# Power supply replacement?



## Jerm357 (Oct 17, 2009)

I have a Gimme large caged skeleton prop that quit working on me a few years ago. This year I deceided that I was going to get him to do something so I wired up his led eyes and the motor that makes him shake. It works well, but my question is... 

The power supply died on me last year. It was a 9v 2000ma supply. I have been using a 12v 500ma and a 10v 700ma supply and both work well, but Im not sure what could actualy happen if I let him run for about 3 hours like that. I have only tested him for like 20min continuously and the 12v 500ma supply gets warm. Not to warm to toutch or anything, but enough to make me ask this question. I switched to the 10v 700ma because it was a little closer to the original supply but have not done enought testing with it to see what happens with it. I figure I might as well just plug him in on halloween and let it go because if its going to break its going to break. I reather it go on halloween than in my garage testing. 

So what do you think will happen using it like this? Am I looking at burning up the prop or just the power supply or both? Will it be Ok with one of these supplys or should I just wait and get a 9v 2000ma supply. The prop will be used out side hanging from a tree away from people so it should not cause any danger if something went wrong, but I just wanted to hear what others thought about using other supplys in this way because Im not that familiar with volts and amps like this.


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## HomeyDaClown (Oct 3, 2009)

You should stay at or above the original supply rating. Anything less will cause the magic smoke effect to occur eventually (you'll burn up the supply). 

Your original power supply was rated at 18 Watts total output (9 volts * 2 amps).

A 12 volt 500ma supply would only be 6 watts (12 volts * .5 amps), a 10 Volt 700ma supply would be 7 watts (10 volts * .7 amps). Both are less than half of what the original was. The voltage is less critical than the current rating. A 12 volt 1.5 amp = 18 watts and should work fine, but since the original failed at 18 watts, you might want to look for a 12 volt 2 amp instead. 

The longer you run the prop, the hotter the supply will get until it blows.


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## hpropman (Jul 27, 2008)

you may be able to use a computer power supply. They have 12 volts and usually well over 10 amps. Do not worry about too much current the prop will only use the current that it needs.


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## sluggo (Jun 16, 2010)

HomeyDaClown said:


> The voltage is less critical than the current rating. .


This seems like a rather bold assumption. I wouldn't want to assume that the electronic components inside the device, particularly any processors, are capable of handling voltages 33% higher than they are rated for. or that there is a voltage regulator inside the device. Maybe they are, but I wouldn't want to risk it. Personally, I would only replace the power supply with one that has the same voltage and with a current rating greater than or equal to the original.


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## Jerm357 (Oct 17, 2009)

How about a 18v 2.23a adapter instead? I think its the only one I can find thats above the original one.


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## hedg12 (Jul 6, 2008)

I'd stay away from the 18v supply - that would probably be a little much for the eyes, and wouldn't be much good for the motor, either. Give your 10 volt supply a longer test - I'd bet it'll do fine.


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## HomeyDaClown (Oct 3, 2009)

sluggo said:


> This seems like a rather bold assumption. I wouldn't want to assume that the electronic components inside the device, particularly any processors, are capable of handling voltages 33% higher than they are rated for. or that there is a voltage regulator inside the device. Maybe they are, but I wouldn't want to risk it. Personally, I would only replace the power supply with one that has the same voltage and with a current rating greater than or equal to the original.


We are talking about a Gemmy prop running on an unregulated wall wart. The output voltage on a wall wart changes drastically depending on the current draw (load). Especially when the prop has motors, the current draw will vary depending on what the motor is doing at any particular time.



Jerm357 said:


> How about a 18v 2.23a adapter instead? I think its the only one I can find thats above the original one.


That sounds like a laptop power supply and it is most likely regulated so the output voltage will stay around 18 and would not be suited for your prop.


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