Found in an Electronic Design from the 80's, this circuit uses components from that time. He has outputs for activating 8 solenoids from a microcontroller.
We found this circuit in the Linear Applications Handbook published by National Semiconductor in...
In a September 1992 Radio Electronics article, we found this basic 555 circuit used to generate fixed...
In the figure we have a simple way to have a peak bargraph indicator. The amplifier is of the...