Re: Velodyne SMPS, power transformer
Possibly or it could be that it just was not clear enough from what was written for me to avoid incorrectly thinking the rectifiers are the same. In any event, I have already posted this key point (that they are in fact different) in the other thread titled “Velodyne switching PSU ?“. Not sure if the folks contributing to that particular thread are still actively pursuing a solution, but I felt it was important to add this info there just in case they are or in case someone else working on the same board come across the thread. Hopefully...
PlayerOne
Member
Last Activity: 03-19-2024, 06:02 PM
Joined: 03-22-2020
Location: NY
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Re: Velodyne SMPS, power transformer
Thanks again, will get the parts on order and let you know how things work out once they’re installed. Hope you have a great Easter if that’s something you celebrate.Leave a comment:
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Re: Velodyne SMPS, power transformer
Sorry didn't see your question...U1 is IR2153 (attached photo of original part as well). My understanding is this switches the power transformer at frequency set by resistor and cap connected to it (probably 100Khz), but doesn't actually control the output voltage, correct? It has some feedback to control duty cycle only?...Leave a comment:
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Re: Velodyne switching PSU ?
One thing to look out for is that Q3 and Q4 rectifying diodes are not the same part number...Q3 is common cathode and Q4 is common anode. I made the mistake of thinking they were the same and blew C7 after replacing both Q3 and Q4 with the common anode configuration. Thankfully R_J (forum member) was able to spot the error. Hope you were able to get your ps running again, but wanted to pass this along just in case.
BTW, I noticed on the front page ‘Features’ part of the data sheet of my originally installed Q4 diode...Last edited by PlayerOne; 04-12-2020, 10:15 AM.Leave a comment:
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Re: Velodyne SMPS, power transformer
R_J, can't thank you enough for catching that...you are absolutely correct. One of them is in fact common cathode. This would adequately explain C7 blowing, no?
Attached is a photo of the original parts, which I do not believe are available any longer...at least not that I could find. Another thread on this forum regarding the same SMPS mentioned the MUR6120 being used and its data sheet looked comparable.
Attached both data sheets as well to see if you agree MUR6120 is suitable replacement (there's also a version...Leave a comment:
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Re: Velodyne SMPS, power transformer
Yes, the capacitance value and max voltage rating for C7 and C10 match the originals. Would it be OK for me to remove C7 and C10 in order to be able to trouble shoot? I’m finding it difficult to take measurement when the supply only lives for several seconds before popping C7.Leave a comment:
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Re: Velodyne SMPS, power transformer
One of the other thoughts I had was that all I did was recreate the original problem, which was finding C10 blown. Perhaps this time it was just C7 that happened to blow first.Leave a comment:
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Re: Velodyne SMPS, power transformer
Thanks, much appreciated...will check and double check. I was very careful to make sure I got the cap polarity correct for each cap that was replaced. C7 and C10 where both brand new components purchased from DigiKey and a reputable brand (Nichicon)...even so, not impossible to get a faulty part...although unlikely. C7 was definitely domed, but C10 looks to be in good condition with no sign of looking bad, although looks can be deceiving.
Do you have a pinout for the transformer? I can’t find any info on it and would love to...Leave a comment:
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Re: Velodyne SMPS, power transformer
U2 has been removed and has 36k ohms between pin2 (ground) and pin 3 (output)...same as that measured on the brand new component so looks normal. Pin 1 (input) to pin 3 (output) measures 8M ohm, which is same as the new component as well. Conclusion is U2 is still good and not cause of C7 blowing when power was applied.
Was hoping U2 was going to be clearly bad, but now I’m back to square one...not sure what’s going on.
Any thoughts greatly appreciated!Leave a comment:
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Re: Velodyne SMPS, power transformer
Replaced Q1&Q2 FETs, Q3/Q4 rectifier diodes, all electrolytic caps (except for C24, next to J3, and C2, C3 big caps on hot side). Replaced 3A main fuse and tried to power it up...after several seconds, cap C7 (one of the large caps one the cold side) blew and vented smoke while leaking its electrolytic fluid out. Not good. I checked all discrete diodes with Fluke 87 meter in diode mode and all were good (roughly 0.4v to 0.5vdc).
