module. This means you don’t need any external MCU or to write codes for these sensors. In this tutorial, Raj from Embedded Lab talks about their DRF5150S and DRF4432S RF modules which are very versatile and easy to use for wireless sensor applications. For illustrative purpose, Raj shows how to put them together to construct a simple wireless sensor application where data from a remote sensor are received and displayed on a PC, without using any external microcontrollers.
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Thursday, September 5, 2013

Sound Operated Switch Circuit

Circuit Diagram 
Notes:
  • This sensitive sound operated switch can be used with a dynamic microphone insert as above, or be used with an electret (ECM) microphone. If an ECM is used then R1 (shown dotted) will need to be included. A suitable value would be between 2.2k and 10kohms.
  • The two BC109C transitors form an audio preamp, the gain of which is controlled by the 10k preset. The output is further amplified by a BC182B transistor. To prevent instability the preamp is decoupled with a 100u capacitor and 1k resistor. The audio voltage at the collector of the BC182B is rectified by the two 1N4148 diodes and 4.7u capacitor. This dc voltage will
  • directly drive the BC212B transistor and operate the relay and LED.
  • It should be noted that this circuit does not "latch". The relay and LED operate momentarily in response to audio peaks. 
Source - http://www.electronics-lab.com/
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    Monday, September 2, 2013

    IR illuminator for Night Vision Tv Cameras and Scopes

    This source uses LEDs and an astable oscillator to control the switch, duty-cycle, and effective IR illumination output.

     Circuit Diagram

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    Wednesday, August 14, 2013

    Read Circuit Wiring Diagramsehow

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    Of Content How To Use This Manual Wiring And Electric Parts Symbols.


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    New Electrical Service Home Residential Wiring Diy Advice.


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    Circuit Diagram Software Recommendations Diybanter.


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    Same Symbols E G Wiring Symbols Http Hampgh Com Classmaterials Aspx.


    Wiring Diagram Symbols on What Is Schematic Diagram     Circuit Schematic
    What Is Schematic Diagram Circuit Schematic.


    Wiring Diagram Symbols on Wiring Requires Knowledge Of The Symbols Used In Wiring Diagrams
    Wiring Requires Knowledge Of The Symbols Used In Wiring Diagrams.


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    Sunday, August 11, 2013

    Thermometer Based on Mikrokontroler AT89S52

    Thermometer Based on Mikrokontroler AT89S52
    Thermometer Based on Mikrokontroler AT89S52
    This is a circuit of a microcontroller AT89S52 thermometer and LTC1298 12-bit ADC, programs written in C language program with digital filtering and interface the LED display. Reading provides a sensitivity 0.1C.

    The hardware block and circuit diagram is shown in the figure below. The thermistor sensor is epoxy. The signal conditioning circuit is a simple voltage divider. The ADC is 12-bit SPI interface LTC1298 analog to digital. Atmels Microcontroller 89S52. The 0.5 inch display has four digits of 7 segments. The driver of the segment offers 32-bit CMOS output.

    The 12-bit ADC (LTC1298 or MC3202) are two channels, CH0 and CH1. The signal from ADC input channel 0 thermistor voltage divider is simple. Channel 1 is available for other sensors. The example shown in the diagram is the HIH-3160 Honeywell Relative Humidity Sensor. The ADC chip interconnects with MCU 89S52 with P1.1, P1.2 and P1.3. The LED display has 4 digits. The CMOS shift register 4094 directly drives the LED
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    Thursday, August 8, 2013

    Multi Position Mains Switch

    The circuit shown here was born out of necessity after one of our colleagues had just renovated his kitchen and realized afterwards that there were not enough switches. Obviously he was not too keen to partially demolish the kitchen to install a few additional wires in the already tiled wall. That’s how the idea arose to develop a clever electronic circuit that would operate two lamps with only one switch. All this appeared to be easy to realize by adding a small circuit, consisting of a decade counter, a diode network, two relays and a low voltage power supply.

    Multi-Position Mains Switch circuit diagram
    The schematic shows how simple the design of the ‘multi-position‘ extension really is. K3 is connected to the switched wires that go to the original light. K1 and K2 are the connections for the two new lamps. The operation is simply based on the fact that at every low to high transition at the CLK input of IC1 the active output moves over by one position. In combination with the diode network D4 through D7 this ensures that with a single wall switch it becomes possible to control two outputs. When the mains voltage is applied to K3 for the first time, Q0 will be high and Re1 will be energized.

