Tronic's DIY dual Mosfet H-bridge (DSMhb)

Re: Tronic's DIY dual Mosfet H-bridge

Hi Thanos,

I'm very curious to see the results of the tests with the wipermotors.

I'm still planning to build your H-bridge.

I haven't found a cheaper suplier yet, the cheapest one still costs over 50 euro's for the materials. May i ask you to reconsider your proposal of sending me the materials.

Thanx

Regards RoVoR

Re: Tronic's DIY dual Mosfet H-bridge

It will be done, exceptionally for you only, inside this month... Will PM you for details...

Regards, Thanos

Re: Tronic's DIY dual Mosfet H-bridge

Hi,

I did some very interesting comparison tests between the DSMhb (dual simple mosfet h-bridge) and the RNVN2...

I connected the same wiper motor and 12volt (battery source) to see the difference between them... I found that the 24Khz PWM frequency was affecting the RNVN2 and not the motors!!!

While RNVN2 produces noise and bad motion during acceleration, the DSMhb was going wonderful! No noise at all and it was keeping the torque on the motor even with slower speeds fine!

I took a comparison video to see how each one behave:

http://www.youtube.com/watch?v=xe2v6zZ7P28


So, I think I made an even better motor controller than a commercial one!! Cool! And it was not even get warm with wiper motors! I think it will work nicely even with larger voltage motors (24volt or 48volt!!!)

I will lower the PWM frequency of my AVR motion controller down to 18Khz and try again with the RNVN2 later. I altready have two RNVN2 motors controllers, and probably, many of you have also a RNVN2 or other motor controllers with simular PWM freq limitations and I don't want these to go wasted... At least now I know the source of the problem...!


Another thing I wanted to mention is that looking closer the windings of a wiper motor I saw that its designed to allow more current to one direction than the other. I figured this out also by watching how the contacts of each winding are placed. So as I see it, maybe there is no cure to make the motors turn both directions with same speed unless you rewind it properly.





Regards, Thanos

Re: Tronic's DIY dual Mosfet H-bridge

Hi there,

First... very good job Thanos. You have come a long way.

If we use wipermotors, we have to mount them in opposite ways to keep the speed the same, right?

Regards,

Jeroen

Re: Tronic's DIY dual Mosfet H-bridge

Hi Jeroen,

Yes, theoretically it should work, but I fear that will be friction of the cable (or belt) on the pulleys of the two motors. Their gearbox is trapezoid that means that the faster motor cannot push faster the slower motor... Only experimenting will show if its ok after all.

Yesterday I had a meeting with my 6DOF programmer (John, or else known, Planmix) and said me that he found some 24volt yacht wiper motors that have lifting capacity of 100Kg /cm2 !!!! They are fairly cheap, only 59euro, and I might try them to see If I can interface them to some ball screw linear actuator or something...!!

Regards, Thanos

Re: Tronic's DIY dual Mosfet H-bridge

I have prepared a parts list from http://www.mouser.com for the people in the states. I couldn't find the terminal blocks online. I'm sure they are their. Any changes or additions please let me know.

AVRandHbridge_partslist.xls

Thanks
Matt

Re: Tronic's DIY dual Mosfet H-bridge

Hi Thanos,

THANX MAN I realy appreciate that. Can't wait to receive your PM.

I was thinking about the windings on the wiper motors, maybe I'm wrong, after all I do not have very much knowledge of electronics. But..... can't the difference in speed be resolved by a variabel setting in the software (direction A = direction A (normal windings) , direction B = direction B * x (lesser windings)), if so...maybe x could be changed on the lcd so we can change it to our own needs.

Regards RoVoR

Re: Tronic's DIY dual Mosfet H-bridge

Here is a parts list from http://www.mouser.com http://www.newark.com

let me know what I need to add
matt

Re: Tronic's DIY dual Mosfet H-bridge

I have updated the H-Bridge and the AVR

let me know what you think

Re: Tronic's DIY dual Mosfet H-bridge_

Hi,

Just updated the first post with new goodies including a fixed part list.

