This circuit is from Dutch documentation from 1967. The circuit works with a component of the time, the BRY39, which is uncommon today.
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....