High ambient temperature LED  - Page 1
Forum section: electronics / projects

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: September 07, 2015, 09:15:59 am
content: Hi, been asked to design an LED board that operate in an oven with 80°C, while i found LED good enough to run in such environment and a power-supply ELG-100-C from Meanwell (can operate at 90°C) am still sceptical about a power supply that will survive long working period in that temperature, will that shorten capacitor life time in it am pretty sure they are not some cheap cap in there but what are the chances that those things will pop up too soon.

author: coppice
author_rank: Super Contributor
timestamp: September 07, 2015, 09:29:16 am
content: I can understand why you would need to put lights in a hot place, but why would you make life hard by putting their power supply in the oven with them?

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: September 07, 2015, 09:41:15 am
content: don't get it either ... i asked to same question, they asking for it to be like that , those light are replacement for some old light so AC cable are in there already. Am not sure if they can make any hack inside the thing or how easy to access those wires. but even if they can am still interested to know what are the risks.Edit : it's a huge oven, a room size oven.

author: Jeroen3
author_rank: Super Contributor
timestamp: September 07, 2015, 11:01:27 am
content: Tell them the prices of psu inside and psu outside. They'll turn.

author: MikeW
author_rank: Regular Contributor
timestamp: September 07, 2015, 11:31:48 am
content: Beware that 90°C is the Tcase max temperature, not the maximum rated ambient temperature.I would be surprised if you could sit that in an 80°C oven, switch it on and not exceed the Tc.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: September 07, 2015, 12:04:34 pm
content: Quote from: MikeW on September 07, 2015, 11:31:48 amcan't agree more.however this psu will be attached to a metallic structure 1.5m / 0.15m / 0.3m so i was thinking how safe will it be to consider that this will be enough to maintain case temperature between that range of 80° to 90°C

author: MikeW
author_rank: Regular Contributor
timestamp: September 07, 2015, 12:17:13 pm
content: I would have thought that if it's an oven then there would be insulation outside the metallic structure though?

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: September 07, 2015, 01:17:15 pm
content: The metallic structure am talking about is the led fixture itself not the oven so no insulation outside of it.

author: ruffy91
author_rank: Regular Contributor
timestamp: September 07, 2015, 01:30:56 pm
content: Why even bother about LEDs? The power they save will be used by the oven because the heating power from the bulbs is missing :-). And at 80 degrees celsius or even higher the efficiency from LEDs will be very low.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: September 07, 2015, 01:43:12 pm
content: there is a saying in my country " they sell the monkey and they laugh at the own who buy it " that's what marketing ppl doyou asking the wrong man why they need LEDi mean if everytime someone came to an EE and say ... hey i need that thing that do stupid stuff can't you do it for us , and we say why bother we will be out of business you know