Based on CMOS logic this short-circuit locator circuit uses the ear's ability to detect small changes in pitch, which are caused by variations in millivolts in a track under analysis.
The circuit shown is suggested by National Semiconductor's Linear Applications Handbook. The base...
This circuit uses a pickup coil to take the signal from a telephone line without contacts. The circuit...
In this circuit, the transistors are NPN for general use and the phototransistors can be replaced by...