Thanos

Re: Tronic's DIY dual Mosfet H-bridge_

Hi,

Here are the updated single PDF PCB layouts for the DSMhb both versions (with or without TC connectors):

NO TC version v1.2:
Dual_simple_mosfet_hbridge_1_2.pdf
dual_simple_mosfet_hbridge_1_2_bottom_single.pdf

TC Ternimal connectors version v1.2b:
Dual_simple_mosfet_hbridge_1_2b.pdf
dual_simple_mosfet_hbridge_1_2b_bottom_single.pdf


Also included Top and Silk layer for reference reasons only. Use only the PDF that is marked as bottom to send to the etching service.

Thanks,

Regards, Thanos

Re: Tronic's DIY dual Mosfet H-bridge_

Hi,

Here is the new DSMhb 1.2b layout made with Sprint-layout5. It includes Gerber and Excellon files!

DSMhb1_2b_sprint.pdf

And bottom side only:

DSMhb1_2b_sprint_bottom.pdf


Here are the gerber and excellon data:
DSMhb1_2b_gerber_excellon.zip


And here are some photos of the PCB using the photo function of sprint-layout5:






Its recommended to use 70um copper-thickness of the lines to be able to achieve 10Amp rate without reinforcing the lines. And if you reinforce the lines with more solder placed on them, you may get up to 25 or 30Amp rate!!!

Enjoy,

Regards, Thanos

Re: Tronic's DIY dual Mosfet H-bridge_

Updated the above post with corrected PDF files

(to be able to print inside the printer's margins with 1:1 ration on A4 page)

And added solder mask to upper copper layer in the Gerber data (total 4 layers now) :yippiee:

And in case you didn't seen it, I have added an extra page on the main PDF that indicates the hole positions along with the drill sizes!!

Regards, Thanos

Re: Tronic's DIY dual Mosfet H-bridge_

:clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap:

Hi! Ich bin der Welt und möchte gleich ein mount zu ihr! Können Sie mir helfen? Ich sah, dass Sie fotografiert haben alles, was ich kann mandaresisch versuchen zu tun für mich?
Danke!

Amonte8@gmail.com
calegari1234@gmail.com

Re: Tronic's DIY dual Mosfet H-bridge_

Ego? Help? Anyone to translate this? The babelfish could not, by the way... :lol:

Thanos

Re: Tronic's DIY dual Mosfet H-bridge_

The text is tranlated to german as well. Honestly, I doubt this text does make any forum related sense in the origin language anyway. Most likely its computer generated spam I think...

Regards
Christian

Re: Tronic's DIY dual Mosfet H-bridge_

hi guys! i am having trouble with this bridge..

i double checked everything and i sodlered everything correctly.

my problem is that on the IRF4905 the trigger signal is only 0.72V instead of 4.8V. the IRF4905 doesnt trigger properly and gets warm. i tried it with the small motor and it does not get warm with that one. so it MIGHT be possible that everybody has this problem but nobody noticed it because of the smaller motors. (im using a 500W motor thats running at 125 instead of 500). the IRF44 work fine. they dont get hot and are ok. im using 3 parallel of each kind to handle the motor.

could somebody please measure the trigger voltage on the most extreme potty positions?

thank you

igor

Re: Tronic's DIY dual Mosfet H-bridge_

Hi Igor,

Perhaps you have burned the 74HC08 chip or the BC546 that is driving the mosfet gates...

But to be sure, I'll measure the signal voltage to the gate of the IRF4905's and inform you about what voltage it should output.

Another possibility is that you may need to change the values of the two resistors that drive the BC546, in order to amplify a little more the signal to be able to turn on all the parallel mosfets you have added!! Perhaps decrease the 1K5 resistors to 1K and the 3K6 resistors to 2K5!

Any photos of the parallel placed mosfets?

Regards, Thanos

Re: Tronic's DIY dual Mosfet H-bridge_

hi!

update, i discovered that i measured the wrong way.. (sorry.. :? )

ok here are the updated correct values measured between pin S and G of the 4905:

with motor battery connected 7,8 V (with potty in max position)
without motor battery connected 0 V (with potty in max position)


on the 44 i measure in both cases 4,8.

i searched for a datasheet of the 4905, and found 2 versions. one with a trigger voltage of 2-4V and one 10-20. what version did you send to me?

pictures of the modded board will arrive soon.

igor

Re: Tronic's DIY dual Mosfet H-bridge_

oki here are teh pictures.. since the quality is bad i made also a jpg that explains how it is connected.