درایو موتورها

[javad naderi]

12V DC motor speed controller





A very simple encoder circuit for a dc motor can be constructed using this circuit diagram . As you can see in the circuit diagram , the system shown consists of the HA-2542, a small 12-Vdc motor, and a position encoder. During operation, the encoder causes a series of ''constant-width" pulses to charge CI. The integrated pulses develop a reference voltage, which is proporţional to motor speed and is applied to the inverting input of HA-2542, The noninverting input is held at a constant voltage, which represents the desired motor speed. A difference between these two inputs will send a corrected drive signal to the motor, which completes the speed control system loop.
As you can see the circuit requires few external components , but because of the encoder wheel it has a limitations of use .


If you put a pulley under the encoder wheel you can command the speed of other device , by connecting the (motor and other device ) using a belt .

[javad naderi]

3A, 55V H-Bridge

Features Delivers up to 3A continuous output
Operates at supply voltages up to 55V
Low RDS(ON) typically 0.33Ω per switch at 3A
TTL and CMOS compatible inputs
No “shoot-through” current
Thermal warning flag output at 145°C
Thermal shutdown (outputs off) at 170°C
Internal clamp diodes
Shorted load protection
Internal charge pump with external bootstrap capability

Description
The LMD18200 is a 3A H-Bridge designed for motion control applications. The device is built using a multi-technology process which combines bipolar and CMOS control circuitry with DMOS power devices on the same monolithic structure. Ideal for driving DC and stepper motors; the LMD18200 accommodates peak output currents up to 6A. An innovative circuit which facilitates low-loss sensing of the output current has been implemented.


Applications
DC and stepper motor drives
Position and velocity servomechanisms
Factory automation robots
Numerically controlled machinery
Computer printers and plotters

[javad naderi]

SN754410 Dual H-Bridge:

The next step was to connect the proper wires from the stepper motor to the Dual H-Bridge chip. The next figure shows how this was done. Each coil acts as its own motor and is connected to the h-bridge pins (3 and 6, and 14 and 11) of the SN754410. Pin 8 of the SN754410 is connected to the motor's voltage supply (usually +12VDC). It is recommended to build the circuit for the BX-24 and the SN754410 on the same board and put the power supply for the motor on a separate board. If you do this, remember to connect ground from the motor supply board to the board housing the BX and dual H-bridge.