Obtained from a 1969 documentation, this circuit can operate at frequencies up to 500 Hz, counting up to 999. The circuit makes use of neon lamps of the time.
This circuit was found in the Analog Devices component manual, providing a negative voltage of 2.5 V...
The circuit is from an 80's publication, but the components are current, only special type diodes...
TR1 must be mounted on a heatsink in this circuit. Voltage output is 8.6 V but this value can be...