Repairing My Light Chaser

One of the components of the lighting setup is my trusty old PAR light chaser which I built from a kit back in 2002. It simply sequences 4 lights (80W PAR Flood Lights) either via an oscilator or via music. I have always loved this chaser because it's simple, rock solid and it fills a room with light. It was pretty much the single effect I could count on...

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This chaser drives 2 custom light boxes with 4 x 80w coloured PAR floods in each that can be stood up or stacked horizontal. I have a DMX controlled switch that switches on/off the chaser unit at the required times so it's "part" of the computer controlled system now.

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The light boxes were very old and chipped and had a long 4 x 10m cable hanging out of them which was starting to show signs of wear so I decided to rebuild the boxes and replace the cable with IEC power plugs making it much easier to store and transport the boxes. 

The rebuild was simple and only took a saturday afternoon and about $35 of wood and paint then a further few hours to solder up the new plugs. I tested each light individually before using the chaser and all tested out fine. 

I connected everything to my chaser to test and started up my lighting system. As soon as I kicked in the chaser... Click... The breaker tripped on my power block cutting everything off. I disconnected the light boxes and thinking I must have wired something wrong I tested every bulb and connection and again, everything was fine. I connected everything together again and tested... Click... Again the breaker went. 

After much confusion and testing things one at a time I discovered the issue. The IEC power leads I was using (kettle plugs as many call them) which I have about fifty of the things, one of them had the Active/Neutral pins around the wrong way. I checked every lead I had and all followed the proper wiring standard except a single one which essentially caused a complete short between Active and Neutral when connected to the light box (Luckily I use a breaker switch for my setup). This could have been much more serious had I used that lead on an amp or a light and electrocuted myself or a client! 

While I was glad to find the issue it wasn't without problem. The short on the output of the chaser killed one of the channels causing it to lock completely ON. Luckily I still had the manual from when I built it and after looking at the circuit I figured there was only one component that could have gone faulty and that was the driving triac for the 240v output.

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I was able to source a replacement from my local electronics store ($4) and replace it within 15 minutes which had it all working good as new. Again one of the reasons I love this chaser is it is simple to maintain. 

While I was a little pissed I lost an entire night troubleshooting and fixing this issue I was actually very glad I found the defective lead amongst my equipment. The lead was not to standards and could have been very dangerous being in the reverse polarity. I was also happy I found this issue during my tests and not during a live show and had I not had electronics or technical knowledge I would have been out of pocket on a new chaser. 

I learned a pretty valid lesson and that is simply to check your equipment and leads thoroughly. I will do another check before I put everything away again to make sure it's all wired the same way. 

Last modified on Wednesday, 04 May 2016 09:08

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