Thanks Jerry, I am using this to charge a 48v nominal LiFePO4 battery pack, so push it over 55v and replaced the single package with two as you did. This is a great supply for my purpose, I can use it to top balance the individual cells and charge the full pack at decent amps. I have the S800-65 and the S800-70 versions of the switching supplies and both have the same circuit. My S800-70 has a little daughter board for fan speed control, but I just fitted a Noctua fan and didn't bother with more speed control. The Noctua is great, even at full speed it's noticeably quieter and still moves air. I also have the newer RD6018 and I haven't found a good 1200W supply for it yet, tried a cheap Lincoa brand from China, but would not recommend it. Noticeably poorer quality than the one in the kit and much louder fan.
Thank you! It's nice to see that the fix is pretty simple. I doubt I'll ever be in a situation where I'm pushing this at full power, but if I do I know what I need to do to avoid a potential issue. The environment I'm in is already somewhat noisy, so I can't really hear the switching supply fan at idle or full speed.
I agree with your theory on junction temperature. That particular package and screw hole mount for the diodes is not optimal for dissipating the heat being generated. What you want is pressure on the package directly above the the device inside the package. Not a simple task to achieve ! A bar across the device and then two outboard screws works well, but it is difficult to judge what is sufficient torque on the screws before braking the package.
So, the original kit comes with a power supply which can’t do the full 60v and this on comes with a supply that can’t do the full 12A. They are consistent, you’ve got to admit!
It can do both, just not at the same time :) The good news is that it has now been running at 12.1A and 61V for 10 hours. Thats 738W or almost 1HP so with the addition of a £3.00 diode it seems to be able to meet the spec but I would still recommend a higher power supply (the 1KW version is probably the same unit with 2 diodes fitted).
It is fairly common for them to have multiple positions where they do a higher power unit on the same PCB or they can use 2 derated parts. By the way I always during 1st power up use my variac which is fed via a 200VA isolating transformer because of the reason you said, limited power so a bang is not so loud or destructive.
I actually think this unit was designed to be fitted with more than one of these diodes but they tried to skimp and decided to fit just one. First power up was using the variac but it cannot handle the power for this supply so for full power testing it was connected directly to the mains.
@@JerryWalker001 Yes mine with only 200VA transformer is only the initial proving power up. :), just to make sure I have not done something stupid during the repair.
Thanks Jerry for all the great videos. I do have one question; I noticed in part 1 you said you would not use the load resistor but in part 3, I see you did add the load resistor, why?
The videos in this series actually spanned several days of testing and part of that was to fit the resistor. The information that came with the kit said that it would reduce noise at low power settings so I wanted to test it. It did not make any difference to what I was showing in the video (and very little difference to noise which I am still testing and may post a video on at some point). I ended up removing it as it made no real difference and increased the standby power but was present for some segments that made it into the videos.
@@JerryWalker001 hello, I am expecting a similar equipment in a few weeks. I find your videos informative, and I will possibly need to deal with the low tension use 'while the alim is 18A) here is a video where I noticed the tricks I tell you in another video ruclips.net/video/SgkFuSv3Uug/видео.html . some shielding, I plan to make a crowbar for low tension uses (just to avoid surges in case of wrong charging) thanks for exchanging your experience (ande sorry for my english!)
So far I haven't seen a truly stress test on the Riden6012 itself because of a minimal drop-off between Vin and Vout has been performed. However, I would say that if you maintain the maximum supply voltage while operating at a lower one but at the maximum operating current per the manufacturer's specification. It would be a different outcome.
So please confirm: Running full 12 amps at 12 or even 24 volts (not the max of 60) and it should be able to do that all day long with the stock diode, correct? I'm also very looking forward to your future fan mod. I've temporarily added a 100 ohm pot to the fan, but it's a sub optimal solution for a maddening loud fan. And I'm the one who asked about the location of the temp probe, so thanks for going into that in part 3...clever location. Looking forward to part 4 Jerry and thank you! I plan to do some of your mods.
