We found this circuit in a 1991s PE Hobbyst Handbook. The circuit fires 10 LEDs that can control incandescent lamps according to their maximum current.
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...