Back emf motor speed control


Posted on May 31, 2012

The use of power MOSFETs allows a direct interface between logic and motor power, which permits circuit simplicity as well as high efficiency. This speed control circuit can be packaged on a 22-pin, double-sided, 3.5 4-in. pc board. A 12 V control supply and a TRW BL11, 30 V motor are used; with minor changes other motor and control voltages can be accommodated. For example, a single 24 V rail could supply both control and motor voltages. Motor and control voltages are kept separate here because CMOS logic is used to start, stop, reverse and oscillate the motor with a variable delay between motor reversals.


Back emf motor speed control
Click here to download the full size of the above Circuit.

Motor speed is established by potentiometer R2, which applies a corresponding dc voltage to the + input of comparator Ul, whose output is then applied to TMOS device MTP8P08 (Ql). Zener diode Dl limits the drive to Ql. The output of Ql drives the permanent magnet motor.Back emf is obtained from the motor via the network consisting of R8, R9, RIO, C2, C3 and D3; it is applied to—input of comparator Ul.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

12 VOLT GEL CELL CHARGER
High Voltage High Current Power Supply
Optical communication system
Audio operated relay
Metal Detector
the water level control system design of the one-chip computer
Drive A Relay Using A 1-Wire Addressable Switch
simple circuit mini bicycle bel
Sensor
microcontroller complete code midi emulated ps 2 keyboard
Automatic Light Controller Using 7806



Top