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Transistor Curve Simulator

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MRacerxdl

Sat May 07 2011, 03:59PM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

Hi, I made a Transistor Curve Simulator for helping people choose between IGBT and MOSFET.

Here is a pic:
5696561346 B43b610398

It has two options:

Manual or Automatic Data: You choose to use a few preset MOSFET/IGBT or put the Manual VCE/RDS Data
Manual or Automatic Scale: You choose to use a Automatic Scale Mode or Manual

It basicly gets the Vce or Rds and makes use of the ohm law to plot the graph. If its an IGBT and a Mosfet comparing, it plots a point when two pieces dissipate same heat, as a Common Power Dissipation. So you can see from where current/power the IGBT or Mosfet is better.

It still have bugs, and I will made more options to DRSSTC users, like calculating Temperature of IGBT (I know, in the pratice it can be very different to calculations, but some prediction is good), delays, and average power from Duty Cycle.

Also I need to add more IGBT/MOSFET at my database list, someone can suggest more IGBT/MOSFET?

Here is the link:

(Its in portuguese)

You can click the link of "Translate this page to english" or access here:

If any button doesnt work, refresh the page, that is a know bug, but after refresh everything works fine.

Tested at Firefox, Google Chrome and Internet Explorer 9 (older versions is not sure to work, that is why my page warns about it.)

Thanks!

Patrick

Sat May 07 2011, 05:38PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

this is a great tool.... if it works. I will put it to the test.

MRacerxdl

Sat May 07 2011, 08:39PM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

It isnt working? What browser are you using??

Patrick

Sat May 07 2011, 08:43PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

MRacerxdl wrote ...

It isnt working? What browser are you using??

It works fine, just deciding if its useful.

I presume the vertical axis is wattage dissipated through the transistor? some of the graph seems to read a bit high though?

Here are some of my personal favorites...

MOSFET, Rds=0.56 Ohms
IGBT, Vce(SAT)--1.8 to 2.6 V @ 25C, 1.6 to 2.0 V @ 125C, 1.7V is typical for my apps.
IGBT, Vce(SAT)--1.9 to 2.7 V @ 25C, 1.6 to 2.2 V @ 125C. 1.8V is typical for my apps.

My conclusion: This may be useful to some people for deciding on the max/min optimization question. Below certain V and I, MOSFETs are better, above that mark the IGBT's become better. The graph is useful, but the overall program output is only as good as the data input. Since there is some varience in the Vce(SAT) number, the user must know what the effective Vce will be for their chosen circuit. Unless the uncetainty between Vce(SAT) typical, and Vce(SAT) max, is outside the region where there variability will matter,else no useful comparison can be made.

MRacerxdl

Sat May 07 2011, 11:39PM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

Added all three transistors :D
Yeah the Vertical Axys is the dissipate heat... But I didnt limited it to anything, because it can be pulsed, so its the heat dissipated in the moment.

My Database has the Vmax, Imax25, Imax100, Ipulse, Vce/Rds, Power Dissipation, Td(on), Trise, Td(off), Tfall, Qge/Qgs, data, for future use.

And as you said, there is a difference between the typical and max. I always use tipical in my database, but I know that this can vary.

That will be for reference, in near future I will put also a delay calculator, and gate current draw calculator. Things that will be also for reference, since much things can vary in the pratice.

I think its like building a tesla coil, you can calculate everything with the most precision calcs, but in the pratice you have much more things to worried about, things that you cant even predict (like atmosferical things or so) that changes the calculation. But the calculation helps ALOT to get you to your tesla coil, but it doesnt eliminate the manual tunning from that.

Edit: About the scale, you can make your own scale, by disabling the autoscale mode :D

Patrick

Sun May 08 2011, 04:35AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

If you could do some math on resistors watt/ heat dissipation in air, then heat dissipation in oil given the same temperature rise. That would be useful to me for my HV resistors.

One thing I found is that the specific heat of oil is way higher then air, same goes for thermal conductivity.

tarakan2

Tue May 10 2011, 12:42AM

Registered Member #3859 Joined: Sun May 01 2011, 03:47PM
Location:
Posts: 179

MRacerxdl, ever since I started using this forum you have been a mystery to me. I don't understand how you make so many projects, have a very legitimate website with so many tools and are completely fluent in English.

Only now I accomplish a lot of things mainly because USA has a lot of interesting things dumped in trash.

tarakan2

Tue May 10 2011, 01:07AM

Registered Member #3859 Joined: Sun May 01 2011, 03:47PM
Location:
Posts: 179

Patrick wrote ...

If you could do some math on resistors watt/ heat dissipation in air, then heat dissipation in oil given the same temperature rise. That would be useful to me for my HV resistors.

One thing I found is that the specific heat of oil is way higher then air, same goes for thermal conductivity.

Oil prevents sparkover. That is how a voltage multiplier can be kept compact.
Just make sure it doesn't heat up and explode.
Also the paraffin wax has an ability to heatsink things.

MRacerxdl

Sun May 15 2011, 05:52PM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

Patrick: You mean, You put a resistor Wattage and Resistance, and calculate the temperature on air, and for a given oil for comparison?

I can do this, I will search the formulas. In eletronics technician I already learned that, but that was few years ago, and I didnt used it, so I almost forgot :P

Thanks Tarakan2,
I want to help people that doesnt know how to do things. And also, I make things for the people of my country (Brazil)
There is some prejudgement of brazillian people from outside of brazil, but here we have the best colleges and best eletrical engineers for a example. But all of the best, goes to work outside brazil, and not all times you hear about them.

So my website if for helping any people to construct things and getting knowledge about it. Much people has potential to do that, but lack of content in portuguese or people to help, is a big problem here (Its nothing compared about the taxes from imported things, but its a big problem too)

Patrick

Sun May 15 2011, 06:44PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

I mean this:

Given the following, 13.8kV, 4.6 watts @ 70 degrees C in air.

Then what would be the wattage in a infinitly large oil mass for the same internal temp of the resistor?

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