We found this circuit in an English publication from 1969. It shows how we can implement a bridge null detector using common general purpose transistors.
This circuit reproduces the dial noise in a small speaker. The transistor can be a general-purpose type....
We found this circuit in an 80's schematic. The circuit uses LEDs in series with zeners to...
This circuit turns off after a time given by capacitor C1. This component can have from 1 to 1,000...