Motor brakes

[jamesrobinson]

Hi I’m building a bot and have some ? How do I properly conect the 2x32A sabertooth speed controler to the brakes in a wheelchair motor. Also can I conect two speed controlers to the same receiver . One more thing if I’m use in it out side should my electronics be in a air tight case… The two controlers I have are 2x12a, 2x32a sabertooth …in the box u sent me there are two 10w resistors not sure wher they should go

[cbenson]

How do I properly connect the 2x32A sabertooth speed controler to the brakes in a wheelchair motor.

robotshop.com/media/files/pd … asheet.pdf

In the user guide, there is a section “Auxiliary inputs and outputs”:
Sabertooth 2x32 has two additional 8A power outputs, which can be set up to operate electromagnetic brakes on motors, act as a voltage clamp to protect power supplies, or power other medium duty loads. Sabertooth 2x32 also has extra signal inputs and extra serial ports which enable better control options. Also, under “Overview”: Power Outputs: These connect to voltage clamp resistors, electromagnetic brakes, field windings, or other moderate power loads. 8A max current per channel.
There is also a section “Brakes” under “Power Outputs”.

Also can I conect two speed controlers to the same receiver .

Certainly.

One more thing if I’m use in it out side should my electronics be in a air tight case… The two controlers I have are 2x12a, 2x32a sabertooth …in the box u sent me there are two 10w resistors not sure wher they should go.

Read through the user guide and if your application makes no use of them, then they are not needed. The controllers should not be exposed to rain / snow / high humidity, so it’s up to you to determine how best to seal them.

[jamesrobinson]

So for the electric brakes one wire to p1 or p2 on the sabertooth and one wire to ground

[cbenson]

Brakes
The power outputs can also be used to operate electromagnetic brakes. Systems such as wheelchairs often have brakes to prevent rolling away when power is removed. Brakes are also used in CNC machines and automation to hold alignment when power is removed or reduce power consumption. In brakes mode, the brakes automatically disengage when motion is commanded, and engage when the motor stops. When using Brakes mode, the P1 output is linked to the M1 motor output, and the P2 output is linked to the
M2 motor output. With the brake timing changed, brakes mode can also be used to control the field in a shunt wound or separately excited motor. Brakes mode must be selected and configured from the Power Outputs tab using the DEScribe software.

If you are using the power outputs for electromagnetic brakes, the positive side of both brakes connect to the B+ terminal. The negative side of the M1 brake connects to P1, and the negative side of the M2 brake connects to P2. Remember that to use brakes you must set the power outputs to brakes mode using the DEScribe PC software.

[jamesrobinson]

I was reading some things and in order to use the brakes on sabertooth I have to program it on DEScribe PC … That sucks … So negative from motor brake goes to p1 and positive from brake goes to batt … Found out what the resistors are for , the driver comes with the p1 and p2 programmed as regenerative drives so p1 goes to 10w resistor then to the B+… Realy never done this befor is it easy to program sabertooth with DEScribe PC in order to use p1 and p2 as brakes …