# Modular Controller



## TheSGC (Nov 15, 2007)

Someone posted in another thread an idea for a controller that was like a modular system. So I got to thinking and came up with an idea, microprocessor based, that consists of about $35 of parts for each unit, and they would be up to 156 volt and 60 AMPs continuous. 

The basic idea is that each unit can be used on their own, say for a go cart or bike, but then can be connected in series for a high powered use. When connected in series, the first unit will be the main brain power, and the other microprocessors will just watch and report the current back to the primary unit. 

I am working on a schematic and I have enough components to make three or four 48 volt prototypes so that will be a nice project my winter break. The design will use a Hall Effect Current sensor, 250 volt MOSFETS and a PIC18F2480 processor.


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## ClintK (Apr 27, 2008)

TheSGC said:


> Someone posted in another thread an idea for a controller that was like a modular system. So I got to thinking and came up with an idea, microprocessor based, that consists of about $35 of parts for each unit, and they would be up to 156 volt and 60 AMPs continuous.
> 
> The basic idea is that each unit can be used on their own, say for a go cart or bike, but then can be connected in series for a high powered use. When connected in series, the first unit will be the main brain power, and the other microprocessors will just watch and report the current back to the primary unit.
> 
> I am working on a schematic and I have enough components to make three or four 48 volt prototypes so that will be a nice project my winter break. The design will use a Hall Effect Current sensor, 250 volt MOSFETS and a PIC18F2480 processor.


I don't know the feasibility, but keep us posted.  By the way, did you stop development on the original microprocessor controller for your EV? Or has it just transformed into this new idea?


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## TheSGC (Nov 15, 2007)

ClintK said:


> I don't know the feasibility, but keep us posted.  By the way, did you stop development on the original microprocessor controller for your EV? Or has it just transformed into this new idea?


I hope to figure out the feasibility with these tests.

As for my original microprocessor controller I ran into a massive road block: I need an oscilloscope. I have the darn thing on the protoboard, but I need readouts on the gate driver to finalize the connection from the UCC37322 to the CM600HA IGBT. I discovered the Supply Room at college and got a load of parts and this week I am going to ask about borrowing one of the many older Oscilloscopes that are collecting dust in there. I have most of the electronic parts for it, I just need the darn scope, some buss bars and some really large caps. 

The smaller modular controller makes it much easier to prototype and test because of the smaller parts to work with, like MOSFETS instead of IGBT modules.


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## Beyonder (Sep 18, 2008)

I wouldn't think feasibility would be a problem here. Also, I may be out in left field but why wouldn't you build a small PWM controller with a 555 timer ( mentioned on another post ) and mosfets, And use a plug in system similar to a USB connector,etc? I dont know a lot about electronics but increasing power would be like connecting batteries wouldn't it?


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## TheSGC (Nov 15, 2007)

Beyonder said:


> I wouldn't think feasibility would be a problem here. Also, I may be out in left field but why wouldn't you build a small PWM controller with a 555 timer ( mentioned on another post ) and mosfets, And use a plug in system similar to a USB connector,etc? I dont know a lot about electronics but increasing power would be like connecting batteries wouldn't it?


Using a 555 timer is possible (I did it) but the PIC drops the needed components down a lot. If you used a 555 timer, you would only get the PWM output, not any current limiting. Then you have have to create a comparator setup that would read the current sensor and stop the PWM output when it reached the predetemined level. Using a PIC, all that is done on a simple chip, and it can be programmed with different current limit levels.

Putting the controllers is parallel is kind of like connecting the batteries, but there would need to be large buss bars to connect the large power sections on the controllers together.


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## Beyonder (Sep 18, 2008)

interesting...I look forward to seeing your pics of your controller


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## piotrsko (Dec 9, 2007)

ever think of using the sound inputs on your PC as an el cheapo scope?

buffer the inputs to not exceed 5V (although I think they can go to 10V), and use the sound editor to look at the waveforms recorded.


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## TheSGC (Nov 15, 2007)

piotrsko said:


> ever think of using the sound inputs on your PC as an el cheapo scope?
> 
> buffer the inputs to not exceed 5V (although I think they can go to 10V), and use the sound editor to look at the waveforms recorded.


That thought did cross my mind, like only use 5 volts for the gate driver and that should be somewhat safe. However, this week I am going back to the Electronics Supply room and asking if I can borrow one of the dust-caked oscilloscopes in there.


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