# Big Lots Grim Reaper Hack



## Doc Doom (Aug 28, 2008)

Picked up a Grim Reaper head today. It's just the head, about 2' tall with the black shroud. Runs on 3 AA battaries with a motion/sound activated switch, eyes flash red, makes an irritating oooo-eeeee-oooo-eeee noise. I'd like to mount it on my front door, kill the noise and hardwire it with a transformer for continuous eye flashing. I think I've figured out how to cut out the speaker and bypass the sensor, but can anybody tell me what amp/wattage/voltage transformer to use? I've got quite a collection from my model railroading days.
Thanks


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## Liam (Mar 23, 2007)

Hey Doc,

You should be able to figure out the voltage by the batteries it uses. Since it uses three AA batteries (1.5V each), it technically likes 4.5V DC. I'm not sure if you'll be able to find a transformer that runs at 4.5, but you might get away with a 5V transformer, but it's hard to say if it will tolerate that or not.

I hope that helps - good luck!


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## hpropman (Jul 27, 2008)

If you run it off of 3 D size cells it should get you through the night. If you need longer a regulated 5V power supply should also work. You can make one or buy them on ebay. Drop me an email if you need any schematics or links or anything. if you are only powering the led eyes any transformer with a least 100ma at a least 7.5v but I would work but do not go higher than 12 or the regulator may get hot. This will be fine if you are going to make the circuit.


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## Doc Doom (Aug 28, 2008)

Liam said:


> Hey Doc,
> You should be able to figure out the voltage by the batteries it uses. Since it uses three AA batteries (1.5V each), it technically likes 4.5V DC. I'm not sure if you'll be able to find a transformer that runs at 4.5, but you might get away with a 5V transformer, but it's hard to say if it will tolerate that or not.
> I hope that helps - good luck!


Looks like "or not". I picked up a used 5V transformer for some electronic gadget and hooked it up. Ended up with nothing working and finally little curls of smoke from the LEDs.  Obviously I messed something up. I'm not real savvy when it comes to AC versus DC. What really has me puzzled though is that the LEDs glowed somewhat after I first hooked up the transformer, BEFORE I plugged it in. Must have had a capacitor in there somewhere.

Guess I'll have to get some new LEDs and start from scratch.


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## hpropman (Jul 27, 2008)

I am sorry that you have let out the magic smoke. Unless the transformer (wall wart) said that it was regulated it was prob more than 5 volts and that prob fried the circuit. Transformers are usually 3 or 4 volts higher than they say they are unless they are regulated. when in doubt measure the voltage before you hook it up to the circuit. A multimeter is a must to have. The circuit is prob gone but the motor is probably still good. If you are not going to return the reaper to the store we might be able to help you create a new circuit. On my website is a link to an online electronics course. Also check out this thread.

http://www.hauntforum.com/showthread.php?t=12014


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## Dr Morbius (Sep 21, 2004)

Doc Doom said:


> Looks like "or not". I picked up a used 5V transformer for some electronic gadget and hooked it up.


Was this a DC transformer from a wall wart, or a straight out plain transformer picked out of another circuit? Plain old transformers, although they put out a reduced voltage still put out an AC current if unrectified. That could have fried it real good.


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## Doc Doom (Aug 28, 2008)

Dr Morbius said:


> Was this a DC transformer from a wall wart, or a straight out plain transformer picked out of another circuit? Plain old transformers, although they put out a reduced voltage still put out an AC current if unrectified. That could have fried it real good.


I don't really know what it was from. The connector was a round sleeve style that wouls be inserted over a pin, like in a rechargeable screwdriver. My meter showed both AC and DC. Must have been AC.

hpropman,
Thanks for the links. I'm afraid this dog is too old to learn new electronics. i managed to rig up LED to a 9V battery for my FCG eyes, but that is about the limit for me.

I want to wire the head to my front security screen door so I can't get to the battery to change them when they run out. Is there a cheep, easy way to connect them to a hardwired power source?


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## Sickie Ickie (Jun 20, 2006)

yep. A wall wart cell phone charger. Check the output. You can sometimes pick up a bag of 2-3 of these at the thrift store for under $3 here.


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## Doc Doom (Aug 28, 2008)

S I,
Thanks for the tip. I want DC right?


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## Dr Morbius (Sep 21, 2004)

Yes, DC only.


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## Sickie Ickie (Jun 20, 2006)

Doc's right. Input AC, output DC. I know they have 3 VDC on up.


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## Doc Doom (Aug 28, 2008)

Thanks guys! 
I never notice some of the wall warts say DC and some AC.

I'll also cop to thinking that wall wart was someone's idea of a Walmart joke.


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## Sickie Ickie (Jun 20, 2006)

heh would make sense, but in this case a wall wort is the 120v house outlit.


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## Doc Doom (Aug 28, 2008)

Ok, since I let the magic smoke out of the eyes that came with the reaper, I've wired up a set of blinking LEDs using a 9V battery and some help from this website
http://wolfstone.halloweenhost.com/HalloweenTech/anemak_MakingLEDEyes.html#BasicStaticLEDEyesNoMath
Works great but I'm gonna go through a whole bunch of 9Vs by the time Halloween is over. I'm trying to find a wall wart to use instead. I found a 9VDC, 100MA wart, but it pegged 14VDC on my meter. Will this blow the LEDs? I can't afford to let any more smoke out.
Thanks


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## Dr Morbius (Sep 21, 2004)

The greater the voltage the larger the resistor value needs to be or, yes, you will conjure magic smoke again.


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## Otaku (Dec 3, 2004)

Is the battery just running the LEDs? I get many hours of LED spotlight use from one battery.


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## Doc Doom (Aug 28, 2008)

Otaku said:


> Is the battery just running the LEDs? I get many hours of LED spotlight use from one battery.


Yes, one battery running 3 LEDs (1 hidden blinker LED plus 2 eye LEDs). 
Based on a similar set up in my FCG, a 9V will last 2-3 days.


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