# Extremely simple prop trigger - version 2



## Scary Papa (Jan 31, 2012)

EXTREMELY SIMPLE PROP TRIGGER - VERSION 2

In 2012 I posted a thread on using the Harbor Freight Driveway Alert to trigger sound activated props. Since that time I have used this driveway alert to trigger several of my Halloween props that are sound activated and it has worked reliably well. However, I also have several full size props that are not sound activated but instead are motion activated. As those of you who also have these types of motion activated props know, the factory motion sensors on these props do not work very well, especially in a haunt like ours that is outside, at night, in the dark, in the Haunted Forest. Here is the problem with these props. I will use my Headless Harry in this example.









Headless Harry is a really cool full size prop with this problem…









His motion sensor is located too low on the prop so sometimes it misses any motion, is subject to getting obstructed because of the location, and it will not reliably trigger if the motion is more than 3 ½ feet away from the motion sensor. Also, this motion sensor requires too much light to activate it. Something that is lacking in the Haunted Forest.

I wanted to use the Driveway Alert to trigger my Headless Harry prop but I did not know how to accomplish this. BobbyA solved this problem for me by suggesting using a relay in the wiring system of the driveway alert to trigger the prop through the “Try Me” button circuit. This setup worked beautifully. However, I kept thinking that there should be a simpler solution to this problem. This tutorial is the solution that I am now using to trigger my full size motion activated props. It still uses the Harbor Freight driveway alert as the basic trigger but uses only the sending unit part of the system. And with this setup my Headless Harry triggers every time up to a distance of 16 ½ feet and more and you can set the prop trigger anywhere you desire. The only limit is the length of the wire that you use to extend the sending unit LED light.

Now right up front I need to say that I did not come up with this idea. I saw the basic idea, I think, on this forum about a year ago but, unfortunately, I can’t remember who posted it. Since I do not want to take credit for any other members ideas I have tried to find the thread to give the proper credit for this idea but so far I have been unsuccessful. If anyone recognizes this idea and knows who first posted it please add that information to this thread. The member who posted it used it to trigger a small prop but I thought why would it not work on larger props as well. I modified the original idea somewhat and here is the tutorial on how I set it up to trigger my full size Headless Harry. It will work on my other full size, motion activated props as well.

MATERIALS NEEDED:









1.	Harbor Freight Driveway Alert (or similar)……..$10.99 on sale at Harbor freight
2.	Inline switch of some type. Either of these switches work well (Optional)
a.	Toggle switch…. $2.99 at Lowes (Optional)
b.	Roller switch….. $2.99 at Lowes (Optional)
3.	1 Male and 3 small gauge Female wire crimp connectors…..About $5.00 for a box of 6 each at Walmart (Optional only needed if you use an inline toggle switch)
4.	Small piece of 3/8” PVC tube……$1.99 for 5’ piece at Lowes
5.	9v battery….$4.99 for box of 2 at Walmart (your driveway alert may take 3 AAA batteries)
6.	Flat Black spray paint…….$0.99 at Walmart
7.	Small gauge wire (20/2 gauge or smaller would work best) These are examples of what you might use:

The white/black wire is speaker wire with the RCA plugs cut off……$6.99 for a 20’ set at Walmart
The roll of brown wire is $7.99 at Lowes for 25’ roll.
The blue wire with one white striped wire is speaker wire ……$7.99 per 25’ roll at Radio Shack
The black wire with the wall plug is a used 9V computer speaker power cord……$0.99 at our thrift store just cut off the transformer and the plug.
Or just use scrap wire you may have laying around……Free

Any small gauge wire will work but it needs to be 2 conductor and stranded. It helps to have one of the 2 conductors marked in some way so you can be sure to know what conductor is positive when you wire it up.

TOOLS NEEDED:









Small screwdriver
Wire strippers
Wire cutters
Wire crimpers
PVC tubing cutter or similar cutting tool
Small cutting tool to cut a notch in the sending unit case
Soldering iron/flux/rosin core solder (flux is really not necessary with rosin core solder)
Hot Glue Gun/glue
JB weld adhesive
Electricians tape (Optional – for insulating soldered electrical connections. Can use hot glue for this)

STEP 1:









Remove the Driveway Alert set from the box and set aside the receiving unit. You will not need the receiving unit for this project. Remove the screws holding the back of the sending unit to the front and separate the two pieces. Locate the LED light and identify the positive and negative wire leads to the LED light. The positive will be red and the negative will be black. 

STEP 2:









Cut the wires leading to the LED light. The LED light has a positive and a negative leg so be sure to leave enough wire on the light to designate which leg is positive.

STEP 3:

















Using the heat gun heat soften the glue holding the LED light to the front of the sending unit and remove the light from the case. Don’t apply too much heat or you will distort the case. Use just enough heat over short intervals to allow the LED light to be removed. This should take only a few seconds. Set the LED light aside for now.

