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Finding datasheet for a chip

I recently bought a heating pad which has a "feature" which shuts the heat off after 2 hours. Virtually all pads seem to be made this way now, unfortunately. I would like to defeat this. I can probably jumper around the timer control portion of the switch to accomplish this, but I see in doing some searching that on at least one older model, some modification of the circuitry around the chip can accomplish this, too

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Unfortunately, the circuit on that pad is not the same as mine, which is centered around an 8 pin chip marked "SEDS 13-000022 R1017A" I can't seem to find any data on this chip. Tried
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no info that I could find. Anyone know where I might look, or have any other ideas for eliminating the timed off action?

TIA

Dan

Reply to
D
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A 555 timer chip is only eight pins but so are many smaller microcontrollers. Can you take a picture of the circuit board (both sides, perhaps) and upload that to Flickr, ImageShack, or similar? That might help narrow down the choices somewhat.

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Rich Webb     Norfolk, VA
Reply to
Rich Webb

I suspect this is probably a Chinese in-house number. The chip could be anything and there is unlikely to be any data out there on it.

Gareth.

Reply to
Gareth Magennis

True but it's most likely going to be a counter like the other examples or, perhaps, something more modern like the aforementioned uC with an internal RC oscillator. Could be a 4-banger, even. But looking at where it is in the layout can give some clues to getting the OP a way to accomplish his intent.

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Rich Webb     Norfolk, VA
Reply to
Rich Webb

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Thanks for the great replies. I'm not sure what the chip is, it's a SOP8 package, not a DIP like a 555 timer. Probably right, some proprietary design with little data available. One side of the line is switched via a small transistor, I disconnected the transistor & ran that side of the line directly. Heat levels are adjusted with the control switch on the other side of the line. So far so good. Also, the bloody thing is SUPPOSED to shut off at 2 hours, and it's barely making it past ONE. PITA.

Dan

Reply to
D

I just re-read this & want to clarify that the pad IS now staying "on", after the mods. The message above may not have been clear. Thanks again.

Dan

Reply to
D

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