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 circuit compensates for losses in pre-amplified audio or tone control stages. The circuit can use...
Found in the Encyclopedia of Electronic Circuits volume 5 from 1995, this circuit uses a...
This is a bridge for the measurement of low value resistances and high values too. The circuit...