P1 on this Radio Shack circuit is a 6 V lamp with current up to 500 mA depending on Q2. The frequency is given by C1 which can have a modern standard value such as 3.3 uF or even 4.7 uF.
This high pass filter was found in the February 1996 Electronics Now magazine. The circuit...
Found in a 90s 303 Circuits, this circuit uses the KTY10 sensor, widely used at the time. | Clique na...
Found in a 90s Popular Electronics, this circuit keeps an LED on when a phone is in use. Can be...