This circuit found in a 90s Popular Electronics, triggers a huge array of LEDs from the sounds captured by a microphone, thus generating visual effects.
This circuit is from an old documentation of Radio Shack from the 70s. The transistor should...
When the power is cut off, this circuit keeps the flashlight on for a while, allowing it to be...
This circuit was obtained in an old Popular Electronics. It makes use of quite common components....