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Evil, Wicked, Mean, Nasty
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Discussion Starter · #1 ·
"Props" (pun intended) to whomever posted the thread on a 3-Way....whatever it was. I can't tell you how many times I saw the heading and figured one of the other make-n-take groups was having more fun than ours. Oh well, on to the topic..

I recently tore apart a headless Gemmy prop to make use of whatever I could salvage. It had a great sound board in it...loud, understandable, with a good pir trigger. So I asked a few of our electronics gurus for assistance on using the sensor and speaker to trigger a R/S audio card or other. (I wanted audio better suited to other props.)

Otaku shared a cheap solution he designed for triggering sound cards, leds, etc. He may have posted something similar using a darlington, but this one should be more reliable. With his permission, I'll post it here.
 

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Evil, Wicked, Mean, Nasty
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Discussion Starter · #2 ·
Otaku has a thread for a timer that works with a talking pumpkin insert from Radio Shack. Right now, those inserts go for less than a U.S. dollar on clearance.

Using this $1 toy from Radio Shack, you can take the screws off the top, remove the sensor, gut it for all the leds and free batteries, and then use that sensor to make this small board that can be used to trigger things that might otherwise use a contact switch.

In simple terms - make one of these to trigger cheap sound cards, leds, even those little cheap-ass screaming boxes.

For my purpose, I'm going to forego expensive solutions like amplified speakers and guitar amps connected to mp3 players for my individual standing props like shiatsu zombies, werewolf, and Frankenstein monster.
 

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Evil, Wicked, Mean, Nasty
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Discussion Starter · #3 ·
If you have ever talked to Otaku about electronics, it's easy to feel like Richard Dreyfess standing on Devil's Tower, watching the colored lights as they play the five tones. To put his language into mine, I created the following sketch....

 

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Evil, Wicked, Mean, Nasty
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Discussion Starter · #4 · (Edited)
PLAY THE FIVE TONES -

The board takes the PIR sensor's voltage and uses it to switch an electronic thingie called a IRF510 MOSFET. The MOSFEt is used as a relay so you can dry trigger a device, or connect a device like one of the USB audio boards that has ~4VDC on it's trigger wires. The MOSFET will switch up to 5A at 100VDC, but if you need to switch that large a load you probably need a heat sink.

The PIR will send out 2-3 voltage pulses each time it "sees" a heat source, in the 2VDC to 3VDC range. There is a short pause between the sets of pulses as the IC resets, usually 3-5 secs. This means that devices that can't handle multiple trigger inputs in rapid succession will have a problem with either re-starts, shutdowns or both. Fortunately, the electronics123 USB board has a software option to ignore triggers while the board is playing. The 20 sec R-S boards also seem to ignore triggers during playback, as do ISD2500 series chips.

The following link shows the document he sent me.

Otaku PIR Circuit

{see comments on later post, pertaining to the USB sound cards.}
 

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Evil, Wicked, Mean, Nasty
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Discussion Starter · #5 ·
Here's what it looks like.



In this image from Otaku, the audio card (led lights, whatever) connect to the two wire terminal (green thingie). The pumpkin insert sensor wires are coming in from the left side of the image. His version has them connected to a fancy 3-wire connector on the board. I didn't have one handy, so I ignored that and soldered directly to the board.

The right side of the image shows wires going to a 9v battery connector.
 

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Evil, Wicked, Mean, Nasty
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Discussion Starter · #6 · (Edited)
I'm still hunting a few more talking pumpkin inserts in my area. (Hopefully my local make-n-take cohorts are ignoring this thread.) I had resisters, terminals, 9v battery connectors, and a couple of 7805s extra from my multiple voltage project. For me...this was a cheap solution. Especially considering I gained six free batteries and 10 superbright leds from two pumpkin inserts.

(Thanks to Otaku, Fritz, and Hedg for info on sensors.)
 

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Evil, Wicked, Mean, Nasty
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Discussion Starter · #7 ·

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These are a great solution. I've made a couple of them with the USB board and the RS PIR and they work great!
I usually record a 20 to 30 second clip and then add silence to the end of the 50 second recording. This gives me a bit of a delay before the audio can be re-triggered.
 

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Evil, Wicked, Mean, Nasty
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Discussion Starter · #10 · (Edited)

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I got one of the USB ones and piped it into an amp - I was actually very impressed with the sound - OK it ain't MP3 player quality but it is absolutely fine for most things. It ran a prop last year and was great but in playing around with it this year I think I've stuffed it up so need to order another few. It may just be the batteries though - I haven't got round to checking it.

I'm pleased with mine - well worth $10. Couple it to some cheap PC speakers.
 

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I got some of the 50 second boards. I like them, they are as loud as my gemmy's. My LR is 14 X28 with a 16 ft sun room on it. They can be heard from from one end to the other. I used one in my the RE gun I build and amplified that with a first small first amp. But I told someone on that thread. I thought They would be better used for close up sounds, if you are not going to amplify them. Like bugs in a cave, creaking door, back ground sounds. Basically sounds that would be outside of you ambiance sounds, that could be triggered at a certain point. As for the quality, No they are not as goo as a 40 dollar mp3. But you still need to amp the mp3 also and triggering is much harder for most people ( me) Also I went though lots machine gun sounds to find one I thought sounded really good. But I had played with some sounds from the 4shared files when I got the first board in. They seemed to be fine. The Ap8, or the boards from cowlacious are better options for a higher quality sound. But if you already have it check out the 4shared files.
 

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Got referred to this thread from Halstaff, and this seems to be a very good option. however I don't see that radio shack is carrying those anymore. Do we know of a suitable replacement or the key parts from it that could be bought from all electronics of similar?
 

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AE has this item:
http://www.allelectronics.com/make-a-store/item/PX-28027/PIR-SENSOR-BY-PARALLAX/1.html
but its pricey. There are PIRs available for ~$5 each that can be used in the circuit shown earlier in this thread. Keep in mind that the circuit doesn't have a lockout feature, so if the prop or device you're triggering can be reset by multiple sensor pulses you will have problems. If you're just triggering an audio board, many have a setting that prevents it being restarted while its playing the sound file.
 

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Sorry Forgedblades that I didn't give you the link to the unit they carry since the pumpkin inserts were a one time deal. Here's the one I was referring to that they carry in stock - http://www.radioshack.com/product/index.jsp?productId=12330342
Like Otaku mentioned, you can find them for less but these are easy for most people to get.
I have made this circuit up into a simple to build board that I've used for make and takes if you're interested in going that route.

 

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Forgedblades, definitely go with Halstaff's board if you want to use this triggering system. He sent one to me and they're super-easy to build and work perfectly.
 

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Halstaff & Otaku, I have contact steve at simple circuit boards and ordered 2 of the ones that Otaku had done for his entry in the 2010 $20 prop contest. IN addition he has a PIR trigger board with timer delay that I ordered to give me something that should work in hand. Going to give it a try to build a few on my own as well as The one in this thread as well. ( likely will come back with a few questions at some point) for now just waiting on parts to arrive.
 
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