We found this circuit in a 1965 Electronic Design. Transistors are still common but admit equivalents for some of them. The circuit drains a current of only 4 mA.
This doorbell or buzzer as announced in a 1990s US publication uses an operational amplifier that admits...
This circuit is powered by only 3 V and can flash white LEDs from 3.2 to 3.6 V, as it includes a voltage...
The load on this amplifier is 8-ohm. We found the circuit in a 1972 Motorola amplifier manual. The...