# How To Give Your Wiper Motor Intermittent Control



## halstaff (Nov 18, 2009)

One of the projects I'm considering for this year is a wiper motor controlled hanging victim. However I didn't want him to run continuously but to turn on and off providing a more startling effect. I know I could have used a 2 stage timer or programed a Picaxe to do the job but thought all I really need is to be able to give my wiper motor an intermittent ability just like I have in my car. After finding a circuit online, I got to modifying it so that it would be more useful in a haunt setting. Now the circuit will run for about 9 seconds and has an adjustable off time controlled by the potentiometer. My hanging victim will scare even more TOT's now! Best of all it only cost about $7 to make.


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## niblique71 (Dec 2, 2009)

Brilliantly simple....(or so it seems) More details please


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## halstaff (Nov 18, 2009)

Simple and very useful (or so I thought).
Here's the diagram for the circuit I used. It originally had a 100uf cap which only allowed an on time of less than 2 seconds. By replacing it with the 470uf cap, I get around 9 seconds which is what I was looking for. The 68k resistor was originally a 3.3k but it seemed to work better for me this way.
Make sure and check the documentation for your transistors. My 2N4401 had the collector and emitter pins switched from the diagram. Needless to say it didn't work until I reversed mine. A rookie mistake I won't make again.


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## Otaku (Dec 3, 2004)

Nice application, Steve! I hate to mention it, but could an oscillator with a trimpot controlling the off time have worked for this prop? Using trimmers and switching diodes, you can build a 555 oscillator that has adjustable controls for both on and off times.


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## halstaff (Nov 18, 2009)

Otaku said:


> Nice application, Steve! I hate to mention it, but could an oscillator with a trimpot controlling the off time have worked for this prop? Using trimmers and switching doides, you can build a 555 oscillator that has adjustable controls for both on and off times.


That does sound like a better way to do it but this works for this application. 
I'm looking for an easy and inexpensive circuit to allow a wiper motor to be operated intermittently and this may not be the best solution. 
As you know, I don't yet have the knowledge to design a circuit like this from the ground up but have learned enough in the last year (thanks in a large part to you and Fritz) to adjust one a bit to make it do what I want it to. 
I'll be looking at ways to improve this and still keep the cost under $10.


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## halstaff (Nov 18, 2009)

I've had some requests for the parts list for this project so here it is -


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## ouizul1 (May 22, 2010)

That's excellent. I've got an old hanging person prop that this would be perfect for...thanks for sharing.


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