Light not functioning using power supply and relay


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Old 03-23-14, 07:57 AM
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Light not functioning using power supply and relay

Hey guys,

I have created a hockey goal light to be able to be set off using raspberry pi and an internet connection. The issue I have is that for some reason the light will not go off unless I start it, stop it, and start it again. The light it a Sentry Beacon that requires 4.2A @ 12.8 V (Sentry - Halogen Beacons | Federal Signal I have SY12) and I have a "Meanwell 12 Volt 100 Watt Ul Switching Power Supply 120 Volt Input Constant Voltage" to power the light which after I use the Voltage Adjustor I can get it to a max of 13.7 V. So the way it is all connected is I have positive wire coming from the light to the power supply. The negative from the light to a relay and then from the relay to the power supply. The relay is powered through the raspberry pi computer where it is also controlled.

Here is a quick video to show what I mean by starting, stopping, starting again. Goal light not functioning - YouTube

I will also attach to photos I have of the wiring, but not sure it will help.

Also that cardboard box is being changed out with a wooden one after I finish painting it. I will also try and post a higher quality video/pictures later, but I wanted to get this up as fast as possible for now.

Let me know what you think I need to do

Thanks in advance guys.
 
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Old 03-23-14, 11:11 AM
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Welcome to the forums.

Novel idea..... just one at the rink or will there be two ?

You need to break down what is happening..... or not happening. You have the pi controlling a relay and the relay controlling the light.

Is the pi always controlling the relay.....in other words.... is the relay always operating when you command it to ?

We'll assume that the relay is working every time you want it to. The relay closes but the light doesn't always start. A voltmeter at the power supply would confirm a power supply issue. When you connect that light to that supply.... that supply may see it as a dead short and go into shutdown. The voltmeter would confirm this idea.
 
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Old 03-23-14, 09:53 PM
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Thanks PJ. I will go ahead and confirm what the volt meter reads at every connection point and post the results tomorrow morning. It is just the one light and it is not for a rink... It's for my own use at home for when the Blackhawks score lol

Also to try to clear up what is happening is that upon first closing of the relay it will not rotate and emit light, if I use the pi to open the relay and immediately tell the pi to close the relay it will go off without an issue. This can be seen in the video I posted above. If I then wait another 5-7 minutes without closing the relay it will not run unless i close then open and then close again. Let me know if the video I posted does not work or is not clear.
 
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Old 03-23-14, 10:07 PM
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Have you got any big capacitors there..... like 4700 - 6800 mfd at 16vdc or better ?
Connect it across the + and - on the power supply. It sounds like the supply is going into protect.

That bulb and the motor in that light are presenting a dead short to the supply upon first power up.
 
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Old 03-24-14, 08:39 AM
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Ok so I just checked it out with the voltmeter.... When I check the reading before clicking the start program it reads 13.7 V on both the relay and the power supply unit. When I do the initial run where it hardly moves the power supply unit reads only .7 V and the green indicator light on the PSU is blinking. When I stop the program and restart it, it reads 13.7 V and the green indicator light is solid.

So I think you are right and it is protecting it or something, but how do I stop it from doing that? And I am unsure completely of what capacitor are inside of the unit. I bought it from amazon here is the link to the product I bought Amazon.com: Meanwell 12 Volt 100 Watt Ul Switching Power Supply 120 Volt Input Constant Voltage By Ledwholesalers, 3252-12v: Home Improvement

I am gonna go through their website to see if I can find what the indicator light is saying occurs.
 
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Old 03-24-14, 08:47 AM
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Ok so upon looking into the finer details of the product I bought (Meanwell Power Supply Products). You are right it goes into protect mode at 13.8V-16.2V. Even though I was only outputting 13.7V which is technically below the limit I think it was engaging the protect mode.... I put it down to 12.9V and now going to wait and see after it sitting for about 30 min if that solved the issue. I will let you know either way.
 
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Old 03-24-14, 09:32 AM
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Awesome PJ!!! it worked. All I had to do was reduce the Voltage to 12.9.

Thanks so much. Is there a way to close the thread and link a solution?
 
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Old 03-24-14, 04:15 PM
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Awesome...

No need to close the thread..... it will just slide off the pages and into the archives for anyone to read in the future.
 
 

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