Russian 2DOF wiper motor simulator

Thank Frakk! I did not expect that you answer so quickly! Your modification is very simple and I like that. We are not afraid to experiment and we'll try it in the next couple of days.

The pleasure is all mine!

Please keep us posted about the experiments. I have a simple H-Bridge built on my breadboard using two IR2110 drivers and four N-Channel MOSFETs. I just have to do the finishing touches on the circuit and make it compatible with the AMC and design a PCB for it.

Regards,
Adam

Of course, we describe the results of the tests. Also we are very interested in your version of Hbridge.

we are just experimenting with hbridge and after the weekend will try to share the results. :brows:

Thx Frakk!
So we were on the rightly think ..
PS. more variable resistors must be purchase

Hi Adam!

We have tested your modification and it works, but not quite. Now we have about 12v - z44, 8v - 4905. loss of voltage currently about 0,3 v on both mosfets's and much less heat. We think that it is necessary reduce the resistance as we have show in the figure. Today we did not have resistors and the time to check it. If possible, we try it tomorrow.

WBR, Nickolay.

Oops! You are right Nickolay! I overlooked that part.

Now with the modification we introduce a parallel resistance, routing the current away from the top. You can take out the 1.5K resistor completely and replace 3.6K to 1.5K. It should work fine like that. For the high-side transistors, you should be measuring between gate - Vcc (source) and not gate - Gnd (drain). Fig.3 in the datasheet shows you should have about 8-12V.

I posted the plans and schematic of my H-Bridge, I would like everyone's opinion about it!

Hi x-simers!

Hi Frakk!
We have some fun ...

http://www.youtube.com/watch?v=fZ4Hqf7a-Ps

resistors must be changed for the ideal...

2Frakk: this cold as ice :cold:

Great! I am happy to hear the modification helped!

H bridge MOSFET gate

If you read this discussion on this forum
http://www.electro-tech-online.com/elec ... -gate.html
They say that the Gate of the Mosfet should always have a resistor connected to it to stop Parasitic oscillations, the discussion has some interesting reading on using Mosfets in H-Bridges.

The gate on the the Mod for the IRFZ44 has no resistor at all, read the posts on that forum and see what you think?


DO and DON'Ts for MOSFETS

Definitely a must read for rookie engineers

http://www.irf.com/technical-info/appnotes/an-936.pdf



Senetor

Are you referring to R5 and R7 in the original post?

R5/R6 and R7/R8 is a voltage divider, and you are right, there is no actual resistor. The transistor acts as a variable resistor, you pump current through it's base, resistance between collector/emitter goes down. No current through base, the transistor has an infinite resistance (in theory). The 1.5K pulls the gate down to 0V without the signal, and also shunts the current down to prevent oscillation. I don't think anything else is needed, although I would love to look at the circuit with an oscilloscope.

Gate driver ICs like the HIP408x or IR2110 will require a small series resistor because currents flowing directly in and out of the gate. With a voltage divider situation, the gate is only tapping into the current flow where the voltages turns it on.

Thank you all for the mod. I also try some changes to the hbridge. Now what is the changes last circuit you use in your video.

We added the transistors on the advice of Adam. But even small changes are needed. We wrote about this earlier in this thread.

Hi all!

I continue build our motion sim. Here is small video about it.

http://www.youtube.com/watch?v=_XyxdbQxKN0

I've added the transistor also and what about the resistor values? Did you remove the 1K5 and decrease 3k6?

We really think that this will work, but we have not verified this. Most likely we'll do it the day after tomorrow.

Hi All!

We failed to alter H bridge on the advice of Adam. We are working with only one connected bipolar transistors. That is, we tested only in one direction. Once we set the second transistor, we obtain a short circuit. We tried various ways, but unfortunately we did not work. But we found a different solution. We replaced the mosfet IRFZ44 at logic level mosfet IRLZ44. They are heated much less. Now we have a normal working HBridge and now we continue our project.


And so we are very pleased to see that Adam is continuing its project to develop HBridge. We are ready to do it immediately after the tests.

WBR, ru.null

Photos and pictures from datasheets of both mosfets.

Perhaps the simplest solution is to use the logic level transistor. I don't know why you got shorts, but now that you fixed the overheating it doesn't matter. I will keep you updated with my h-bridge, it is hard to find time and resources I need for development

Hi All!

Some updates. We install the electronic and electrical components in a single enclosure. Old UPS.

And also we filmed the video with all connected components in action.

http://www.youtube.com/watch?v=ZwB7ODoS0g8

FRAKK! We trust that you will do it! :