This TTL shield with high level logic is from the LM111's own 80's manual. The integrated circuit is no longer easily found, but the circuit can be adapted to use modern equivalent operational amplifiers.
May 2017 - Mouser Electronics already has for sale the new Littelfuse SP2555NUTG diode arrays for...
To control direct current loads, under voltages between 12 and 200 V, and currents up to 3 A, we...
The zener diode determines the triggering of the circuit and R3 must be a resistor that will be...