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nickskethisniks
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Joined: 17/10/2017
Location: Belgium
Posts: 458

Posted: 08:46am 23 Oct 2024

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Hi, in an effort to be smart and use the auxillary power of a dcdc converter to power a small panelmeter I destroyed the auxillary IC, I searched the internet and even consulted chatgpt ( wich was spitting garbage btw). The problem is the partnumbers are scraped off.

https://nl.aliexpress.com/item/1005005639051641.html?spm=a2g0o.order_list.order_list_main.305.79cb79d2Wxc69s&gatewayAdapt=glo2nld

The DCDC converter I’m working on is from AliExpress and was functioning well, charging a 24V battery from a 48V input at 10A. However, when I accidentally touched the module, I must have shifted something, which caused a short circuit. The converter powers both a fan and the main PWM controller, which I suspect to be either a TL494 or SG2525, though I haven't confirmed that yet.

I allready desoldered the ic and diode to have a clear view on the tracks.

This converter supports up to 75V input, and I’m trying to identify a SOIC-8 IC part with a thermal heat pad underneath.

The pinout of the IC is as follows:

1: VCC
2: Inductor (suggesting it has an internal MOSFET)
3: Voltage feedback
4: Not connected
5-8. All ground

I could probe the frequency of another module to see what it is.

A friend suggested the AP1509, which has the same pinout but is only rated for 20V. I did come across an IC in the same series rated for up to 60V, but that's still not sufficient.
Ideally, I would like to use an Eltek 48V power supply, which operates at 57V.

If I can't find a suitable replacement IC, I’ll consider powering the converter with an external PSU.

Anyone with some suggestions regarding the ic?

For the record, don't know why but I wanted to build a 4 channel bench psu... it looked handy. So I bought this modules and some other parts on ali to build in a second hand enclosure.

Edited 2024-10-23 18:52 by nickskethisniks

disco4now

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Joined: 18/12/2014
Location: Australia
Posts: 896

Posted: 10:14am 23 Oct 2024

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See this thread.
Reverse engineering a TL494 based Chinese
Could it be an XL7005A ,looks to fit.
From that post.
1800W SCH.pdf
Regards
Gerry
Edited 2024-10-23 20:26 by disco4now

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phil99

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Joined: 11/02/2018
Location: Australia
Posts: 2129

Posted: 11:41am 23 Oct 2024

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The circuit Gerry posted shows it just provides 13.5V to the other chips and fan so you could probably get the 13.5V from one of the other modules, provided they share a common signal ground.

Ziki_the
Newbie

Joined: 13/04/2023
Location: Yugoslavia
Posts: 39

Posted: 04:45pm 23 Oct 2024

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Try this Nick:
pin to pin
They have ac/dc too.

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nickskethisniks
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Joined: 17/10/2017
Location: Belgium
Posts: 458

Posted: 06:10pm 23 Oct 2024

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Thanks, that's great! 99% it's that chip.

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