This touch switch uses components that have easy-to-obtain current equivalents. The power supply must be isolated and the cable to the sensor must be short.
This well-designed bistable configuration is for educational purposes. We found it in the...
This low power bass booster is from the 1977 National Semiconductor Audio Handbook. The circuit is...
This circuit, well known to our readers, only has a slightly different schematic representation, as it was...