This power control for powers up to about 10 W uses wire potentiometers in an arrangement that allows to maintain the impedance. The circuit is from old European documentation.
This high-power amplifier that comes close to 400 W peak uses unusual high-power transistors...
In this circuit we have the way to obtain a pseudo sequential effect of LEDs using 3 FETs. The...
This amplified circuit was found in a magazine for radio amateurs 73 of the 90s. The circuit uses an...