Tag Archives: Power Control
Pulse Width (PWM) Controller Circuit

A LM3900 quad operational amplifier can be used to build a pulse width (PWM) controller. The LM3900 was chosen because it only need single supply voltage of 4 to 30 V. This circuit can give 100 percent pulse-width control. A1 … Continue reading
Two Methods for Push Button Controlled Power Switch

On these two following circuits, we can latch on the SCR (and thereby the lamp) by momentarily closing S1, thereby feeding gate drive to the SC via R1. The gate is tied to the cathode via R2 to improve circuit … Continue reading
Separate ON-OFF Touch Switch

Providing a touch switch can be a cool way to make your circuit looks sophisticated. Moreover, providing separate touch pad for “on” and “off” function improve the safety, since touching one function doesn’t trigger opposite action to what we expect … Continue reading
Remote On-Off Switch through Small Transformer

This is a remote on-off switch circuit. With this circuit, we can take the benefit of using small switch to control larger AC current from high power devices. Safer operation is the other benefit, since this circuit is control the … Continue reading