This simple injector and signal follower employs a high impedance headset. Transistors can be of general use. The circuit is from old American documentation.
This circuit shows how to use the TTL IC 7790 to divide a square TTL signal by 7. Duty cycle is...
The AC125 transistor is an ancient germanium type widely used in audio stages as a preamplifier. In the...
Found in a 90s Popular Electronics, it serves both TTL and CMOS logic. The injector can provide 10...