Electronic Circuits and Diagram-Electronics Projects and Design

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 designed to produce waveforms from 20Hz to 20 kHz.The ICL 8038 has to be operated from a dual power supply. Function…

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 Circuit Diagram with Parts List . Notes Inductor L1 is a UTC VC 15 variable inductor.If this is not available try…

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 four 1N 4007  Diodes. The resistor R2 must be twice the power of amp you are going to measure. To calibrate …

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 there is variation in the input supply the out put of each op amp goes high accordingly as they are wired…

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 the inverting terminal of the op-amp IC LM 358 gets amplified and its peak is detected by diode D4 and capacitor…

Water Level Indicator Description This is the circuit diagram of a simple corrosion free water level indicator for home and industries. In fact the 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 the bottom of tank. Next probes are placed step by step above the bottom probe. When water is…

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 set for  audio line voltage (1V peak to peak) and has a max  input voltage of 1.3V.   To make the circuit…

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. Power the circuit . Ground the negative lead of the volt meter and connect the positive lead to pins 6 and…