    Multi-Position Mains Switch circuit diagram
    When the mains switch is briefly switched off and then on again it will have no consequences for the 9-V power supply, because C4 is quite large. But this will result in a trigger pulse on the CLK input, so that Q1 will now be high and via D5 and D6 both relays are energised. After another off/on cycle of the mains switch, Q2 will be high, relay Re1 will de-energise and only Re2 is still activated. If we repeat the off/on cycle once more we’re back at the starting position and only Re1 is energized.

    Multi-Position Mains Switch circuit diagram
    If the switch remains in the ‘off’ position then both relays will also be off. A printed circuit board has been designed for this extension so that the entire circuit will fit without any problems in a waterproof enclosure from OKW, Bopla or Schyller. The 9V transformer is also fitted on the PCB. PCB screw terminals can be used for K1, K2 and K3. Since the circuit is directly connected to the mains voltage we emphasis that the well-known safety rules need to be observed. When making any measurements or performing other operations on the circuit is it absolutely necessary to first break the connection to K3!

    Multi-Position Mains Switch circuit diagramResistors:
    • R1,R2 = 10kΩ
    • R3 = 33kΩ
    • R4 = 100kΩ
    • R5 = 10kΩ
    Capacitors:
    • C1 = 100nF
    • C2 = 10µF 63V
    • C3 = 4µF7 63V radial
    • C4 = 470µF 16V radial
    • C5 = 2µF2 63V axial
    Semiconductors:
    • D1-D7 = 1N4148
    • D8 = 1N4001
    • T2,T3 = BC547B
    • IC1 = 4017
    • IC2 = 78L09
    Miscellaneous:
    • K1,K2,K3 = 2-way PCB
    • terminal block, lead pitch 7.5mm
    • T r1 = mains transformer 9V 1.5VA
    • B1 = B80C1500 (round case) (80V piv, 1.5A)
    • Re1, Re2 = 12V relay
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    Monday, August 5, 2013

    Simple 12 16V Converter Circuit Diagram

    This is simple 12 -16V converter circuit diagram . Many devices operate from a car`s 12-V electrical system. Some require 12 V; others require some lesser voltage. An automobile battery`s output can vary from 12 to 13.8 V under normal circumstances. The load requirements of the device might vary. 

    This circuit maintains a constant voltage regardless of how those factors change. Simple circuit, A, uses a 7805 voltage regulator.In addition to a constant output, this JC provides overload and short-circuit protection. That unit is a 5-V, 1-A regulator, but when placed in circuit B, it can provide other voltages as well. When the arm of potentiometer R1 is moved toward ground, the output varies from 5 to about 10 V. 


     Simple 12 -16V Converter Circuit Diagram


    Simple 12 -16V Converter Circuit Diagram
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    Friday, August 2, 2013

    Happy Couse Very usefull using Schumacher XC103 SpeedCharger

    Schumacher XC103 SpeedCharge Battery Charger with Engine Start yes Richard Smith Happy couse Very usefull  Schumacher XC103 SpeedCharger Schumacher XC103 SpeedCharge Battery Charger 
    It showed up on time and I put it right to work. It operates perfectly. I have had many Shumaker battery chragers in my day and thats why I keep buying them. Works great so easy to use this charger dose it all from my boat batteries or motor home or motorcyle, its all automatic and not cheap junk its really heavy built

    Click here to know price and buy Schumacher XC103 SpeedCharge Battery Charger with Engine Start
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    Tuesday, July 30, 2013

    Heating System Thermostat Circuit

    This circuit is intended to control a heating system or central heating plan, keeping constant indoor temperature in spite of wide range changes in the outdoor one. Two sensors are needed: one placed outdoors, in order to sense the external temperature; the other placed on the water-pipe returning from heating system circuit, short before its input to the boiler.The Relay contact wiring must be connected to the boilers start-stop control input. This circuit, though simple, has proven very reliable: in fact it was installed over 20 years ago at one of my friends home. I know, it is a bit old: but it is still doing its job very well and without problems of any kind.




