Found in an English documentation, this circuit serves as a receiver for modulated sources of ultrasound. The sensor is a ceramic capsule. Transistors are general purpose types.
Two operational are used on this triangular-rectangular oscillator suggested by Motorola in its...
Found in Linear Technology documentation from the 90s, this circuit uses an operational amplifier...
This simple two-transistor circuit used transistors from the 60s, having been found in a...