This electronic tester can be used to test electrical and electronic circuits and consists of an oscillator which generates a 1 kHz test signal and a detector which amplify and detects the signal and then make it audible with a small speaker or buzzer. IC1a chip functions as rectangular wave generator frequency determined by R4-C2 time constant. With values from the circuit diagram, the frequency is about 1 kHz and is less affected by supply voltage variations.
Using an integrated circuit CA3162 and some electronic components can be made a simple handheld voltmeter . In this digital voltmeter, the voltage measured is digitized in an analog-digital converter (A / D) and then displayed with three decimal. The display type is not usually seven segments, but consists of three groups of ten LEDs.
Range is up to 1V (at full scale), can be extended up to 10V or more, using the voltage divider R1-R2-R3.
This semiconductor tester can be used to test any semiconductor device, from switching diodes to power transistors. Tester is based on a single CMOS IC and a bicolor LED as a visual indication. Gate ICla forms a RC oscillator. Oscillator signal is passed through a buffer and delivered in the form of inverted and non-inverting by the two remaining free gates of IC.