Tagged Questions

2
votes
4answers
51 views

Substitute a MOSFET in a motor controller

I'm trying to build a CoffeeBot from MAKE magazine, and I had a question about one of the components. The circuit is pretty simple; it uses an Arduino to control a gear motor via a MOSFET transistor. ...
2
votes
0answers
60 views

Matching mosfets - linear servo amplifier (AB)

I'm replacing a bunch of burnt mosfets in a linear amplifier for a brushless motor. 3 phases Each phase: 3 pairs of totem IRFP240 / IRFP9240 in parallell. (no R in series) My main concern is ...
1
vote
1answer
206 views

MOSFET relay connections to control a 3V motor

I need to turn a 1A, 3V motor on and off with a touch switch. I bought Omron 653-G3VM-61-AR and quickly smoked it. I had the battery + connected thru a 300 Ohm resistor to the touch switch (to get ...
1
vote
3answers
185 views

Transistor setup for large motor circuit

I am building a relatively simple circuit which essentially consists of two lead acid batteries rated at 12V and two motors rated at 12V. My original plan is to wire them all in series, and control ...
2
votes
1answer
395 views

Driving low-voltage H-bridge directly from MCU

I need to drive a small (3.6V, <1A) brushed motor bidirectionally with a PIC MCU. My available space is extremely limited, so I'd like to use a single 3.6V power supply for both the motor and PIC, ...
5
votes
1answer
224 views

Need help understanding and interpreting IGBT datasheets

When it comes to motor control, I understand that we have the option of using discrete MOSFETs or IGBTs. Also, there are some products in the market where 6 IGBTs are placed in one single package, ...
11
votes
4answers
2k views

How can I sense the motor's current?

I need to drive a DC motor @ 24V, 6A with a MOSFET. How can I sense the current that the motor is drawing with a microcontroller? I have to know when the motor is stalled.
8
votes
3answers
10k views

How to drive a MOSFET with an optocoupler?

What's the proper schematic for driving this MOSFET from a microcontroller pin through this or this optocoupler? The MOSFET will drive a motor @ 24V, 6A.
4
votes
1answer
184 views

Maximum switching speed of a motor

If I have a MOSFET (or a number of paralleled MOSFETs) driving a motor, what determines the maximum bandwidth (PWM frequency) at which I can excite a motor phase? Is this only a function of the total ...