H-bridge to 100W 24V motor

[olof102]

Hey,
me and a friend are currently building a computer controlled robot. It's pretty heavy, there's 2 12V 7,2Ah batteries and a 100W 24V motor.

It's a schoolproject, and it has to be able to go forward and backwards. Controlled using the LPT (printer port) on a laptop.

We could use some tips on some easy to build H-brigdes that can handle the current, and will work together with the LPT. Circuits?

Thanks in advance!

 

[lion-motor]

vnh2sp30

hi

you can use vnh2sp30 he can drive motors 14A ath 16V max . You can found ath ebay .

 

[cr0sh]

The vnh2sp30 is an SMT IC - so unless they have some skill in SMT prototyping, they aren't going to be able to use it. With that said, though, it is a good IC to use; check out Pololu - they sell boards really cheap which use this chip (or similar) for an h-bridge solution:

https://www.pololu.com/catalog/product/706

Alternatively, you may find that an h-bridge made from relays might work just as well, albeit without any form of speed control - unless you set up a 12/24 VDC relay switching system that can switch the batteries from serial to parallel operation (the motor should still run off of it, just at approximately half the speed and lower torque).

 

[kjennejohn]

This same project was largely posted a few weeks ago, but the poster wanted to use 12V. Here's the page link to a schematic in the discussion:
https://www.electro-tech-online.com/threads/computer-interfaced-based-mechatronics.109048/
W3 and W4 could be connected to 24V supply instead. You'll have to check and see if the transistors can handle the voltage or the wattage as is, and if the 5V regulator for the HC logic part will handle the 24V as well.
W0 and W1, the direction control lines, go to D0 and D1 of the parallel port. This is pretty much all you need for a minimum circuit.

If you want ooh-la la, here's a PIC controlled motor-controller board for $25:
**broken link removed**
The only catch is, you have to buy their inexpensive programmer as well for $15. Pfft, $40 total, no big deal.
Aahh! But you can use their free BASIC to program the PIC to use a couple inputs with the parallel port's D0 and D1 to tell it what to do with the motors! And the control IC choices are:
1. The ULN2803, 8 outputs supplying 500mA each (not constantly!), or
2. an L293 half bridge chip, good for 1 Amp, or
3. four MOSFETS, capable of handling 24V, up to 9.2 Amps EACH!!, for a grand total of 36+ Amps!
BTW, the "inputs" I mention are actually the servo motor control pins, but these can be used as PIC inputs/outputs, there's even a reset pin.
This baby does it all! After your present project is finished, you can reuse this board for all kinds of motor projects: robots, wheel chairs, electic bikes/carts, you name it!
Have a good project!
kenjj