This circuit is from a 1968 publication. Here we have several types of resistive sensors with individual adjustments triggering a single SCR. Power depends on the type of sound device to be triggered.
The circuit presented is from the National Semiconductor's Linear Applications Handbook of 1994. We...
This is one of the many versions we have of a 12 V power supply with the 7812. We found it in the...
This fader or fader was found in a 90s Popular Electronics. The circuit uses transistors that are...