Any high-gain Darlington transistor can be used on this touch circuit. The load can be formed by LEDs and the power supply isolated from the power grid.
Suggested by Burr Brown in 1969 documentation, this circuit makes use of an integrated component...
This bass and treble control only attenuates the corresponding signals, requiring further...
Found in an Electronic Design from the 80's, this circuit monitors the charge of a 12 V battery....