STEP 4:

















Strip the insulation from the red and black LED light wires inside the case. Cut a short length of wire long enough to reach the back of the sending unit, about 6”. Using the wire strippers strip the insulation off the conductors on one end of this wire. Using the soldering gun/solder/flux solder the two wire conductors to the wire leads coming from the case. Make sure to note which conductor is soldered to the positive (red) lead and which is soldered to the negative (black) lead in the case. Cut any excess solder from the connection. The other end of this wire will be connected to 2 of the female crimp connectors later. In this example I used the white wire with a black stripe. The conductor with the black stripe I designated as the positive conductor.
Note: If you are not going to use an inline toggle switch you will not use a short wire with the wire crimp connecters but instead will need to use a length of wire that is long enough to reach directly from the sending unit to the motion sensor of your prop.

Also, if you do not want to solder the wire connections because you don't know how to solder or, like me, you are not good at it you can simply twist the wires together and instead of soldering the connection you can use hot glue to secure the connection. This is not as good as soldering the connection but it will work.

STEP 5:









If you are using an inline toggle switch separate and strip the ends of the conductors coming from the case. Using the crimping tool crimp a female connector on each of the bare ends. If you are using an inline roller switch or no switch skip this step.

STEP 6:









Using the glue gun/glue, separate and secure the soldered wires to the inside of the case. This will help secure the wires and also serve to insulate the soldered wire ends.

STEP 7:

















Now, using the cutting tool cut a notch on the side of the case to allow the soldered wire to come through to the outside. Put the case back together and then apply a dab of hot glue to the notch and wire to hold the wire in place. This will keep the wires from pulling out or disconnecting from the circuit board wiring. also, put a small dab of hot glue on the hole where the LED light was in the front of the sending unit. Allow time for the glue to cool.

STEP 8:









Using the hot glue gun/glue attach the toggle switch to the back of the case. Allow the hot glue to cool. The JB Weld may also be used for this if a stronger bond is desired. Attach the positive conductor from the case to one of the male terminals on the toggle switch.

STEP 9:









Take a length of wire long enough to reach from the sending unit to the prop motion sensor and strip the conductors on each end of the wire. Using the soldering iron/solder/flux, solder the LED light to the wire conductors on one end of the wire. Make sure to take note of which conductor is soldered to the positive side of the LED light. Use a small piece of electricians tape or a dab of hot glue to insulate the soldered connections.

STEP 10:









At the other end of this wire conductor crimp a female connector to the positive lead from the LED light. Crimp a male connector to the negative lead from the LED light.

STEP 11:

Plug the female connector from the sending unit positive lead to one male terminal of the toggle switch (if not already done). Plug the female connector (positive lead) from the LED light to the other male terminal of the toggle switch. The toggle switch should be inline on the positive conductors of the LED light. Plug the male connector from LED light (negative lead) to the remaining female connector of the wire coming from the sending unit.

STEP 12:









Now you will have a setup that looks similar to this one. Install the proper batteries in the sending unit, turn on the switch if one is installed and test the circuit. When you pass your hand in front of the PIR sending unit the red LED light should come on for a short time then go off. Test it two or three times.

STEP 13:









Cut a short length of the 3/8” PVC tubing. It should be about 1¼” long. Using the hot glue gun/glue attach this PVC tubing over the hole of the prop's motion sensor. You can use the JB Weld here if you desire a little more secure bond. After installing the battery in the sending unit with the switch off (or placing the sending unit turned away if no switch was used) insert the LED light into the tubing, turn on any switch used and test the set up to make sure it is working. I have found that if you just insert the light into the motion sensor hole without using the PVC tube it will not trigger the prop. But if you insert the LED light in the short piece of tubing it will provide more light to the sensor by reflecting light off the white interior of the tube and trigger the prop reliably every time.

STEP 14:









Spray paint the sending unit and the 3/8” PVC tubing flat black taking care to not paint over the window of the PIR sending unit. or the interior of the PVC tubing. Cover the window with tape prior to painting. When painting I suggest that you be sure to identify somewhere on the sending unit what channel the unit works on in the event you use other Harbor Freight Driveway Alerts in your haunt. Otherwise you might be triggering other props at the same time as well that might be working on the same channel. I leave a small clean area on the bottom of the sending unit and use a marker to write in the Channel number. Once the sending unit and PVC tubing are painted the setup is ready to go. Just insert the LED into the PVC tubing. When putting away the prop just retrieve the LED from the PVC tubing, secure the wiring, and store it away with the sending unit until its next use. Be sure to remove the 9v battery from the sending unit.

