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.
This circuit was found in an English documentation from the 90's. Equivalent components such as...
This circuit was found in an Electronics Now of the 80s applying to NiCad batteries of the time....
The pulses applied to input C of the SAA1027 integrated circuit determine the engine speed. Each...