This tester was found in a 90’s Popular Electronics. The integrated circuit is CMOS 4011. The indication is made through LED.
The TSC102 integrated circuit from ST-Microelectronics consists of a current sensor system that, in...
This circuit was found in old documentation, but the transistor may be the modern equivalent BC547....
The IC used in this project is not common these days, but if you have one you can build a high...