Here is a video of the prop working. For this demonstration I have not yet painted the sending unit or the PVC tube so it can be seen more easily. The prop is activated while I am 16 1/2 feet away from the prop. If you look closely you can see the LED light activated in the PVC tube when the sending unit detects movement.

https://www.youtube.com/watch?v=VGzLPfyRXXQ

NOTE: You do not have to use any switch in this setup. I use a toggle switch simply to be able to turn the system on and off as needed without having to remove the 9v battery from the sending unit. If you do not use a toggle switch but use the roller switch or no switch at all you should use one long length of wire to extend the LED light directly from the sending unit to the point where you want the LED light to be located at the motion sensor of the prop.

This setup is not a wireless setup as there will be a physical wire connection between the sending unit and the LED light at the prop motion sensor. However, you can make this truly wireless by using both the sending and receiving units and simply modifying the receiving unit by removing one of the LED lights from the receiving unit and extending the LED light with a length of wire as described in modifying the sending unit. In this case no modification would be required on the sending unit. You can then set the sending unit wherever you wish and when it is triggered it will activate the LED light of the receiving unit and the trigger the prop. You should, however, cut the wires to the speaker in the receiving unit or it will chime when the receiver is activated and you will also need to camouflage the placement of the receiving unit. For Headless Harry a good location for the receiving unit would be attached to the back of Harry’s rib cage under this shirt with the LED light wire extending down his pant leg to the motion sensor at the base of the prop.

An alternative to attaching the PVC tubing over the motion sensor at the base of the prop would be to open the base of the prop and locate the motion sensor inside. Cut a small hole in the top of the base and run the wire with the Driveway Alert LED light attached through the hole and in front of the prop motion sensor. Just remember, anytime you open a prop you must be careful to not disturb any of the mechanism that moves the prop.

This is a quick and easy setup. The total time to complete the project is about 45 minutes after all materials and tools are gathered together.


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## J-Man (Feb 1, 2011)

Nice job on the tut SP! Only thing I will add is using rosin core solder for any electrical work. A lot of those containers of flux have corrosive ingredients which will corrode electrical wiring and components.


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## Scary Papa (Jan 31, 2012)

Right you are, J-Man. I should have mentioned that. I am not really very good at soldering electrical components. I can just barely get it done. I did use rosin core solder but I also use the flux as I seem to get a better solder joint that way. Thanks for adding that information. I will add to use rosin core solder to the tool list.


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## J-Man (Feb 1, 2011)

Scary Papa said:


> Right you are, J-Man. I should have mentioned that. I am not really very good at soldering electrical components. I can just barely get it done. I did use rosin core solder but I also use the flux as I seem to get a better solder joint that way. Thanks for adding that information.


The trick to using rosin core is to heat the joint and then touch the solder to the joint and not the iron. If you touch the solder to the iron, it tends to burn off the flux before it has a chance to flow onto the joint. Give that a try and see if it works out better.


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## Scary Papa (Jan 31, 2012)

Thanks for the tip J-Man. That has actually been my problem when I don't use the flux. I kept having problems getting the solder to flow into the connection. This will be the fix I need to do a better job I bet. I will try it and see how I do.


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## MadCityHaunt (Nov 25, 2013)

Great tutorial Scary Papa and awesome tips on soldering you guys! One additional tip might be for forum members who don't know how to solder, you can always use those wire crimp caps as an alternative to soldering.









It's a good method for people who have been nervous about learning soldering and could be done with all the tools you have listed, with the addition of the caps.

Love stuff like this, thanks for the great tutorial!


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## AnCastor (Oct 22, 2020)

Hello,
I bought the motion sensor from HF. I have only sound activated props. 
Is it not possible to cut of the try me button and connect the two wires from the try me button to the sensor or the receiver. the button is only to close the circuit, not more.
I'm trying since 3 days, but I have no glue where my failure is, or if it will work. 
Hopefully someone can help me.


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## J-Man (Feb 1, 2011)

Well as you found out, that won't work. Use the HF unit as is by hiding it on the prop right where the pickup mic is.


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## AnCastor (Oct 22, 2020)

J-Man said:


> Well as you found out, that won't work. Use the HF unit as is by hiding it on the prop right where the pickup mic is.


@J-Man Thank you very much for the fast answer. But could you explain me, why it won't work? 
When the receiver get a signal from the sensor, the LED switch on, that means, the circuit is closed. Is it not possible to connect the two wires from the try me button to the LED?
Sorry for the questions, but I'll understand it. 
And is it possible to change the frequency? The driveway sensors have all the same frequency.


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## AnCastor (Oct 22, 2020)

In this clip you can see, that the guy cut off the speaker an connect it with two cables which are connected two a prop. Why doesn't work it for my props?


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## Scary Papa (Jan 31, 2012)

AnCastor said:


> Hello,
> I bought the motion sensor from HF. I have only sound activated props.
> Is it not possible to cut of the try me button and connect the two wires from the try me button to the sensor or the receiver. the button is only to close the circuit, not more.
> I'm trying since 3 days, but I have no glue where my failure is, or if it will work.
> Hopefully someone can help me.


