DMM range and AC-DC mode Logic
This is the third circuit that you will need to build a Simple Benchtop DMM with no Microcontroller. Here the U1D and U1B 4093 acts like a de-bouncing circuit for the push keys. The...
Tagged: DMM-Project
Power supply with battery backup – DMM
This is a simple charger circuit which will work for a light load like a DMM, the Battery can be a sealed maintenance free battery of 9V-2AH or better. The circuit will work best...
Build a DMM – LM3914 Analog display
This a part of a complete Benchtop DMM that you can build to learn the internals of a Digital MultiMeter. This is oriented towards learning the measurement aspects and the protection of input circuits....
AC conversion and Continuity – DMM
U1A LF353 opamp turns on a buzzer when the voltage at Test + falls very low indicating a short between Test + and Test – or a resistor less than 5 ohms. The R9-R14...
Voltmeter Attenuator Rectifier
Measurement of Voltage : – In testing electronic circuits, Measurement of voltages is important for diagnosing faults and making the circuits work. In circuit diagrams given in equipment manuals, voltages at various points in...
Voltage Attenuator Amp – DMM Project
LF356 opamp FET input is in a inverting amplifier configuration here. R4 + R5 make up Ri each 1/4 W MFR withstands 250V so both will take upto 500V. Use more in series for...
Analog and Digital Voltmeter using ICL7107
This Circuit is a DPM or digital panel meter. It has a analog bar graph display and a 3-1/2 digit digital display. ICL7107 is used in the 200mV configuration. U4A opamp LF353 amplifies the...
Resistance measurement with Current Source – DMM
U3 LF 356 is used as a constant current source (sink as the current is negative). R4, R5, R7 and R9 set the four resistance ranges by changing the constant current in decade steps....
