Function Generator Circuit

admin February 23, 2011 22 Comments
Function Generator Circuit Description. The ICL8038 is a function generator chip, capable of generating triangular, square , sine, pulse and sawtooth waveforms . From these sine, square & triangular wave forms can be made simultaneously.There is an option to control the parameters like frequency,duty cycle and distortion of these functions.This is the best function generator circuit for a beginner to start with and is of course a must on the work bench of an electronics hobbyist.The circuit here is...
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Audio Distortion Meter

admin February 23, 2011 1 Comment
Audio Distortion Meter Description Here is a simple 1KHz audio distortion meter that can measure the Total Harmonic Distortion (THD) on any load at any out put power.Here you have the option to select 2,4,8 or 16 Ohm loads. The circuit works by filtering the 1 kHz fundamental signal using a notch filter comprising of L1,C2,C1,R1. With a little time and calculation you can get the correct THD of your amplifier in such a simple way. Audio Distortion Meter...
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Audio Wattmeter Circuit

admin February 23, 2011 4 Comments
Audio Watt Meter Description This is an easy trick to measure the output of an amplifier.Here resistor R2 acts as the load for for the amp and it should be able to withstand twice the maximum power of the amp you are going to measure.The meter scale must be calibrated and with a little effort you can get good results. Audio Watt meter Circuit Diagram with Parts List. Notes If 1A bridge is not available , make one with...
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Voltmeter circuit using LED

admin February 22, 2011 16 Comments
Car Battery Voltmeter Circuit Description This is a very useful circuit which when installed on your car gives the voltage of you car battery in a LED dot display form.The circuit is based on four comparators made of quad op amp LM324.The inverting inputs of IC are kept at at reference voltages 5.6V,5.2V,4.8V,4.4V respectively at pins 2,6,9,13 by resistors ,R3,R4,R5,R6.The battery voltage is directly fed to the pin inverting input through the voltage divider arrangement using R1 and R7.When...
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InfraRed (IR) Sensor/Detector

jacky November 22, 2011 11 Comments
InfraRed (IR) Sensor/Detector Circuit Description. The circuit shows that the output of IC1 555 IC,which is designed for a duty cycle of 0.8mSec,with a frequency of 120Hz and 300 mA peak current, is used to drive the infra red LED,D1.From the connection it is clear that the diodes D1 and D2 are on the same line,just a few centimeters apart, on the breadboard.Thus diode D2 receives the infra-red output from the diode D1.The diode signal, which is given to...
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water level indicator

Simple Water Level Indicator

jacky July 21, 2018 271 Comments
Water Level Indicator Description This is the circuit diagram of a simple corrosion free water level indicator for home and industries. In fact, the level of any conductive non-corrosive liquids can be measured using this circuit. The circuit is based on 5 transistor switches. Each transistor is switched on to drive the corresponding LED when its base is supplied with current through the water through the electrode probes. One electrode probe is (F) with 6V AC is placed at...
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Sound Level Meter

jacky April 11, 2011 4 Comments
Sound Level Meter Circuit Description This is a one chip sound level meter that can be use for displaying sound level of an amplifier or simply the sound level from a microphone.The heart of the circuit is  IC LM 3915 Audio level IC.Even though it is a stand alone IC , a peak detector based on Transistor BC 558  and diode 1N4001  is also included for better performance. Tips Supply voltage  can be  from 3V to 20V.The input is...
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LED Thermometer for Temperature Measurement

jacky November 23, 2011 10 Comments
LED Thermometer – Temperature Measurement Circuit Description The circuit given here is a precision LED bar graph Fahrenheit thermometer,which can be used as a temperature measurement circuit, build around IC LM 34 (sensor) and IC LM 3914 (bar graph driver). The circuit can be modified to read in degree Celsius by replacing sensor LM 34 with LM 35. Both are inter changeable. The circuit operates of a volt power supply. To calibrate the circuit, you will need a voltmeter....
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