This circuit, suggested by an Electronics World of 1969, keeps a blinking LED for a while when a power outage occurs. Time depends on capacitor C1.
This preamplifier is recommended by Sanyo and is based on its LA3160 integrated circuit. The...
This reinforcing stages from a 1960s documentation. No information is given about the transformer...
This circuit can use any comparator or even an operational amplifier. We can use the LM339 and the...