This circuit can keep a set of lamps on for up to 1 minute, time given by C2 and R2 that can be changed. The load depends on the relay. The circuit is old, from 1988 documentation, but totally viable today.
This circuit is indicated to power TTL circuits with current drains up to 500 mA. The transistor...
This is a typical RF oscillator configuration found in a 1980s documentation. The frequency...
This circuit was obtained in an old documentation, making use of an operational amplifier of the...