In this post I have explained how to build 10 simple yet useful function generator circuits using IC 4049, IC 8038, IC 741, IC 7400, transistors, UJTs etc. for generating accurate square waves, triangle waves, and sinewaves through easy switch operations. 1) Using IC 4049 Using only one low-cost CMOS IC 4049 and a handful […]
Meters and Testers
Grid Dip Meter Circuit
A dip meter or a grid dip meter can be considered as a kind of frequency meter whose function is to determine the resonant frequency of an LC circuit. For this, the circuits don’t have to ‘radiate’ any waves or frequency across each other. Instead, the procedure is implemented simply by placing the coil of […]
Circuit Tester Probe – PCB Fault-Finder
This simple circuit tester probe can be used for detecting short circuits, abnormal resistance conditions, continuity breaks etc inside an assembled circuit board or a PCB. The indication will be through an audible buzzer sound or an LED illumination. The described designs are all extremely safe to use even with PCBs that may have highly […]
Alcohol Detector Meter Circuit using MQ-3 Sensor Module
An alcohol detector is a sensitive device which is able to detect the presence of alcohol molecules or any similar volatile inflammable element in the air and convert it into equivalent level of electrical output. The simple alcohol detector circuit discussed here will accurately sense the emanation of alcohol gas from a selected source, such […]
Remote Control Infrared Tester Circuit
We all use remote control handsets for controlling various household devices such as TV, AC, Music systems, curtains etc, and sometimes we seem to have problems with these devices, or even a newly purchased remote controller unit occasionally seem to malfunction, and identifying the issue becomes quite difficult for us. This simple 2 transistor infrared […]
Capacitor Leakage Tester Circuit – Find Leaky Capacitors Quickly
This simple capacitor tester is capable of testing leaky electrolytic capacitors in the range of 1uf to 450uf. It can test large start and run capacitors as well as 1uf miniature capacitors rated at 10v. Once you understand the timing cycle, you can test down to 0.5uf and up to 650uf. By Henry Bowman How […]
