Drop Fractional Voltage to Absolute Zero to Disable H-Bridge

Thread Starter

MyTPioneer

Joined Dec 18, 2015
12
I'm trying to wire up an XBOX 360 controller to an H-Bridge, that is connected to a 12v DC motor. The output on the 360 controller is about .002v when idle, and it's causing the H-Bridge to enable the 12v DC motor at this point.

Is there anything I can do to prevent the .002v from reaching the H-Bridge?

Thank you for any suggestions.

DC
 

crutschow

Joined Mar 14, 2008
34,285
That seems to be a very sensitive H-Bridge.
Try placing a diode in series with the XBox output (anode to output) with a 10kΩ resistor from the cathode to ground.
Drive the H-bridge from this diode-resistor junction.
 

Thread Starter

MyTPioneer

Joined Dec 18, 2015
12
I tried the setup recommended by Crutschow and something is still not right. When I put a multi-meter between the cathode side of the connection and the black wire from the 360 controller, it now reads zero. But when I make the connection to the H-Bridge, the motor still runs and the resistor becomes really hot.

I'm sure I don't have things set up correctly.

Here is my setup:
The 360 controller has a black and red wire coming out of it that used to run to the old shaker motor. I have the black wire going to number 5 (GND). I also have the ground from the 12v power supply I am using going into number 5. The red wire from the 360 controller is connected to Pin 9 (IN 2). The two wires from the 12v motor are connected to 1 & 2. All jumpers are in place. Below is a reference photo to the H-Bridge.

Any thoughts on where I'm going wrong?


  1. DC motor 1 "+" or stepper motor A+
  2. DC motor 1 "-" or stepper motor A-
  3. 12V jumper - remove this if using a supply voltage greater than 12V DC. This enables power to the onboard 5V regulator
  4. Connect your motor supply voltage here, maximum of 35V DC. Remove 12V jumper if >12V DC
  5. GND
  6. 5V output if 12V jumper in place, ideal for powering your Arduino (etc)
  7. DC motor 1 enable jumper. Leave this in place when using a stepper motor. Connect to PWM output for DC motor speed control.
  8. IN1
  9. IN2
  10. IN3
  11. IN4
  12. DC motor 2 enable jumper. Leave this in place when using a stepper motor. Connect to PWM output for DC motor speed control.
  13. DC motor 2 "+" or stepper motor B+
  14. DC motor 2 "-" or stepper motor B-
 

tracecom

Joined Apr 16, 2010
3,944
Why did you connect red wire to In2? Why not In1? I am not saying it's wrong; I just wonder what your reasoning was.

I really don't understand why you are using an H-bridge. Are you reversing the motor?
 

Thread Starter

MyTPioneer

Joined Dec 18, 2015
12
I used Pin 2 because I recycled a connector that I had and it only had a wire coming out of 2-4, so I started with 2. I used an H-Bridge because I had one laying around and thought that was the way to go. I'm open to other suggestions to power a 12v motor using the 1.8v signal that comes out of the 360 controller.

Thank you for all of your input.
 

Thread Starter

MyTPioneer

Joined Dec 18, 2015
12
Correct. One direction is all I need and either way is fine. My 12v motor is taking the place of the much smaller original shaker motor.
 

Thread Starter

MyTPioneer

Joined Dec 18, 2015
12
I went with a SPST - 5VDC Reed Relay from Radio Shack that I had laying around and it is working like a charm.

Thanks a ton for the suggestion and guidance Tracecom.
 

Tonyr1084

Joined Sep 24, 2015
7,853
Here's a schematic of what I had in mind for a solid state switch.

http://www.neufeld.newton.ks.us/files/electronics/mosfet-motor/MOSFET-motor-driver.png
Good circuit - and possibly more reliable than a 5VDC Reed switch relay. But if you use the electronic form I'd recommend a snubber diode across the motor with the anode toward the supply. But if you're using the reed switch then you don't need the diode, there's no electronics to be harmed.

[edit] - If you're using a relay then I'm hoping you have a snubber diode across the relay to prevent flyback from damaging your controlling source.
 

crutschow

Joined Mar 14, 2008
34,285
Good circuit - and possibly more reliable than a 5VDC Reed switch relay. But if you use the electronic form I'd recommend a snubber diode across the motor with the anode toward the supply. But if you're using the reed switch then you don't need the diode, there's no electronics to be harmed. ..............
Not generally true.
Relay contacts (especially the small contacts on a reed relay) may also need a snubber diode when driving an inductive/motor load to prevent contact burning and welding (since without a snubber the inductive energy will be dissipated in an arc across the contacts as they open).
 

Tonyr1084

Joined Sep 24, 2015
7,853
Relay contacts (especially the small contacts on a reed relay) may also need a snubber diode when driving an inductive/motor load to prevent contact burning and welding (since without a snubber the inductive energy will be dissipated in an arc across the contacts as they open).
Good point. I sort of forgot about that.
 
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