Plug-in speed control for tools or appliances


Posted on Jan 5, 2013

Most standard household appliances and portable hand tools can be adapted to variable -speed operation by use of this simple half-wave SCR phase control. It can be used as the speed control unit for the following typical loads pro-videe they use series universal (brush type) motors. During the positive half cycle of the supply voltage, the arm on potentiometer R2 taps off a traction of the sine wave supply voltage and compares it with the counter emf of the motor through the gate of the SCR


Plug-in speed control for tools or appliances
Click here to download the full size of the above Circuit.

When the pot voltage rises above the armature voltage, current flows through CRI into the gate of the SCR, triggering it, and thus applying the remainder of that half cycle supply voltage to the motor. The speed at which the motor operates can be selected by R2. Stable operation is possible over approximately a 3-to-l speed range.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

FM reciever with classic TDA7000
Rotating Message board using PIC12F629
30 LED audio frequency analyzer
Christmas Star with LEDs
15V And 5V Car Battery Supply
The Design of Car Audio Power Amplifier
PIC 16F88 Digital Thermometer Light Meter and resistance ohm meter
6V6 6J5 Class A Vacuum Tube (Valve) Amplifier Circuit
Stereo FM transmitter using BA1404
Vehicle Interior Lighting With Switch-Off Delay
Low Supply Rail Detection
555 capacitance frequency transistor-line detector
Incandescent Yeonsu electronic controller 3



Top