AnCastor, welcome to the forum. I have the same issue with the one frequency alerts. But if you check the boxes there will be a sticker on the box that will tell you what frequency the alert works on. I eventually bought several on different frequencies. I think our local harbor freight carries about 12 different channels. As far as the trigger like J-Man said in his reply ...it just won't work. I thought it should work and I tried but never got it to work. The easiest way to use these on sound activated props as J-Man suggested is to simply put the receiver by the sound sensor on the prop. On my sound activated props I remove the litte pizio speaker from the receiver, add some wire between the receiver and speakers, and then put in line a 10 ohm resister. Then I glue the little speaker directly over the sound sensor on the prop. My headless harry works either on sound or PIR so in the tutorial I did in this thread I removed the light from the sending unit and put it over the light sensor on the prop. It works hubgreat. Good luck.


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## AnCastor (Oct 22, 2020)

ScaryPapa thank you for the answer. 
I tried the setup from the youtube video with another prop and it works. this prop have on/off/demo, what all of my other probs didn't have. 
I don't know what the internal setup of the demo is, but if I connect the two wires from the speaker with the two wires from the try me button it works.
In our HF they have 10 of the sets, but all with the same frequency. 
To aware that all of the props starting with on sensor, is it possible to connect the sensor to the prob and connect the two wires from the red LED with the try me button cables?


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## J-Man (Feb 1, 2011)

AnCastor said:


> @J-Man Thank you very much for the fast answer. But could you explain me, why it won't work?
> When the receiver get a signal from the sensor, the LED switch on, that means, the circuit is closed. Is it not possible to connect the two wires from the try me button to the LED?
> Sorry for the questions, but I'll understand it.
> And is it possible to change the frequency? The driveway sensors have all the same frequency.


Here is the short answer as to why it doesn't work. The Try Me connection on the prop requires a dry contact device, such as the simple button. The LED on the HF (or any LED circuit) is not a dry contact.


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## AnCastor (Oct 22, 2020)

J-Man is there an other dry contact in the HF circuit wich I can use?


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## Scary Papa (Jan 31, 2012)

AnCastor said:


> ScaryPapa thank you for the answer.
> I tried the setup from the youtube video with another prop and it works. this prop have on/off/demo, what all of my other probs didn't have.
> I don't know what the internal setup of the demo is, but if I connect the two wires from the speaker with the two wires from the try me button it works.
> In our HF they have 10 of the sets, but all with the same frequency.
> To aware that all of the props starting with on sensor, is it possible to connect the sensor to the prob and connect the two wires from the red LED with the try me button cables?


AnCastor, if you have props that will work with a light sensor you can actually use just the sending unit from the HF alerts using the system in my tutorial or from tutorials from others on this forum. Just open the sending unit, remove the light, add some wire long enough to reach from the sending unit to the prop light sensor, put the light over the prop light sensor and you will be good to go. J-Man and BobbyA have been great resources for me in more technical stuff.


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## AnCastor (Oct 22, 2020)

ScaryPapa, thank you for the answer. I haven't light señor trigged props. My props are all sound trigged.


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## Scary Papa (Jan 31, 2012)

Ok. I understand. Another suggestion for a neat prop are halloween projections. Might be a little late for you to do it this year but the projection especially the singing pumpkin projections from singing pumpkin.com have been the hit of our haunt for several years. You really don't have to buy an expensive projector.


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## J-Man (Feb 1, 2011)

AnCastor said:


> J-Man is there an other dry contact in the HF circuit wich I can use?


Go back to post #8 and do what I suggested.


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## AnCastor (Oct 22, 2020)

ok, thank you for your patio.
Now I'll do it like scary papa describe it in his post, I used the piezo speaker to trigger the props.
I cut the wire from the speaker and I connect a 10 Ohm resistor to mute the speaker. But the speaker is not mute. What can I do to mute the speaker?


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## AnCastor (Oct 22, 2020)

No one an idea?


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## J-Man (Feb 1, 2011)

AnCastor said:


> No one an idea?


You're contradicting yourself on this. First you said the prop in question would not trigger using the method in the video, now you are saying it will. So that brings up the next question, If you're using the speaker connections to trigger the prop, why are you leaving the speaker in? I believe the video says to remove it.


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## AnCastor (Oct 22, 2020)

Hello, sorry if I confused you with my posts. 
1. I want to use theHF to trigger my props without the speaker, only with the signal, that what I asked in my first posting. But I've learned this won't work.
2. Now I tried to mute the speaker and use the speaker to trigger the props. I connect a 10 Ohm resistor but the speaker isn't mute. And that was my last question.

Hopefully this will helps.


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## DaveintheGrave (Feb 12, 2004)

Great tutorial, Scary Papa!
I really need to try this!


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