I will buy a pololu 2814 mosfet. But I have some questions. I want to drive a DC motor with push button 2814. DC Motor runs with 7.4V 6.5A current(I tested it with multimeter). I want to control with Arduino. I understand that can use sw and gnd pins as on- off push button. Is it true?
So if I give to sw a 5v voltage, push button is on state ?Or what do I get it? I plan to use with digitalwrite command
Also I will use it for my airsoft gun as a trigger.
I need Arduino for timing operations. Also what is caution points about using errors?
The SW pins are meant to be connected to a mechanical switch; you should not connect them to your Arduino. You can use the ON pin to turn the switch on with a microcontroller like an Arduino.
In general, inductive loads can produce voltage spikes with MOSFET switches like this. You might look around for a tutorial that discusses adding a flyback diode to inductive loads like motors. Alternatively, you could use a motor driver (which generally have components that serve as built in flyback diodes) instead of the pushbutton power switch. You can find our motor drivers here:
Please let me know if you have any additional questions.
Actually I didn’t use mosfet so far. And I had liked VHN5019 DC motor driver ,but I afraid of it. I think It will be able to burn my motor. Because It gives continuous 12A. Or I have lack of knowledge.Pololu infotmation is that… “This carrier board for ST’s VNH5019 motor driver IC operates from 5.5 to 24 V and can deliver a continuous 12 A (30 A peak)”…You know that My motor’stall current is about 6.5A or 7A . According to you, can It burn my motor ? or is It convenient my motor ?
Also …Thank a lot for your information sharing and help.
At stall (when the rotor of the motor is not spinning), brushed DC motors generally behave like a resistive load (so the stall current is proportional to the supply voltage). Motor drivers like the VNH5019 can disconnect the motor from the supply to decrease the current from the stall current. Current is not pushed through the motor by the driver; the driver just supplies as much current as the motor draws. Increasing the maximum current the motor draws would require increasing the supply voltage. Generally, motor drivers do not do that.
The sentence you quoted means that if you have a motor that tries to draw more than 12A for too long, the VNH5019 might overheat (this driver turns itself off when that occurs). If you have a motor that tries to draw more than 30A, the VNH5019 will detect that and quickly turn itself off briefly to limit the current.
In general, it seems like the VNH5019 can handle enough current to work with your motor (we generally recommend using a driver that can handle the stall current of the motor continuously). Also, you should be aware that a mechanical load that stalls the rotor (prevents it from spinning) can cause the motor to draw the stall current, that drawing the stall current can damage the motor, and that the VNH5019 will not prevent the motor you mentioned from drawing the stall current in that situation. Generally, you should avoid stalling the rotor to prevent that.