DC Motor Speed Controller


Posted on Feb 5, 2014

This circuit takes advantage of the voltage drop across bridge rectifier diodes to produce a 5-position variable voltage supply to a DC fan or other small DC motor. It is not as efficient as a switch-mode circuit but it has the virtues of simplicity and no switching hash. The four full-wave bridges are connected so that each has two pairs of serie


DC Motor Speed Controller
Click here to download the full size of the above Circuit.

s diodes in parallel, giving a voltage drop of about 1. 4V, depending on the load current. The rotary switch should have make before break  contacts which should be rated to take currents up to about an amp or so. For higher currents, higher rated bridge rectifiers and a suitably rugged rotary switch (or solenoids) will be required. If you want smaller voltage steps, you could use the commoned AC inputs on the bridge rectifiers to give intermediate steps on the speed switch.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Three-phase ac motor driver 2
Xor-gate-up-down-counter
My Arduino In Circuit Programmer
Buck Boost Voltage Converter
Wien Bridge Oscillator
Direct Conversion AM Radio
EE-8 Field Telephone
Small Footprint Square Wave Oscillator
Colorful lights loop circuit
LM1035 36 application circuit



Top