This is the circuit of the commercial Japanese megaphone of the 60s model DM-218. The circuit uses a compression speaker (horn) and is powered by 4 large batteries. The output power is 2 W.
This control for motors up to 1 A was found in a Siliconix documentation using its own component....
This filter rejects the hum of 60 Hz from power grid, being placed between the signal source and...
In the figure we have an interface using an optical coupler and the comparator LM339 or any...