This circuit is used to turn on the headlights when it gets dark. The circuit is from an Electronics Now magazine from October 1998. The power transistor must be equipped with a heatsink.
The figure shows how to implement an alarm buzzer in an LM3914 to warn about crossing the scale...
This circuit can act as a shield being controlled by a microcontroller by pin 1 or 2. The...
This circuit was obtained from a 1980's QST magazine. The circuit can generate 1 to 15 MHz signals...