    Parts:

    P1 = 1K Linear Potentiometer
    R1 = 10R-1/4W Resistor
    R2 = 1K-1/4W Resistor
    R3 = 3K3 @ 20°C n.t.c. Thermistor (see Notes)
    R4 = 2K2 @ 20°C n.t.c. Thermistor (see Notes)
    R5 = 10K-1/2W Trimmer Cermet
    R6 = 3K3-1/4W Resistor
    R7 = 4K7-1/4W Resistors
    R8 = 470K-1/4W Resistor
    R9 = 4K7-1/4W Resistors
    R10 = 10K-1/4W Resistor
    C1 = 470µF-25V Electrolytic Capacitors
    C2 = 470µF-25V Electrolytic Capacitors
    C3 = 1µF-63V Electrolytic Capacitor
    D1 = 1N4002 - 100V 1A Diodes
    D2 = 1N4002 - 100V 1A Diodes
    D4 = 1N4002 - 100V 1A Diodes
    D3 = LED Red 3 or 5mm.
    Q1 = BC557 - 45V 100mA PNP Transistor
    Q2 = BC547 - 45V 100mA NPN Transistor
    Q3 = BC337 - 45V 800mA NPN Transistor
    J1 = Two ways output socket
    T1 = 220V Primary, 12 + 12V Secondary 3VA Mains transformer
    PL1 = Male Mains plug &cable
    SW1 = SPST Mains Switch
    RL1 = Relay with SPDT 2A @ 220V switch Coil Voltage 12V. Coil resistance 200-300 Ohm

    When Q1 Base to ground voltage is less than half voltage supply (set by R7 & R9), a voltage is generated across R8 and the driver transistors Q2 & Q3 switch-on the Relay. When Q1 Base to ground voltage is more than half voltage supply, caused when one of the n.t.c. Thermistors lowers its value due to an increase in temperature, no voltage appears across R8 and the Relay is off. C3 allows a clean switching of the Relay. P1 acts as main temperature control.

    Notes:

    * R3 is the outdoor sensor, R4 the indoor sensor.
    * If you are unable to find a 3K3 Thermistor for R3 you can use a 4K7 value instead. The different value can be easily compensated by means of Trimmer R5.
    * R5 allows setting the heating system for outdoor temperatures ranging from about +10°C downwards. The higher R5s resistance the hotter the heating system and vice versa.
    * The existing boiler thermostat should be set to its maximum value and not bypassed: it is necessary for safetys sake.
    * This circuit can be dispensed with its differential feature and converted into a simple precision thermostat omitting R3.




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    Wednesday, June 12, 2013

    Signal Isolation Bags

    Earlier study indicated that, although mobile phones and other portable electronic products bring the people the convenience of communication and exchange, they are "eating" less and less of our time pieces, so many people suffer from a "mobile phone addiction." and here this product is designed to address this issue.

    This designer bags that allow you to isolate the signal can temporarily allow communication devices such as mobile phones from your side "disappear." Lined bags are coated with colloidal silver, both radio frequency isolation, but can also phone sterilization, the true sense of the times you return to no signal. In addition, this signal isolation bags in various sizes, suitable for most currently available mobile phones and tablet PCs. I do not know why, I can not help but think of the iPhone4 "death grip." . .
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    Friday, May 31, 2013

    Wiring Regulationssetting Standards Electrical Installations

     Wiring Regulations on City And Guilds Exam Success   Iee Wiring Regulations    Paperback  By
    City And Guilds Exam Success Iee Wiring Regulations Paperback By.


     Wiring Regulations on Guide To The Wiring Regulations 2008  Iee Wiring Regulations  Bs 7671
    Guide To The Wiring Regulations 2008 Iee Wiring Regulations Bs 7671.


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    17th Edition Iee Wiring Regulations.


     Wiring Regulations on Iee Wiring Regulations  Bs 7671 2008  And Part P Of Building
    Iee Wiring Regulations Bs 7671 2008 And Part P Of Building.


     Wiring Regulations on Bs 7671  Iee Wiring Regulations  17th Edition
    Bs 7671 Iee Wiring Regulations 17th Edition.


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    Iee Wiring Regulations Design And Verification Of Electrical.


     Wiring Regulations on Work   Updated To Iee Wiring Regulations 17th Edition Bs 7671  2008
    Work Updated To Iee Wiring Regulations 17th Edition Bs 7671 2008.


