This current boosting circuit uses an op-amp and 3 transistors. The current depends on Q1. The circuit is from the 1995 Encyclopedia of Electronic Circuits Volume 5.
With the coded activation of the relays, it is possible to control which of the 16 outputs...
The integrated circuit used in this application is not very common. Transistors and resistors...
This simple circuit makes use of neon lamps to indicate the voltage of a power grid. The lamps are...