ANDREW SCHWARTZ:

I have a 12 channel remote that I guess you folks use for your sound boards in the R2 units, I was wondering if anyone could explain (show) how to wire a motor to it so it would rotate to the left and then hit another button to rotate right. I've had this thing for over a year and I'm ready to install it into my project that I have going right now

Actually its pretty easy to do with the board all by itself. What you need to do is wire 2 of the relays as if they were a DPDT switch to reverse the polarity of the motors. That way when you press the button and enguage one relay the motor will turn clockwise, pressing the button for the second relay will turn the motor counterclockwise.

You wont get any speed control out if it this way though.

I use this method to move the buzzsaw and gripper arms on my R7 as well as the doors on the pannels they sit in. I have limit switches installed as well. So after I open the doors I press the button and the arm extends out until it hits the limit switch. When I want the arm to retract I press the second relay button and the motor moves the arm back into the body until it hits another limit switch. Doing this with the 12 channel remote for the 2 arms uses 4 relays for the arms and 4 for the doors. And I have 4 relays to spare.

Here is a link to a good tutorial: http://www.distel.co.uk/DC_MOT_CON1.htm

JONATHAN HIGGINS:

Another way would be to add another DPDT relay, limit switches, and only need one channel on the 12ch relay board. The attached is in the files section of the yahoo group.

The lifters that Daniel provided already have the limit switches built in.

I never actually tried this setup, and don't know if anyone else has either. I just came up with it for discussion and other ideas, but it should work.

MIKE SENNA:

Get two standard relays.
Connect the motor leads to the "COM" (common) terminals. So now you have a one relay on each motor lead.
Wire the "NC" (nomally closed) together and wire them to the negative of the battery.
Wire the "NO" (normally open) together and wire them to the positive of the battery.
Wire one end of the coil on the relay to the positive of the battery (you could just put a jumper from the "NO" to the coil).
The other end of the coil goes to the ground signal provided by the switch 12.

Theory of operation is: At rest the relays are in the "NC" position. The "NC" supplies negative to both terminals of the motor. When one relay is activated, that relay supplies positve to one wire of the motor, turning it in a direction. When the other button is pressed the motor moves in the opposite direction. If both are pressed, positive is applied to both motor terminals and nothing happens. It's very similar to the dome controller, except you are using relays instead of snap switches. See here: http://astromech.net/droidwiki/index.php?title=Dome_Controller_Tutorial

CHRIS GROOTJANS:

Here's a design that works. You have to buy 2 extra relays with at least 3 switching contacts. Below the red line you have the relay board. When Ch1 is activated Relay 1 (Re1) will be activated. This way all switches marked re1 will change position. The motor will turn one way and Relay 2 (Re2) can't be activated anymore to prevent shortcutting the system. The weakness in this system is that you can't turn the motor the other way by just activating Ch2. You have to deactivate Ch1 first. If you then activate Ch2 the motor will turn the other way.

When you want a direct polarity switch when pushing the other channel the drawing would be much more complicated.

Hope this helps.

JONATHAN HIGGINS:

Still not sure why you are stuck on 2 SPDT relays when you could bypass that with a DPDT per the examples Andy and I have provided.

ANDREW SCHWARTZ:

This you can do with the relays on the board.

MIKE SENNA:

Hi Jonathan.

I am basing my answer what I understand the problem to be, making a motor turn by pressing a button and when pressing another button, it turns the other way. The circuit I proposed is not my design, but a standard way to do this using relays. The terminals will never short no matter what combination of buttons is pressed.

The one relay method you propose works great for a motor that moves one way, a fixed distance and stops, then when released the motor goes back to the starting position.

My understanding of the project may be wrong, you may know more about the project than me!

DAN SINSTEAD:

Might I suggest you check out our Model Control Devices SWITCH 8 and SWITCH 16 Function Control Systems. By using 1 of our VARI-VOLT Reversing Relays on 2 of the outputs of the decoder, you can control a motor in each direction. You can also wire up the relay to provide either the same voltage as the Function Controller is using or a different (higher or lower) voltage. All you need to supply is an alternate battery source. These were primarilly designed for scale ship model use (gun turrets, cranes, anchor winches etc) but would offer great control in your robots.

Site: http://www.modelcontrol.com