LM2596 gets extremely hot

More
3 months 6 days ago #11448 by Joker
Replied by Joker on topic LM2596 gets extremely hot
I'm hoping you can still help me here...

I have connected an osziloscope.
HVD is connected to channel 1 and HV to channel 2.

Figure 23 is the whole process until my power supply switches to constant current at 0.5A.
Then 134V are present at HV (see picture 22) and the noises begin.

If you still have questions about the measurements or need more, please write me. Unfortunately Idon't how the Mosfet must be driven.

Please Log in or Create an account to join the conversation.

More
3 months 3 days ago #11449 by Ty_Eeberfest
I had pretty much dropped out of this thread because it looked as if you and Ian were working it out.

I think we need take a step back. The original problem was that the LM2596 is getting hot. The LM2596 regulates the 5V VCC rail but the HV generator does not run off that rail - it runs off the VIN (presumable 12v) rail. So why are we looking so hard at the HV generator?

Something is loading down the VCC rail. but as far as I can tell the HV generator is incapable of doing that. But that current has to be going somewhere. So the best I can think of is to try running it with all chips removed from their sockets except for the Atmega. Please try it and report back...

Look into it later when the dust is clearing off the crater.

Please Log in or Create an account to join the conversation.

More
3 months 3 days ago - 3 months 3 days ago #11450 by Joker
Replied by Joker on topic LM2596 gets extremely hot
Hello, Ty,
I've now measured C1, this one fits.

At the moment only the Atmel is installed on the board.

The 5V rail runs completely normal without the Atmel. I would also say that the noise comes from the HV rail. Unfortunately I don't know how the HV regulation must look like. Therefore I find it difficult to interpret the oscilloscope images.

I will interrupt the HV-rail again today to make sure that the HV-rail is not the problem.

I still suspect that the Atmel is doing something stupid
Last edit: 3 months 3 days ago by Joker.

Please Log in or Create an account to join the conversation.

More
3 months 3 days ago - 3 months 3 days ago #11451 by Joker
Replied by Joker on topic LM2596 gets extremely hot
Damn, I think I got an idea.

I'm using a new Atmel and I programmed it directly. So it always runs on the internal crystal. That's why the wrong capacitors had no effect. The internal crystal should run with 10Mhz by default (the program was compiled for 16Mhz), I'll have to find out the fuse settings for the arduino - with a little luck that's the problem.
I suggest to mention the fact with the fuses in the manual (when programming with another programmer).
Last edit: 3 months 3 days ago by Joker.

Please Log in or Create an account to join the conversation.

More
3 months 3 days ago #11452 by Joker
Replied by Joker on topic LM2596 gets extremely hot
The faulty fuses were the problem.
Apparently, the Atmel was rocked up by them.

I only have one multimeter at home, but now I can measure at HV 177V. There is no more noise and nothing heats up anymore.

I have flashed the microcontroller according to the following instructions:

www.robotshop.com/community/forum/t/sett...-in-avr-studio/13065

Unfortunately I could not reach the Atmel via the STK500. So I uploaded the hex-file via the Atmelstudio (you can find it under:
c:\Users\name\AppData\Local\Temp\arduino_build_569608\
or search for the file FirmwareV2.ino.hex

:woohoo:

the current consumption is about 0,05A and after a while it drops to 0,01A (surely after the HV string was switched off)

Please Log in or Create an account to join the conversation.

More
3 months 3 days ago #11453 by Ian
Replied by Ian on topic LM2596 gets extremely hot
The internal clock can only run up to 8MHz, and that will not provide the boost frequency needed.

Well done for having that flash of inspiration!

Ian

Please Log in or Create an account to join the conversation.

Moderators: AccutronTy_EeberfestIan
Time to create page: 0.101 seconds

Search

Tube Suppliers

Go to top
JSN Boot template designed by JoomlaShine.com