This circuit from a Radio Electronics from December 1974 was used in color televisions of the time. It serves as a reference for restoration work. The circuit is of the ultrasonic type.
Found in a 1964 magazine, this is a small headphone amplifier from 500 ohms to 10 k ohms (magnetic...
This key is turned off by a touch sensor. The time it remains active depends on capacitor Cx. The...
This circuit generates sinusoidal and cosine signals of 2 kHz given basically by the values of C1...