We found this circuit in a 1980s Motorola documentation. The circuit makes use of common operating and the voltage depends on the used type. The components are for a frequency of 500 Hz.
This circuit was found in a 1965 Radio Shack documentation. The transistors are from that time....
This circuit was found in documentation from Analog Devices. The circuit is based on an AD795 and...
This circuit was obtained in Radio Electronics from the 90s. The integrated circuit is uncommon...