This circuit was found in a 90s Silicon Chip documentation. The current of the transformer is 1 A maximum, a value given by the integrated circuits used.
This experimental amplifier was found in the 1960 Mullard transistor reference manual. The...
This circuit from Motorola is from 1968, appearing elsewhere on this site. The transistors admit...
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...