L297 with MOSFET H-Bridge

[joprinz]

Hello Everyone,

I have been using the L297/L298 based drivers for driving stepper motors for my hobby CNC Router. I'm using 2A 155 Oz.In Portescap steppers at the moment. But my feed rate as well as the Jog rate are very low. So I want to upgrade the steppers to higher torque ones. But most of the steppers i found in the 450Oz.In range are rated 5A and more. So I cannot be using the L297/L298 combination anymore. I did some reading about stepper drivers and found a few people using the L297 to drive a MOSFET H-Bridge and thus providing Higher currents to the motor. However I am not able to find a schematic for the same.

I hope someone can provide me guidance for the same. Any Schematic/Circuit idea/suggestions/opinions regarding the same is highly appreciated.

Please Advice!

Thank You,

Joe!

[fernandodiaz]

Hi i think you need regulation curent and  increment voltaje

you can run the strepping motor high speeds so 1000 - 1500  RPM with good  torque
make ramp acceleration and  unaceleration if system is much friction

read this:
http://www.cs.uiowa.edu/~jones/step/current.htm
when start pulse  increment a short time high voltaje, this increment torque & speed
see figure 4.5  link below
is best use bipolar circuit and motors in low speeds draw more torque

best regards

[joprinz]

Thanks Fernando Diaz.

But the link U sent seems to be not working.

Joe!

[savnik20]

Thanks Fernando Diaz.

But the link U sent seems to be not working.

Joe!

Look again : http://www.cs.uiowa.edu/~jones/step/current.html

[magico]

Hello, search in www.cnczone.com /forum/open boards...


Magico

[avralam]

Accurately
look @ avr32 posts in:
http://www.cnczone.com/forums/archive/index.php/t-9145.html

[myheadhurts]

there's a wealth of data here...

http://www.pminmo.com/
PMinMO DIY Electronics, A3977, L297, L298, drivers, PCB's, CNC, toner transfer, ss3977

[Naste]

Hii

#first way..you can use that motor stepper :

260 OzIn 4-Wire Stepper Motor

    * 260 Oz In. Hybrid
    * 1.8° /200 Steps Per Rev.
    * Rated 12-24 Volts*
    * 2.5 Amps Current Per Phase
    * 4-wire Bi-polar
    * NEMA 23 Frame
    * Factory Enameled Red Body
    * Now with dual shafts!
 it about $40 or you ca visit http://www.probotix.com/stepper_motors/ht23-260-4/

#second

if you still use your 450 oz.in with 5 amp, you can pararel your L298 output so it can supply up to 8 A,(pin 13 with 3, and pin 2 with 14)

have fun bro..

[Ichan]

you can pararel your L298 output so it can supply up to 8 A

Are you sure? My understanding is L298 in parallel can output only 3A continously.

http://www.cnczone.com/forums/showpost.php?p=443764&postcount=8

-ichan

[Naste]

are you sure too? coz  i have read the datasheet that l298 can supply up to 4 Amp. so if we pararelled it can  supply up to 8 Amp.

[Ichan]

You need to understand what "peak current" and "continuous current" mean.

-ichan

ps: just find the datasheet, see "Absolute Maximum Ratings" and first sentence on page 8 of ST L298 datasheet about paralleling the outputs.

Edit: It just too naive to add 4 + 4 = 8 for this case, many other aspects need to be calculated, for example see figure 7 - the total current of parallel configuration will be limited by chip bonding strength of VSS pin. Here on parallel configuration 2 + 2 != 4, it is 3.5 for repetitive (pulses) or 3 for DC (continuous), not stated on the datasheet but i guess 2 + 2 can be 4 only for non-repetitive (single pulse, t=100uS AMR said).

[Naste]

Ichan,
I think i have a mistake, i have read again about L298 and you are true about the problem. 4 Amp is the maximum after pararelled..thanks guys

[Codeman]

Hi,

I had found this schematic after some digging on my PC 

The schematic is not mine and I dind't test it. Maybe it can help someone. Uses L297/L298 and IRF510 FETS.

http://www.mydrive.ch/en/download.php?id=5562542

Best..

[joprinz]

Thank you all for your inputs.

Codeman, The link you sent seems to be not available anymore. The link is getting redirected to the Site Index Page "http://www.mydrive.ch/en/"
Can U plz reupload it?

Thank You,

Joe!