Velodyne switching PSU ?

[Pong Tsui]

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 some careful consideration. I was able to track down MUR1620CTRG and after rereading your post, I realized you may have done the same; although you list the part number as MUR1620CTA. Was this just a typo or was the original component on your board actually an ON Semiconductor MUR1620?

In any event, I mention this because the FEP16DTA (the original part on my board) description on Digi-Key website states the max current rating is 16A FOR EACH DIODE (the actual data sheet for this part does not distinguish if the 16A rating is for each diode or if it’s for both diodes combined) - please see attached screen shot. The MUR1620CTRG data sheet lists the max current for the device as 16A, which seems to be a match, however it states that this is a combined rating and that each diode only supports 8A. Could this explain why your power supply only lasted a few moments after installing Q3 and Q4 using the MUR1620?

Another difference between the FEP16DTA and MUR1620CTRG is Peak Forward Surge Current rating; the FEP is 200A while the MUR is rated at only 100A. I have not decided yet if this is significant or not and would welcome any thoughts. My initial guess is it is not significant, but will need to investigate further.

I also found another possible replacement for FEP16DTA using NTE6244, but it has very similar specifications as the MUR1620CTRG so may have same 8A vs 16A concern described above.

Would love to know more about your situation and if it has been fixed or if you learned anything more.

Yes fixed and found out the problem,the main point Q3= MUR1620CTG(common Cathode),Q4 = MUR1620CTRG(common Anode),
Please refer the U1=IR2153 circuit diagram

[Pong Tsui]

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 some careful consideration. I was able to track down MUR1620CTRG and after rereading your post, I realized you may have done the same; although you list the part number as MUR1620CTA. Was this just a typo or was the original component on your board actually an ON Semiconductor MUR1620?

In any event, I mention this because the FEP16DTA (the original part on my board) description on Digi-Key website states the max current rating is 16A FOR EACH DIODE (the actual data sheet for this part does not distinguish if the 16A rating is for each diode or if it’s for both diodes combined) - please see attached screen shot. The MUR1620CTRG data sheet lists the max current for the device as 16A, which seems to be a match, however it states that this is a combined rating and that each diode only supports 8A. Could this explain why your power supply only lasted a few moments after installing Q3 and Q4 using the MUR1620?

Another difference between the FEP16DTA and MUR1620CTRG is Peak Forward Surge Current rating; the FEP is 200A while the MUR is rated at only 100A. I have not decided yet if this is significant or not and would welcome any thoughts. My initial guess is it is not significant, but will need to investigate further.

I also found another possible replacement for FEP16DTA using NTE6244, but it has very similar specifications as the MUR1620CTRG so may have same 8A vs 16A concern described above.

Would love to know more about your situation and if it has been fixed or if you learned anything more.

Yes fixed,and found out the problem,the main point is Q3= MUR1620CTG(common cathode,
Q4= MUR1620CTRG(common Anode)
please refer the U1=IR2153 regulation circuit diagram

[mr_good_luck]

Re: Velodyne switching PSU ?

Good day, please see the capacity and voltage of the C15 capacitor in the power supply, it exploded, I can not understand what it was originally.

[sam_sam_sam]

Re: Velodyne switching PSU ?

all the capacitors are good, it's alive now, thanks guys

What did you do to fix it

[ds2010]

Re: Velodyne switching PSU ?

Good day, please see the capacity and voltage of the C15 capacitor in the power supply, it exploded, I can not understand what it was originally.

It is 22uF x 25V.

Can I please ask you for the favor in return (or anyone who has an access to this Power Supply board).

Can you please make a photo of the front of capacitor C9 (that blue HV cap) and post it here? It is charcoaled in my unit, and I need to find a replacement, but can't read a marking on it.

Or at least please re-type all text that appears on it.

Thank you.

[vladm74]

Re: Velodyne switching PSU ?

I fixed my SPS. Here are some recomendations and my board scematic.
1. You have to replace all the electrolytic capacitors even if they look good. Note that C7, C10, C12, C13 and C14 must be LOW ESR. At this step just remove them from the board and go to the next step.
2. Check MOSFETs Q1 and Q2. Replace both even if just one of them is bad. Check gate resistors R7 and R9 if your MOSFETs are shorted.
3. Check the diode bridge BR1 and all the diodes including zener D3 and D4.
4. Check the NTC mounted on radiator. It must be shorted.
5. After checking and replacing bad elements solder new capacitors.
6a. If you have oscilloscope, put 15V DC from any power source to U1 (+1pin, -4pin) and check oscillogram at pins 7(HO) and 5(LO). You are to see identical meandres. If not, replace U1 IR2153 and test again.
6b. If you don't have oscillascope and your MOSFETs was bad, replace U1.
7. Apply mains power. I highly recommend doing this through a 75-100W incandescent bulb. It will prevent MOSFETs from burning out.
8. Check all the voltages at the connectors J3, J4 and J5, and if they are ok, let it idle for a while watching there is no smoke or smell. Check the voltages again. Disconnect mains power.
9. I highly recommend to replace all the electrolytic capacitors on amp and pre-amp boards too. Especialy the two big ones on the amp board.
10. Connect amp and pre-amp to SPS and supply mains power through a incandescent bulb. You are to hear relay clicking. Check all the voltages again. Let it work for a few minutes watching there is no smoke or smell. Recheck the voltages.
11. If everythint is ok, assemble the subwoofer and check it.