Disabling auto-off on a Sunbeam Health at Home heating pad
Posted by hank, Thu Dec 13 01:29:00 UTC 2007
USE CAUTION! TRY AT YOUR OWN RISK!
YOU WILL VOID YOUR WARRANTY!
So, I got this heating pad at the store a while back to use as a hedgehog heating pad. I found out that the 2-hour auto-off timer was hardcoded into the circuit, and they didn’t even bother to put a switch on the casing to disable it. Typical overprotection of the consumer - this wouldn’t exist if our country was a bit less litigious…
African hedgehogs need at least 72F to be happy, so a heating pad under the cage is recommended. I mean, how could you not help this face?:
So, to disable it, I decided to take it apart and find the culprit like this guy did. It’s too bad that for some reason they decided to make it even harder to change this “feature.” Here’s the outer casing:
Here is an overview of the circuit board:
It’s an Eagle LOPP4, and apparently it was made on Christmas of 2006 (2006-12-15)! It also bears a marking of 07.28, and I have no idea what that means.
So, the deal is that after a lot of trial and error, I finally found which single pin on the IC you have to cut. I’ve circled the IC here:
It’s PIN #2!
OK, it actually isn’t #2 on the schematic, but in the picture it makes sense. Just take a soldering iron and a sharp pointy object (I used a thumbtack), melt the solder, and pry the pin from the board. Be careful not to touch pin #1 - if you disconnect it, it will turn off every 5 minutes! Then, put the entire thing back together and celebrate!
I used the datasheet for the IC chip to figure out what pins to screw with. I can’t find the number of the chip right now without tearing the whole thing apart again. Basically, the chip is just a counter, and you cut one of the pins that makes it increment. So simple.
Now I have a happy hedgehog. He’ll never be cold again.
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December 13, 2007 @ 05:52 AM
won’t be cold again, but when you come home to find Hedgehog Toast, what will you say then Mr. “I Hacked My Heating Pad to torch my pet”?
I bet trpik will not make you cheese toast then. no sir.
no cheese toast for you.
none
December 18, 2007 @ 01:50 PM
Nice hack. I’d have just cut and hardwired, your’s is more elegant.
Just an FYI. These timers are there because if you fall asleep on a heating pad it can cause neurological damage, like Bell’s Palsy. I don’t think Sunbeam ever came up with a use case that included hedgehogs, so I forgive them.
December 20, 2007 @ 04:59 AM
Why? Just why? What do you think are the possible reasons for this “safety feature”? Is it there for something to bypass when bored? Is it there so SunBeam can charge twice as much for Hedgehog Heaters as they do for heating pads? Is it there so if I fall asleep with it under my leg I won’t bleed brain fluid from my eyes? Is it there so you don’t burn your house down?
Dumb Ass! Get a heat lamp.
December 20, 2007 @ 05:23 AM
Are U Dum?: You obviously know nothing about hedgehogs. Heat lamps are a very bad idea, use WAY more electricity than the heating pad, and are way more of a fire hazard. Also, burning my house down isn’t an issue, and I put that at the top to warn people who didn’t look at the datasheet not to screw it up. I happen to know how integrated circuits work, especially when they are as simplistic as a timer - maybe you don’t.
The heating pad has been running for a week, like I thought it would, and the hedgehog is very happy (and warm of course). There are no heating pads currently sold that do not have this “safety feature,” so I had no choice. I’m just letting others know since they should be able to disable it if they would like to in return for voiding their warranty and chances for legal action against Sunbeam,
I’m sorry that you don’t like reverse-engineering. I hope you live a nice life full of safety and trust in corporations, since they’re just looking out for our health interests and not protecting themselves from being sued. Oh, and I hope you don’t have a laptop, because I hear those burn down like mad…
December 20, 2007 @ 05:48 AM
Awesome Chacos dude.
December 20, 2007 @ 05:51 AM
cute hedgehog, happy heating, forget those guys…
December 20, 2007 @ 08:10 AM
I too have a hedgehog, and she’s got a heating pad…we just so happened to have a pad back from before they had the auto-off feature! Though, if it ever poops out on me, this will come in handy! Thanks!
December 21, 2007 @ 02:40 AM
We bought a heating pad for our cat from the local pet store. She’s 17 and likes to be warm. The pad is designed to stay on all the time and we have a happy kitty.
December 21, 2007 @ 10:38 PM
If the heat pad is underneath the hedgehog, won’t he just go on it and get it dirty? Why wouldn’t you just use a space heater or heat lamp?
December 21, 2007 @ 10:41 PM
Ben: It’s under his cage on low, heating by conduction. Good question, though. This way, it heats the plastic surface under him, in turn heating his bedding, and we never have to clean it.
Space heaters and heat lamps use much more electricity. I don’t want to pay $30/month to heat my pet.
October 03, 2008 @ 08:06 PM
I have a Sunbeam model 734-5 and the circuit board doesn’t look like that. Any ideas? Anyone get this to work for that version?
How’d you look up what to cut/ etc?
October 04, 2008 @ 06:18 PM
John, I looked up the datasheet for my chip. If you can find the model number of the IC chip, I could probably figure out which one to cut, or at least attempt to, provided you would free me from any liability for any consequences… :)
Here is an example datasheet. They’re usually PDFs. On the right is basically the only diagram you need. If I remember right, I simply disconnected the OUTPUT pin from my chip, so when the timer went off, it didn’t trigger the relay that would shut the heating off. Good luck!
November 16, 2008 @ 04:06 PM
Hi. Thanks for posting this info on disabling the auto shut off on your heating pad. I need to bypass my Sunbeam 536 auto shut off for different reasons, but still necessary. I am getting supplies to make Kombucha Tea. This is a fermented health drink that needs to remain at a temperature of about 84 degrees for 2 weeks. Sitting the bottles of cultured tea on a heating pad is the desired method.
Can you guide me with this model if I send you a digital picture of it? I would really appreciate. I’ve been searching all morning for postings on this matter.
Scott G.