Taking apart a Halco 89003 T8 LED lamp. Drawing up a schematic diagram of the internal power supply. And generally seeing how it’s put together. A fun little exploration.
I realize this is an older video. However, I have an interesting situation with my shop florescent 4 tube ceiling fixtures (six fixtures in all). Years ago I swapped out all the florescent bulbs with LED tubes. And all was well and projected great light. This past week one of those four tube LED fixtures went out. Thinking it would be extremely odd for all the LED tubes to go bad at the exact same time, I looked to the ballast that was still connected to them as the problem. I searched for replacement ballast until I realized you can take the ballast out of the circuit and wire the four LED tubes straight to the power coming in. I cut out the ballast and wired directly to the tubes with neutral to one end and power to the other. Since the four tubes were wired in parallel at each end (verified with DVM), I figured that was all I needed to do. However, the LED tubes didn't come on. Puzzled, I remove one LED tube and wired it direct to the wall outlet and again, nothing. All I would get was a flash of LEDs lighting for a split second and than nothing. There may have been a very faint glow that was almost impossible to see. I could get them to light for a very split second and than basically dead... Not sure what is goin on, but seem all the LED tubes are doing the exact same thing... I may have to tear one apart to investigate...
It depends on the type of LED tube. I think some of the first ones required ballast. I've seen some where the power goes in on one end and others on opposite ends. It could also be that when the ballast went bad, it destroyed the LED tubes.
I think this highlights the consumer don't fix it electronics world we now live in. These T8 tubes can be had online in Thailand for about a $1. Live at one end and neutral at the other and that is all you need; totally self contained. I rewired an old electronic fluorescent fitting to take a T8 today and just stripped out the old electronics and just wired it live at one end and neutral at the other. No point in repairing the electronics. Suppose I recycled the old fitting. How can they make them so cheap just amazes me and where does all this stuff go when it breaks and is thrown away?
yeah i went to their website and tried looking that ic up and couldn't come up with anything. these flash-in-the-pan companies come out of nowhere, make a bunch of shit and disappear, and we're all left scratching our heads for the next 20 years. are you sure about that marking? i went through quite a few datasheets, and it doesn't seem to quite "fit their pattern" of how they mark stuff. Could be a custom chip, too. you never know. i see you have 8 pins - is it that soic? or is it like a funny little qfn/dfn or something? i wouldn't think supervisor, since there's nothing to supervise. not a load switch, given the output to the next stage. might be a regulator, but the amount of current to drive that many leds doesn't jive with the regulators they have listed.. maybe overcurrent protection or monitoring?
It's an soic. I saw a datasheet of one of there other chips will a longer part number had package marking kinda like that. Well, it had an H and not an L. But the package marking was completely different from the part number. I kinda think not all of there chips have a datasheet available. It looks like over current protection. But why, if the regulator shorts out, it will blow the fuse. Unless they really don’t trust the fuses they are using. It was just a bit strange.
@@metalplasticelectronics354 Yeah, I'd have to say OC protection. It's probably just something they had to throw in to be able to sell it in countries with actual electric safety standards.
I realize this is an older video. However, I have an interesting situation with my shop florescent 4 tube ceiling fixtures (six fixtures in all). Years ago I swapped out all the florescent bulbs with LED tubes. And all was well and projected great light. This past week one of those four tube LED fixtures went out. Thinking it would be extremely odd for all the LED tubes to go bad at the exact same time, I looked to the ballast that was still connected to them as the problem. I searched for replacement ballast until I realized you can take the ballast out of the circuit and wire the four LED tubes straight to the power coming in. I cut out the ballast and wired directly to the tubes with neutral to one end and power to the other. Since the four tubes were wired in parallel at each end (verified with DVM), I figured that was all I needed to do. However, the LED tubes didn't come on. Puzzled, I remove one LED tube and wired it direct to the wall outlet and again, nothing. All I would get was a flash of LEDs lighting for a split second and than nothing. There may have been a very faint glow that was almost impossible to see. I could get them to light for a very split second and than basically dead... Not sure what is goin on, but seem all the LED tubes are doing the exact same thing... I may have to tear one apart to investigate...
It depends on the type of LED tube. I think some of the first ones required ballast. I've seen some where the power goes in on one end and others on opposite ends. It could also be that when the ballast went bad, it destroyed the LED tubes.
I think this highlights the consumer don't fix it electronics world we now live in. These T8 tubes can be had online in Thailand for about a $1. Live at one end and neutral at the other and that is all you need; totally self contained. I rewired an old electronic fluorescent fitting to take a T8 today and just stripped out the old electronics and just wired it live at one end and neutral at the other. No point in repairing the electronics. Suppose I recycled the old fitting. How can they make them so cheap just amazes me and where does all this stuff go when it breaks and is thrown away?
yeah i went to their website and tried looking that ic up and couldn't come up with anything. these flash-in-the-pan companies come out of nowhere, make a bunch of shit and disappear, and we're all left scratching our heads for the next 20 years.
are you sure about that marking? i went through quite a few datasheets, and it doesn't seem to quite "fit their pattern" of how they mark stuff. Could be a custom chip, too. you never know.
i see you have 8 pins - is it that soic? or is it like a funny little qfn/dfn or something?
i wouldn't think supervisor, since there's nothing to supervise. not a load switch, given the output to the next stage. might be a regulator, but the amount of current to drive that many leds doesn't jive with the regulators they have listed..
maybe overcurrent protection or monitoring?
It's an soic. I saw a datasheet of one of there other chips will a longer part number had package marking kinda like that. Well, it had an H and not an L. But the package marking was completely different from the part number. I kinda think not all of there chips have a datasheet available. It looks like over current protection. But why, if the regulator shorts out, it will blow the fuse. Unless they really don’t trust the fuses they are using. It was just a bit strange.
@@metalplasticelectronics354 Yeah, I'd have to say OC protection. It's probably just something they had to throw in to be able to sell it in countries with actual electric safety standards.