DC Brushed Motor Control

[tonyweldon]

Hello all,

I want to design a new brushed dc motor control (H-bridge) using a PIC controller. I notice that some devices e.g. 18F2331 have a Power Control module which seems to offer help with certain motor control parameters such as dead-band.On the other hand, Microchip's application sheet AN893 suggests that I should be using a PIC with the ECCP module e.g. PIC16F684.

Can anyone offer advice as to which way to go please?

For this project, the cost of the micro is not important. I am more concerned with ease of software development.

Many thanks in advance.

[z3ngew]

hi there,
according to your motor specification, you will decide the h-bridge driver parameters, (volt, current, switching speed, etc)

the micro controller role is to switch the circuit only, but the driver is different circuit which should be isolated from the mcu in order to protect it.

also there is an h-bridge ic (LM293)
see the data sheet and if it suit your motor specifications, it will save you a lot of trouble.

Good Luck,
z3ngew

[tonyweldon]

Thank you.

I understand the need for a purpose designed output stage/bridge. What I need to know is whether to use the ECCP offered by some PICs, OR the Power Control Module offered by other PICs, to control the bridge circuit?

Regards

[temtronic]

Unfortunately, without knowing what motor, no one can really say which PIC to use.
There's really 4 parts to this problem
1) motor
2) driver
3) controller(PIC)
4) code

2,3,4 all depend on knowing what 1 is....

depending on the 'project', even a PIC16C84 could do the job(BTDT).If cost isn't a huge concern, there are off-the-shelf 'controller-driver' units that accept commands and motor does as told.

kinda specifying a car for you...need to know what it's for...pleasure,off road,hauling people or trash,economy,gas/diesel,colour?

hth
jay

[tonyweldon]

The motor is actually a large linear actuator drawing up to 30 amps at 24 volts, slow moving with a linear potentiometer position feedback. I have the power stage and feedback electronics covered. I just want to know whether to go down the ECCP route or the Power Control Module route. I expect either will do the job, but I am hoping that one or other has a reputation for ease of use and flexibility?

Thanks

[SherpaDoug]

Do you need 4 quadrant control? (bidirectional driving and braking)
_________________
The search for better is endless. Instead simply find very good and get the job done.

[tonyweldon]

Yes I do.

Thanks for your reply.

[Ttelmah]

The ECCP predates the power control module. The application note dates from before the later module existed.
Both have deadband control. The ECCP does all that is 'needed', and is easier to setup.

Best Wishes