     Wiring Regulations on Iee Wiring Regulations   Setting Standards In Electrical Installations
    Iee Wiring Regulations Setting Standards In Electrical Installations.


     Wiring Regulations on Bathroom Lighting Zones
    Bathroom Lighting Zones.


     Wiring Regulations on Guide To The 15th Edition Of The Iee Wiring Regulations E Book   Zella
    Guide To The 15th Edition Of The Iee Wiring Regulations E Book Zella.


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    Monday, May 13, 2013

    Personal Alarm

    Personal AlarmThis circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and connected to the hand or the clothes of the person carrying the bag by means of a tiny cord.
    If the bag is snatched abruptly, the magnet looses its contact with the reed switch, SW1 opens, the circuit starts oscillating and the loudspeaker emits a loud alarm sound.


    The device can be reverse connected, i.e. the box can be placed in a pocket and the cord connected to the bag.
    This device can be very useful in signalling the opening of a door or window: place the box on the frame and the magnet on the movable part in a way that magnet and reed switch are very close when the door or window is closed.
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    Sunday, May 5, 2013

    Brightness Control for small Lamps

    This device was designed on request, to control the light intensity of four filament lamps (i.e. a ring illuminator) for close-up pictures with a digital camera, powered by two AA or AAA batteries. Obviously it can be used in other ways, at anyones will.
    IC1 generates a 150Hz squarewave having a variable duty-cycle. When the cursor of P1 is fully rotated towards D1, the output positive pulses appearing at pin 3 of IC1 are very narrow. Lamp LP1, driven by Q1, is off as the voltage across its leads is too low. When the cursor of P1 is rotated towards R2, the output pulses increase in width, reaching their maximum amplitude when the potentiometer is rotated fully clockwise. In this way the lamp reaches its full brightness.


    LP1 could be one or more 1.5V bulbs wired in parallel. Maximum total output current allowed is about 1A.
    R2 limits the output voltage, measured across LP1 leads, to 1.5V. Its actual value is dependent on the total current drawn by the bulb(s) and should be set at full load in order to obtain about 1.5V across the bulb(s) leads when P1 is rotated fully clockwise.




    Parts:
    P1 470K Linear Potentiometer
    R1 10K 1/4W Resistor
    R2 47K 1/4W Resistor (See Notes)
    R3 1K5 1/4W Resistor
    C1 22nF 63V Polyester Capacitor
    C2 100µF 25V Electrolytic Capacitor
    D1,D2 1N4148 75V 150mA Diodes
    IC1 7555 or TS555CN CMos Timer IC
    Q1 BD681 100V 4A NPN Darlington Transistor
    LP1 1.5V 200mA Bulb (See Notes)
    SW1 SPST Switch
    B1 3V (Two 1.5V AA or AAA cells in series, etc.)
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    Wednesday, May 1, 2013

    9V Battery Replacement Power Supply

    This circuit was originally designed to power a motorcycle intercom from the vehicle supply system. This type of intercom, which is used for communication between driver and passenger, generally requires quite a bit of power. In order to improve intelligibility there is often elaborate filtering and a compander is sometimes used as well. The disadvantage is that a battery doesn’t last very long. You could use rechargeable batteries, of course, but that is often rather laborious. It seems much more obvious to use the motorcycle power supply instead. A 9-V converter for such an application has to meet a few special requirements.

    9V Battery Replacement Power Supply
     
    For one, it has to prevent interference from, for example, the ignition system reaching the attached circuit. It is also preferable that the entire circuit fits in the 9-V battery compartment. This circuit meets these requirements quite successfully and the design has nonetheless remained fairly simple. In the schematic we can recognize a filter, followed by a voltage regulator and a voltage indicator. D1, which protects the circuit against reverse polarity, is followed by an LC and an RC filter (C3/L1/L2/C1/R1/C2). This filter excludes various disturbances from the motorcycle power system.

    Moreover, the design with the 78L08 and D3 ensures that the voltage regulator is operating in the linear region. The nominal system voltage of 14 V can sometimes sag to about 12 V when heavy loads such as the lights are switched on. Although the circuit is obviously suitable for all kinds of applications, we would like to mention that it has been extensively tested on a Yamaha TRX850. These tests show that the converter functions very well and that the interference suppression is excellent.
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    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

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    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.
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