This very low frequency amplifier has a gain of 1,000 and was found in a 1967 documentation. The circuit is suitable for detecting explosions, distant echoes and seismic vibrations.
This circuit is intended to trigger an alarm when the input voltage exceeds one value and to...
This circuit, found in a 1986 documentation, uses an optical sensor to count pulses and, in its...
This circuit was found in Delco documentation from 1966. The components are from that time....