What I want to do is control 5 bipolar brushed motors with one motor driver (non-simultaneous). I've got 5 DC motors that pull about 1A that I intend to use as peristaltic pumps. Only one will be running at any given time. My current tentative solution to using only one motor controller (datasheet) is to connect 5 solid state relays in series with one side of each motor and have the one ssr connected to the opposite side. This way the motors will never be on the high side of the circuit. The relay I'm considering is this one. I'm not sure this will even work as I've never dealt with solid state relays or bipolar motors. Pointers and recommendations are greatly appreciated.

 

bipolar motors indicates that they are stepper motors. Bushed means they are standard DC motors (2-wire). Which are they?

Also, how will you be turning the motor controller on/off? (Microcontroller?)

 

And, you can buy 5 of these chips already mounted on a PCB for $22 total. Why not a separate board for each motor?

https://www.pololu.com/product/2136

Or, 3 of these dual motor drivers for 4.50 each or $16 total.

https://www.pololu.com/product/2135

 

Are you really going to need bi-directional control?
Typical peristaltic pumps are set for one direction only..
And assuming a DC motor you don't need a driver at all.. Unless you need speed/ml control or something..

 

Those are Sharp Triac SSR's so they operate with AC not DC motor control?
Max.

 

Those are Sharp Triac SSR's so they operate with AC not DC motor control?
Max.

Gee.. Only the second sentence of the datasheet..

These devices are ideally suited for controlling high voltage AC loads

 

Thanks GopherT! I have a tendency to overlook the obvious, yes it will be controlled from an arduino. Also, since i'm a student I think I can get the controllers for free as a sample from TI!

Mcgyvr: When peristaltic pumps are used for things such as titrations and other such things, the motors should be able to go backwards to prevent drips from the line and to minimize line exposure to caustic chemicals (in my case).

I understand that they are suited for AC applications, but I wanted to have current flow in both directions. I was unsure that a triac would be able to do what I wanted, but I think it can operate like a bidirectional switch for dc current if the gate can easily be made to go from positive to negative.

 

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Thanks GopherT! I have a tendency to overlook the obvious, yes it will be controlled from an arduino. Also, since i'm a student I think I can get the controllers for free as a sample from TI!

Mcgyvr: When peristaltic pumps are used for things such as titrations and other such things, the motors should be able to go backwards to prevent drips from the line and to minimize line exposure to caustic chemicals (in my case).

I understand that they are suited for AC applications, but I wanted to have current flow in both directions. I was unsure that a triac would be able to do what I wanted, but I think it can operate like a bidirectional switch for dc current if the gate can easily be made to go from positive to negative.

may be free but, they are also quite small for DIY boards unless you are using the photosensitive PCBs. On the other hand, you will spend at least $5 per board to DIY.

 

I'll be soldering them to a custom made pcb

 

I understand that they are suited for AC applications, but I wanted to have current flow in both directions. I was unsure that a triac would be able to do what I wanted, but I think it can operate like a bidirectional switch for dc current if the gate can easily be made to go from positive to negative.

Not sure if you are hoping for alternate quadrant switching but for starters the firing voltage is unidirectional due to the input being an IRED of fixed polarity.
There are other methods of direction control that may be suitable, especially if you want full on in either direction?
Max.

 

I think the cheapest solution to this problem is to simply get 5 controllers. I'm still interested in hearing about the other methods of direction control though.

 

DC drivers are usually bidirectional. You only have to turn on the relay and demand + or - direction from the controller. Also you'll find a standard relay to be cheaper than a solid state relay. Assuming your controller can reverse, the relay acts as a simple on/off switch.