September 10, 20187 yr 2 minutes ago, plonkster said: That looks like a cheap SMPS to me (switch mode power supply). The power comes in and goes through a fuse and then 4 x 1N4007 diodes (rated at 1Amp each), so very clearly it's taking it to DC first. There is a varistor across it in that area (RV1?), which is a surge suppression device. It is difficult to say, but it looks like it is wired in such a way that if RV1 breaks down it will blow the fuse (as it did). Cheap SMPSes blow all the time. This might just be bad luck. I have boxes full of these things... whats the alternative?
September 10, 20187 yr Just now, Antony said: dead short on the 220 input circuit Remove the surge surpressor (RV1) and test if it is dead-shorted. For goodness sake throw it away and don't try to reuse it :-)
September 10, 20187 yr 4 minutes ago, Jaco de Jongh said: Firstly what is the total wattage of the LED's? the minimum wattage you can connect to this transformer is 35Watt Secondly, The output is 12 Volt Ac and the LED's normally operate on DC, please check the input requirements for the LED light , This is an Electronic Transformer, dont you see some flickering in the lights? I do see some flickering to be honest
September 10, 20187 yr 2 minutes ago, Antony said: whats the alternative? Buy a new one and see how long it lasts. Unless there is a pattern, this might just be bad luck. In my house I use good old iron transformers. Old school. Haven't had a problem even once. But the power factor sucks if you don't load them down properly :-)
September 10, 20187 yr 3 minutes ago, Antony said: I do see some flickering to be honest The transformer is not designed to drive the led's , I guess the others will fail as well, you are connecting to little load to this transformer and the output does not match the load. AC output, DC load.
September 10, 20187 yr 4 minutes ago, plonkster said: Remove the surge surpressor (RV1) and test if it is dead-shorted. RV1 removed and tested, Not short...
September 10, 20187 yr 15 minutes ago, Antony said: whats the alternative? A normal low volt lightning transformer or LED driver in the line of this Just ask your local electric wholesaler for a downlight transformer or LED Driver. They are quite cheap.
September 10, 20187 yr 1 minute ago, Jaco de Jongh said: A normal low volt lightning transformer in the line of this Just ask your local electric wholesaler for a downlight transformer. They are quite cheap. Perfect thanks... ps, are these LED bulbs polarity, because they are not marked at all. LED on left replaced the one on the right. ps, I'm thinking of wiring all 3 lights to one transformer.
September 10, 20187 yr This lamp is likely capable of being driven by AC. Note the little rectifier bridge inside.
September 10, 20187 yr 10 minutes ago, Antony said: are these LED bulbs polarity, Yes they must be, please take new picture of light on left with legs positioned as the light on right. I just want to see whats in there. Do you have a model number? 10 minutes ago, Antony said: I'm thinking of wiring all 3 lights to one transformer. It should work.
September 10, 20187 yr 3 minutes ago, plonkster said: This lamp is likely capable of being driven by AC. Note the little rectifier bridge inside. Wanted to check for that. In that case wire all three lights to one transformer first.
September 10, 20187 yr 4 minutes ago, Jaco de Jongh said: Wanted to check for that. In that case wire all three lights to one transformer first. Both sides (2 bulbs)
September 10, 20187 yr 7 minutes ago, Jaco de Jongh said: Wanted to check for that. In that case wire all three lights to one transformer first. ps... actual light switch contacts arced together. I had to strip it to "break" it apart. something weird happened.
September 10, 20187 yr 6 hours ago, Antony said: Both sides (2 bulbs) AC driven as @plonkster rightfully spotted. Use one of the remaining transformers and connect all lights to it. 30 Watt is closer to the Min rating than 10.. Should be a safer option . I am glad you posted the pics of the lights, I almost made you buy the wrong thing. If you need to replace, this will be an better option
September 10, 20187 yr 1 minute ago, Jaco de Jongh said: AC driven It almost looks as if "AC 12V" is printed inside on the PCB too :-) Edited September 10, 20187 yr by plonkster
September 10, 20187 yr 2 minutes ago, Antony said: ps... actual light switch contacts arced together. I had to strip it to "break" it apart. something weird happened. Its pretty normal for a dead short condition.
September 10, 20187 yr 2 minutes ago, plonkster said: It almost looks as if "12VAC" is printed inside on the PCB too :-) yep, you right.
September 10, 20187 yr 5 hours ago, Antony said: ps, are these LED bulbs polarity, because they are not marked at all. You could drive either lamp with AC or DC, the lamp on the right is pure resistance and will work with either voltage source, the LED lamp on the left has a diode bridge built in - it with rectify 12V AC to DC required for the lamp, with a DC source the bridge rectifier will swap it to the correct polarity for the circuit.
September 10, 20187 yr OK, all 3 lights containing 8 x 1.5 Watt LED bulbs each, (total 36 Watts) now wired to one 220V to 11.5V transformer (rated 36W to 160W, so I'm just inside the minimums... mmm..., something totally unrelated...minimums, minimums, minimums = GPWS) and all working fine + no flickering on the one light as was the situation before
September 10, 20187 yr 53 minutes ago, pilotfish said: You could drive either lamp with AC or DC Yes you could, connecting Dc to a rectifier will have the same end result as connecting AC to the same rectifier. I personally prefer to drive an AC rated device with AC and a DC rated device with DC... Eliminates confusion when the next electrician has to work on the device.
September 10, 20187 yr 10 minutes ago, Jaco de Jongh said: connecting Dc to a rectifier will have the same end result as connecting AC to the same rectifier. Wait before Commodore corrects me on this. The above statement is only true if you connect to a full wave rectifier. Trying that with a halve wave rectifier will yield a totally different result.
September 10, 20187 yr It will half work... It will pass power if correctly orientated and block power if not.
September 11, 20187 yr 11 hours ago, Jaco de Jongh said: Eliminates confusion when the next electrician has to work on the device. Just in case, I have labelled both the transformer and the wiring in the light to indicate 12V versus 220V
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