This circuit is from an 80's documentation, firing when the input voltage exceeds 5 V. The SCR can be the TIC106 need not have a heatsink.
This indicator for audio signals uses only 3 components. LEDs are common and the audio signal with...
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
The integrated circuit used in this configuration of the 1990 Motorola Linear Databook is not...