The ‘event’ did not seem to fry any of the components replaced above...FET’s resistive...Leave a comment:
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Re: Velodyne SMPS, power transformer
Thanks, appreciate your guidance. I suspected the same since it switches the FETs and ordered a replacement along with the FETs, rectifier diode arrays (common anode) and replacement caps.Leave a comment:
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Re: Velodyne SMPS, power transformer
Ok thanks, will probe around on components connected to FETs. Could this have lead to one of the big caps (C10=330uf, 100v) on the cold side to have blown or do you think the two diode bridges (Q3 and Q4, MUR6120CTRG, common anode) connected to secondary are also suspect?
Have FETs on order...thanks again!Last edited by PlayerOne; 03-31-2020, 08:30 PM.Leave a comment:
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Re: Velodyne SMPS, power transformer
Thanks again...Post #6 updated with the resistive measurements requested..please let me know if I’ve misunderstood. My best guess is FETs are bad, bridge is good.Leave a comment:
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Re: Velodyne SMPS, power transformer
FET (Q2) has 0.5ohm between G and S and same between G and D. It has 0.3 ohm between D and S...guess that's considered a short?
FET (Q1) has 1.3ohm between G and S and same between G and D. It also has 0.3 ohm between D and S...guess that's considered a short too?
The part number of Q1 and Q2 are both FPD12N50.
Bridge rectifier (BR1) has 0.54V across each of the 4 diodes using multimeter set to test diodes..part number KBL406. I'm thinking this part is OK, no?...Leave a comment:
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Re: Velodyne SMPS, power transformer
Just upload more photos of top and bottom of board. One of the big caps (C10) was completely blown has been replaced along with it’s twin next door. See photo of C10 after having been replaced...powering the board still causes main 3A slow blow fuse to open.
What do you see looking a the underside traces? There are what looks to be some bare spots showing copper runs in some key areas as well as a few spots that look to have been hand worked to add more solder (not by me)....Last edited by PlayerOne; 03-31-2020, 07:37 PM.Leave a comment:
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Re: Velodyne SMPS, power transformer
Thank you...appreciate the quick reply. I don't suspect the transformer is bad, but trying to recreate enough of schematic to help with trouble shooting the PS. Coming up empty on the transformer is making that difficult.
Thanks again...will be back shortly with pics of top and bottom of board....Leave a comment:
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Velodyne SMPS, power transformer
I need help in finding a schematic or otherwise identifying the electrical characteristics of a transformer in a SMPS having the following marking:
042-010214-000ZR
ELY 1317
A photo of the transformer is attached. In particular, this is a PCB mounted transformer and I need the pinout.
I've tried Google searches of various portions of the part number with no luck, however managed to find posts with photos of this transformer having the same markings, except for the numbers following the “ELY” which leads me to believe they must be date code... -
Re: Velodyne switching PSU ?
Here's a photo of the C10 capacitor before it was replaced; a pretty impressive...well...explosion.
...cap stuffing all over the place. Also attached a photo of it once it was removed. Both of the 100v caps have now been replaced so that part of the board is good to go. Still working on figuring out what else is wrong and reviving the power supply....
Leave a comment:
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Re: New Members - please post your introductions here
Ummm...Hello Everyone! Ok, we'll that wasn't so hard
Joined the board hoping to learn from the experience of others who share the need to tinker, fix things that need fix'n, yes to save some $, but much more importantly to tackle a challenge and figure things out for the fun of it.
I've been away from electronics for a very long time and a non-working SMPS from a Velodyne subwoofer was just the thing to re-ignite my interest. Check out my latest posts on that project if you'd like and of course...Leave a comment:
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Re: Velodyne switching PSU ?
Is the problem now fixed? I’m still working on mine and waiting for replacement components to arrive before I can continue.
One thing I discovered is my original Q3 & Q4 FEP16DTA common anode rectifying diodes (marked on the TO-220AB case as being manufactured by Fairchild Semiconductor...Fairchild is now ON Semiconductor) is now an obsolete component. The obsolescence notification letter that was published at the time lists the replacement component as ‘none’ so finding a suitable replacement requires...Last edited by PlayerOne; 03-29-2020, 09:22 AM. Reason: Added screen shot photo from Digi-Key websiteLeave a comment:
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