Very strong audio spikes in a headset can damage the ear. This circuit, from a 90s Popular Electronics cuts them, being originally indicated to operate with an integrated amplifier of the time.
The figure shows how to control the blinking of a 5 V blinking LED with an LDR. The LED only...
Suggested by Maxim in documentation from the 90s, this circuit has its response curve given next to...
This circuit is from a 1965 General Electric publication. It uses a thermistor to fire a reed...