electonic incense of the bad kind

[reible]

I was out working in the shop today when one of my florescent lights started flickering. These are relatively new T8 with electronic ballasts. It did that for less then a minute before going dark. About then I could smell the incense so I pulled the switch and got the fixture down and outside to stink up out there for a while.

This is the first one of these to have that happen out of my collection. I had been thinking about replacing some of them with LED's so this might get to be my first one.

I'll pull this one apart and see if I can see anything like a wire that had shorted or such but my gut feeling is that it is dead so pulling the electronics and rewiring might well be in order. I'll have to order those type bulbs since the ones I have are just the replacement for the tube types....

Anyway maybe time to call it a day now.

Ed

[skou]

Ed, you let the "Magic Smoke" out.

I think that everyone knows, when
something electrical is made, they
put in "Magic Smoke," Once you
let that smoke escape, it's history!

( )

steve

[reible]

So, want to see what was inside? I did.

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Ed

[skou]

Ed, which component on the first
board looks like it released the
Magic Smoke? I'm thinking the
red-brown disc cap, next to the
(yellow colored) transformer.

There are the 2 can looking
electrolytic caps, the xformer,
and that disc cap in the area.

steve

[reible]

Ed, which component on the first
board looks like it released the
Magic Smoke? I'm thinking the
red-brown disc cap, next to the
(yellow colored) transformer.

There are the 2 can looking
electrolytic caps, the xformer,
and that disc cap in the area.

steve

I don't see any components that look damaged but the heat was concentrated in the area of the cap and x-former. I may solder suck a few parts just out of general interest but I'm not planning on attempting a repair.

What I do plan to do is isolate the pads where the hardware is for the bulbs and reuse them by way of wire. The LED bulbs will be here in a day or so and I want to have this fixture ready to go. But then I have a large list of things I want to do today so we will see if it happens today or tomorrow.

The LED tubes have the ability to work with or our without the ballast and they are more 4.5W better without. It is just a matter of getting power to the two ends and adding the switch back in, with the isolation the parts can just sit there and look pretty.....

Ed

[charlese]

The only failures of electronic circuits I have witnessed were due to "cold solder joints". The connection becomes weak and with temperature changes actually the connection is open, causing arching and resulting failure of the "attached" component.

[reible]

The only failures of electronic circuits I have witnessed were due to "cold solder joints". The connection becomes weak and with temperature changes actually the connection is open, causing arching and resulting failure of the "attached" component.

Ah such a sheltered life. Parts do fail and it is not uncommon for caps to go as the fit rate on them can be a lot greater then other components. This is especially true of electrolytic types.

Anyway I did pull the components and as you can see there was a bit of heat up when it happened. The lead on the capacitor is just gone........ board scorched.

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I was having so much fun I pulled all the parts on both boards after this. I then wired up the sockets for the LEDs. Next time I'll just cut traces to isolate the sockets but I will only do a couple of them for testing purposes. I have 4 bulbs arriving tomorrow so this will be test 1.

Here are just a couple of shots of the wiring.

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The bulbs are shunted internally pin to pin or so I read. If not I'll have to add another wire.....

I didn't take any other pictures and unless you have the same lamp as I do I'm not sure if more pictures would be of any help.

Ed

[reible]

Bulbs arrived but they were not shunted so a few tweaks to my wiring. Not a big deal and now I know for next time.

The bulbs I got have the clear shield so you see the row of LEDs and I think they may have a little bit more output.

The watt meter says between 34 and 35 watts, package say 18+18 = 36 watts. That is very minor savings if any, I'll isolate one of the old fixtures and measure that.

Light output is another matter. I got a phone app and check the old florescent fixture above the workbench. No other lights on and sitting at work bench height I got a reading of 496 lux, the new LEDs had a reading of 796 lux!

Ed

[Ed in Tampa]

What tubes did you use? Where did you order them?
If I read this right you are saying you are getting more light from the new tubes, is that correct?

[reible]

What tubes did you use? Where did you order them?
If I read this right you are saying you are getting more light from the new tubes, is that correct?

I got the 4 pack of these to try out:

https://www.amazon.com/gp/product/B01C5 ... UTF8&psc=1

I picked there because of the color temperature(6000K) and the fact they are clear. The pricing is odd on these, $9.86 per bulb in the 4 pack then goes to $10.50 for the 12 pack and then to $9.95 for the 24 pack. So the cheapest per tube is in the 4 pack.

Yes a lot more light! I don't necessary trust the number from a phone app but it is clearly brighter and about 1.6x or so from a comparison of those numbers.

Ed