Tachless-motor-speed-controller


Posted on May 25, 2012

This circuit is particularly applicable to digitally-controlled systems in robotic and X-Y positioning applications. By functioning from the 5-V logic supply, it eliminates additional motor-drive supplies. The tachless feedback saves additional space and cost. The circuit senses the motor`s back EMF to determine its speed. The difference between the speed and a set point is used to close a sampled loop around the motor. Al generates a pulse train.


Tachless-motor-speed-controller
Click here to download the full size of the above Circuit.

When Al"s output is high, Ql is biased, and Q3 drives the motor"s ungrounded terminal. When Al decreases, Q3 turns off and the motor"s back EMF appears after the inductive flyback ceases. During this period, Sl"s input is turned on, and the 0.047-I"F capacitor acquires the back EMF"s value. A2 compares this value with the set point and the amplified difference (trace D) changes Al "s duty cycle, controlling the motor speed.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

BFO Circuit
Temperature-measuring-add-on-for-dmm-digital-voltmeter
General-Purpose 5W Audio Amplifier With Ac Power Supply
2Mhz Frequency Counter Circuit
LCD monitor Switched Mode Power Supply
200mW High Quality FM Transmitter With TX-200
geiger power supply circuit
digital switching system
Basic Tilt Sensor Tutorial Circuit
Circuit power audio amplifier TDA2040 20 watts integrate circuit with pcb and power supply circuit
CXA1019S FM AM radio circuit diagram



Top