In a September 1992 Radio Electronics article, we found this basic 555 circuit used to generate fixed times. Capacitor C1 and resistor R1 determine the time. The circuit drives an LED.
Linear Technology's LT213 circuit, which suggests this application in 90s documentation, is not...
This circuit is more elaborate than the previous one, employing an integrated amplifier circuit of the...
This circuit was found in a PE Hobbyst Handbook from 1992. The second oscillator is a VFO. The...