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Discussion Starter #1
I want to be able to have an animated prop such as a grave grabber switch on for lets say 30 seconds and then be switched off for say 60 seconds, after that the prop turns on again.

Is this possible to achieve without the use of a controller or expensive software.

If so HOW ?

thanks in advance

Phil.
 

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Well, by the sound of it, you dont' seem to electonic savy...but a relatively easy and extremely cheap way of doing this is using an astable, 555 timer circuit hooked up to a relay. Using different resistor and capacitor values you could get somewhere close to the values you are looking for. However, 555 timer circuits aren't usually too useful for anything over a minute. You could do this easily for about $5....depending on where you buy the components. The diagram for the circuit is here...

http://freespace.virgin.net/matt.waite/resource/handy/pinouts/555/

(it's the one at the bottom labeled "astable")

As far as something already built, and cheap, I'm not really sure. You could always fork over the dough and purchase a boobox or something of the sort. If you decide to attempt the 555 timer circuit, I could help if you need it.

Understanding electronics and being able to create your own, can go a long way in any halloween setup and save you money. I would suggest attempting to create this simple circuit.
 

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Timer kits are plentiful and cheap. This one:

http://store.qkits.com/moreinfo.cfm/MK111

would just need to have the potentiometer on the "pulse" timer changed to a higher value, likely the same value as the "pause" potentiometer, to get the times you want for your prop. Run the power for the prop through the relay (Common and NC) and you're done.
 

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Discussion Starter #6
Thanks guys for all your great responces. I've decided to go with Otaku's idea.


Hallloween13 thanks for all the info on the 555 circuit, I will defiantly give that a go as we should be working with 555 circuits in school next year. Hopefully i will understand them more and will be able to use it for a prop :D
 

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Discussion Starter #9
Hey guys just wanted to update you on my progress, i also have some more questions ;)

So as promised i have got round to making a 555 circuit, its only on a breadboard right now but it works. My questions are, how do i get this circuit permanently onto a PCB ?? I've tried twice before and both of the circuits haven't worked, so what is it im doing wrong ??? I would also love you guys if someone could tell me how i proceed to connect a prop to the timer.

If it helps at all, this is the pcb board im using http://cgi.ebay.co.uk/5-x-Vero-Styl...Supplies_ET&hash=item19bbd15c19#ht_1165wt_911

Thanks

Phil :D
 

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I'd start with checking the solder joints. Whenever I've assembled a non-working timer, it turns out to be a bad junction. For your application, a kit really is the easiest way to go. You don't have to sweat the components, just drop 'em in and solder it up. With minor changes to customize the timing intervals, you can have your prop up and running very quickly.
Regarding your timers that aren't working - do you have a schematic?
 

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Discussion Starter #13
Hey Otaka unfortunately i don't have a schematic, this is because i followed this video and i have no idea how to read a schematic.

Im going to give building the circuit on a PCB one more shot, and i will double check all of the solder joints on my previous attempts. Do you have information on how i would connect a prop to the timer, as right now i only have a led to represent the prop ???

Thanks

Phil :D
 

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You'll need to replace the LED with a relay. To choose the correct coil voltage for the relay, assume ~2VDC will be lost in the circuit. If you're using a 12VDC power supply, you'll wind up with about 10VDC at pin 3 on the 555. You can verify the voltage with a DMM. This is sufficient to power most 12VDC relays. If you're using 9VDC for power, a 5VDC relay would work. You probably have a resistor between pin 3 and the LED - don't forget to remove that when you install the relay. Connect the coil terminals to pin 3 and ground. Connect the prop and it's power source (in series) to the Common and Normally Open pins on the relay. When the relay fires, the prop will activate. This is where those kits come in handy - most of them include a relay that can switch 2 - 5 amps. If you can post clear pics of your circuits (top and bottom of the board) I may be able to help with the troubleshooting.
 

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Phil, I would also suggest you install a diode across the relay coil to protect your circuit from the collapsing field of the relay. The side of the diode with the white line would go toward the pin 3 side of the 555, if I am not mistaken, the others on here can check me on this. Keith
 

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Good advice, Keith. Helps protect the 555 from damage. And yes, the ring side of the diode goes to pin 3. A 1N4148 diode will do the job.
 

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See, I hang out here long enough and I am learning things.... thanks. Keith
 

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Discussion Starter #19
So i need to get a 5vdc relay and a diode, this is probably a stupid question but the diode goes from pin 3 to where exactly. Sorry if im sounding completely stupid its just electronics is fairly new to me but i want to learn more, which is why i would prefer not to just buy a timer kit.

Otaku here are two pictures of my attempt at the timer.
View attachment 13077

View attachment 13078

Thanks

Phil :D
 

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Phil, the diode actually attaches across the coil of the relay. One side of the relay is going to go to pin 3 the other side is going to go to ground. So you could, in essence, wire the diode from pin 3 to ground and achieve the same results. Just remember that the lead with the white stripe on the diode has to solder to the lead going to pin 3 for it to work. Also, pay close attention to the coil current required to energize the relay. You do not want the 555 timer to try to source too much current. I believe the limit is 50mA, once again, Otaku probably knows this number more exact than I do. Hope this helps, Keith
 
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