What transistor do i need?

Other Hardware General Electronics
1

i have an external power supply that give me 12V 1.5A, what transistor can i use?, i am trying to turn on a motor.

Thanks.

2

We need a little more information please. What is the voltage/current rating of your motor. What will turn the transistor on. If it is an Arduino, is it the 5V or 3.3V version. We need to understand what you need to do before we can advise you. otherwise we are just guessing.

3

OK,

as promacjoe2 already wrote, there's not a lot of info to give you advice. But starting from your 12V/1.5A power supply I assume that you'll run the motor with 12V and that you won't need more than these 1.5A.

First choice is bipolar vs. MOSFET and here we clearly decide on a MOSFET transistor. You'll want to switch that transistor fully on with the voltages from a port output. So let's go with an N-channel enhancement MOSFET. Here the motor would be connected between the drain of the transistor and the 12V supply.

Decision parameters:

  • Maximum Drain/Source voltage.
    12V is not enough. A motor is a highly inductive load. That means that it will create high voltage spikes when turned off. Without knowing the motor parameters, I'd go for a transistor with high capabilities.

  • Maximum Drain current.
    At least the 1.5A, with a little saftey margin.

  • The transistor should have a built-in D/S reverse polarity diode.

  • Gate threshold voltage.
    Must be lower than the supply voltage of the Arduino, because that will be the control voltage on the port pin which controls the transistor.

  • Low On resistance (RDS(on)).
    Something far below 1 Ohm.

Looking through my collection of datasheets I find an MTP10N10EL from OnSemi:
Max current:10 A
Max D/S voltage: 100 V
RDS(on): 0.22 Ohm
Gate threshold voltage: 2 V

The charts don't look too good for a 3.3V operation. But with only 1.5A or less current the power dissipation shouldn't be too high.
Try to check what's available to you and read the datasheets.

I have a little project where I switch with a P-Channel MOSFET (Load connected between drain and GND). But you'd need a second transistor (N-Channel) and a pullup resistor to make that work.

HTH,
Christian

4

I want to turn on a motor with 12v and 1.5A, i am usin an Arduino uno

5

Can you work with an SMD part?