On Saturday, 6 March 2021 23:17:06 GMT Tim wrote: > Its two lights and two power supplys (of which one power supply is > dead), both light work already tested with working power supply. Have > looked at the dead power supply (you can take it apart) but nothing > looks out of place.
Tim, I know nothing about fish tank lighting (the last time I kept fish was 30-40 years ago and I believe it had a fluorescent light). However, I do know a bit about electrics and electrical design. You can buy specialist power supplies for LEDs from places such as LED Hut https://ledhut.co.uk/search?type=product&q=+LED+Transformer but they tend to be expensive. We used a 60 W item from them back in 2016 for the model railway lighting (and it was half the price but wasn't dimmable). A quick search for LED Transformer on Google yielded lots of hits with prices much lower including: https://www.seratechnologies.com/shop/led-transformer-12v/ > The LED lights are just over 4ft long with three rows of LED's (it is a > 5ft fish tank) so I guess 47 watt was the design wattage. There is a > long lead from the light about 5ft and then a small pig tail from the > power supply which then screw together with a male female round three > pin plug\socket. There is a small pig tail of about 15" inches which is > hard wired to the Power supply for the 240v mains. I think that the three-pin plug may be a cheap and cheerful way of ensuring that the power can't be plugged in the wrong way round, but it's possible that the supply that you have monitors current draw and that is the sense wire. (It's also possible that the cable dates back to the time when the company's products were all powered directly from the mains (eg fluorescent or mains striplight) and they had to include earth.) If you have a multimeter, I would suggest buzzing all three pins out to see where they go (try both ends, eg lights to plug and plug to supply, to try to ascertain what the third pin is connected to. Apart from that, does the broken PSU (or light) have a brand name or Model Number? A search for that might provide a bit more information. -- Terry Coles -- Next meeting: Online, Jitsi, Tuesday, 2021-04-06 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
