Reliable and Flexible Switching System

[Farmhand]

Seems to work ok, I did put 10 Ohm resistors between the driver outputs and the gates, at lower frequencies like under 400 Hz the hi gate drive drops a fraction I think. It seems to switch transformers quite well, I tested a ferrite core transformer up to 200 kHz and also a steel core at 400 Hz. The 10 Ohm resistors seemed to take out a lot of the noise I could find at 200 kHz

I've noticed before that the gate driver chips I used for low side switches (TC4420, 6 amp parts) can get quite warm to hot when I try to use them at over about 900 kHz, and previously I have used two low side mosfets out of phase to switch the same coil so as to share the load and better handle the higher frequency I wanted.

So I'm thinking that it could maybe be beneficial to make a four phase signal to switch two half H bridges one after the other to share the load of switching the same coil, all the previous components in the signal train seem to be able to handle higher frequencies no problem. Effectively either double the reliable switching frequency or halve the work on the switches and driver chips.

Keeping dead time minimal while avoiding shoot through current seems to be the challenge, I'm sure that can be better adjusted with a different signal arrangement though. If I power the signal components from 15 volts rather than 5 volts they should work quicker. Only the micro is limited to 5 volts. Unless I'm reading the data sheet wrong it looks like a CD4049 chip which I have, if it is powered by 15v can translate a 5 v signal into a 15v signal, I think the data sheet is telling me it will do the opposite so I'll have to try it and see. 

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[EMJunkie]

Hi All,

What Microcontroller do you think is best for this project? Price wise and Feature wise?

BeagleBone (Black Series)   -     3 (75%)
FEZ Hydra                          -     0 (0%)
Arduino Mega                     -     1 (25%)

All the Best

  Chris

[EMJunkie]

@All - I have been in conversation with my friend Albert. We have been talking about pricing on the setup he has.

Can anyone make any recommendations on a cheap Chinese Manufacturer that can also place the components?

All the Best

  Chris

[Farmhand]

Hi EM, is that a setup you posted previously in the thread ? I was thinking about the poll and maybe the low votes was because in essence all the micro's do basically the same stuff so it's difficult to say. I'll buy and use whatever I can get code for or write code for. 

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[EMJunkie]

Hi EM, is that a setup you posted previously in the thread ? I was thinking about the poll and maybe the low votes was because in essence all the micro's do basically the same stuff so it's difficult to say. I'll buy and use whatever I can get code for or write code for. 

Hi Farmhand,

Yes but the V5 Version. I may have posted V1 or something.

Not sure I understand you fully, if I do understand, then I would have to disagree.

Microcontrollers are awesome. Micro's are the heart of any system, or better, the brain. At all costs we need to protect our Microcontrollers. The whole point of this thread is to achieve a result and that result is to use a Microcontroller that can control a Highly Flexible Highly Reliable Switching Unit.

A unit that can do most anything we want it to do, this can be controlled by the Microcontroller...

So a Micro controls a top of the line Switching system, this switching system can switch all sorts of Frequencies, it can do all sorts of Duty Cycles, It can be an Isolated H-Bridge, Isolated Half H-Bridge, Single Isolated Switch and so on. Multiple Frequencies on each Isolated Single Switch...

So This Switching System is only a part of the equation, not the full System and that's why I wanted to know what people thought of the Microcontrollers, remembering some are much better for this sort of thing than others. For example Raspberry Pi is not one I would use, Arduino Duemilanove/Arduino Uno is last on my list, many Micros are not really satisfactory for a project like this. Of course this is my opinion.

There is no way a Microcontroller can switch any sort of Load, maybe at most 1/2 a watt, with most Microcontrollers. The Tantratron is rated to 1600VA.

The Micro might shut down the entire system in the event of an overheat for example...

All the Best

  Chris