Forum Diagram: motor

Tuesday, November 4, 2014

Small DC Motor Control Using PWM

Small DC motors are efficiently controlled using pulse-width modulation (PWM) method. The circuit described here is built around an LM324 low-power quad-operational amplifier. Of the four op-amps (operational amplifiers) available in this IC, two are used for triangular wave generator and one for comparator. Op-amp N2 generates a 1.6kHz square wave, while op-amp N1 is configured as an integrator. The square wave output of N2 at its pin 14 is fed to the inverting input (pin 2) of N1 through resistor R1. As N1 is configured as an integrator, it outputs a triangular wave of the same frequency as the square wave. The triangular wave is fed to pin 5 of op-amp N3, which is configured as a comparator.

Small DC Motor Control Circuit Diagram :

The reference voltage at pin 6 of the comparator is fixed through the potential divider arrangement formed by potmeter VR1 and resistors R4 and R5. It can be set from –6V (lowermost position of VR1) to +6V (uppermost position of VR1).

The triangular wave applied at pin 5 of N3 is compared with the reference voltage at its pin 6. The output at pin 7 is about +12V when the voltage at pin 5 is greater than the voltage at pin 6. Similarly, the output at pin 7 is about -12V when the voltage at pin 5 is lower than the voltage at pin 6.

The output from comparator N3 is the gate voltage for n-channel MOSFET (T1). T1 switches on when the gate voltage is positive and switches off when the gate voltage is negative. Setting of the reference voltage therefore controls the pulse-width of the motor. When T1 is switched on for a longer period, the pulse width will be wider, which means more average DC component and faster speed of the motor. Speed will be low when the pulse width is small. Thus potmeter VR1 controls the speed of the motor.

Assemble the circuit on a general-purpose PCB and enclose in a suitable cabinet. The circuit requires ±12V power supply for its working. It can also be modified to control the speed of a 6V or 24V DC motor.

Ceiling Fan Regulator Motor Speed Control Wiring diagram Schematic

This is a simple ceiling fan regulator schema diagram. It is used to control the speed of a ceiling fan. In the other words it is an AC motor speed controller schema, as because its control the speed of a AC motor(Ceiling Fan). This ceiling fan regulator schema built with few numbers of parts. The schema mainly based on Z0607 TRIAC. This is a low power AC semiconductor device. Generally which is used to controlling speed of low power ac motor speed.

Circuit Diagram of Ceiling Fan Regulator :

In this ceiling fan regulator schema, R1=500KΩ is a variable resistor that is used to adjust the fan speed. Capacitor C1 2A104J is a Polyester film capacitor.

Pin Diagram of TRIAC(T1)- Z0607:

Fig: Z0607-TRIAC Pin diagram

Pin Diagram of Variable Resistor R1:

Fig: Pin Diagram of Variable Resistor

Parts List Ceiling Fan Motor Speed Controller schema:

T1 = Z0607 -TRIAC
D1 = DB3 C312 -DIAC
R1 = 500KΩ -Variable Resistor
R2 = 37KΩ -Resistor
C1 = 2A104J -Polyester film capacitor.
M1 = Single Phase AC Motor (Ceiling Fan)-220V,50Hz

Source

DC motor driver with H Bridge IC L293D

Making a DC motor driver with H-Bridge technique can use IC L293D as in the article "DC Motor Driver H-Bridge L293 (2 Motor DC)"is. DC motor driver L293D can be used to control the DC motor 2 pieces at once. DC Motor Driver L293D can be used to control a DC motor continuously or with a PWM technique. Dc motor driver circuit in the article "DC Motor Driver H-Bridge L293 (2 Motor DC)" only use IC L293D only. For more details see the following figure.

Working system of DC motor driver L293D is to provide control signals in the form of logic or pulse to the input lines 1A - 1B for DC motor control M1 and the input 2A - 2B for the control of DC motor M2 with the following conditions:

Input A Input B Motor DC
0 0 Motor silent
1 0 motor rotates counterclockwise
0 1 Motor berputer clockwise
1 1 Motor silent
Description: Enable Input given a logic 1 to obtain such data in the table above.

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