I think that anything under a total of approx 550W total output power would be fine but above that the time should be limited (down to zero at 720W). I will be modifying the fan control as I find it annoying. It runs when the unit is 'off' unless the switch on the back is also in the off position but when the supply is on the bench rack it is not easy to reach so I want the fan off when in standby.
@@JerryWalker001 I totally agree about the fan. It's almost like the fan sensor on the PCB you heated up needs some big calibration or something. Ideally it'd start up initially, then slow down to a purr or stop until the temp rises and is needed.
hi Jerry, I enjoy and learn from your videos a lot. I wonder, could you consider making a video about noise testing and supression on these cheap supplies like S800-70. How one could go about figuring out where the noise comes from, reducing it and measuring the effect. I have two S400-xx supplies powering my RD PSU and they induce noise in the circiuits they are not connected to. Just by turning them on scope trace gets three times fatter. I tried to add resistors to switching FETs gates but I fail to relaiabli measure any effect. I'm not asking to debug my problem but that kind of topic would be especialy interesting to me. By the way, KP184 has host/slave feature. I assume by connecting RS485 pins on the back and selecting one load for host and another for slave you may be able to use host interface to control both loads at a same time. Have you tried it? I got only one of these so I just can say that selecting host mode, in system menu, actually sends data out. Thanks for you videos ;)
Thanks for taking the time to make this video, I appreciate your efforts! Do you have a manufacturer/part number for the steering diodes, and who did you source them through?
@@JerryWalker001 Thank you sir, I just now tried to find it, however, this p/n mur30CT60 doesn't seem to find me anything searching on several websites including Farnell. I wonder if we could somehow find a cross-reference to another brand, to find a suitable match.
Seems like the p/n was a bit encrypted hehe. This one looks more like the one: MUR3060CT ...Attempting to find it now, thanks. EDIT: Found them on AliExpress...
@@samsonite8017 Pretty sure I already told you this on the DIYsolar board, but if you are in the USA and don't want to wait for a slow boat from China, these worked for me (and I ran it for 3 hours at full output): smile.amazon.com/gp/product/B07J4MHSJ5/
@JerryWalker001 can you tell me please what resistor you put on the PSU DC output? Does this help to get rid of the wining noise if the PSU runs on idle?
Hi Jerry, excellent videos - really insightful! Hope you don't mind me asking, but I'm having terrible trouble trying to source the diodes (mur3060nct) in the same TO3 package. RS/Farnell/Rapid etc all turned up blanks. All I can find is the much smaller ct version. I'd very much welcome any suggestions please.
So you recommend the rd6018 version of the back end PSU right? Cause I was going to buy the full package as you did which comes with the Rd6012 version.
Great video series! I bought an S-1200-65 power supply to use with RD6018. There are 6 dual diode P/N LXDC4 UA4030G, which I can't find a replacement, or data sheet for. There are also two extra unpopulated locations on the board for two more of the same parts. If anybody knows an alternate part, I'd be interested in hearing.....
Hi Jerry. Turning this potm does not adjust the fan speed. I contacted Riden and Riden told it is for current adjustment, not to be touched by the customer.
@@daveton3895 I never said it adjusted the fan speed. It sets the fan threshold which I said was a current output. If you seem my modification I do Not say this should be adjusted and my modification is to control the fan using the current output of the connector. I also never suggested that this pot should be adjusted. It was someone else that made that suggestion.
Yes as long as the back ends are isolated. The outputs will be fully floating so you can tie them together however you want. In a recent video I connected 2 of them in series to give 0-120V.
Hi Jerry, 2 questions if you don't mind. I see you mounted the fan directly on to back of the S12A case. Did you cut of the back-plate of the S800-70? that plate is in the way to be able to do that. I think, your way of mounting will indeed improve cooling. Do you recommend to leave the cover off the S800-70 when you close the S12A case? This will impove airflow, right? There is a blue multiturn pot 5Kohm S1R1 near the fan connector. do you know what can be adjusted? Some fan control? Thank you for the info on the hottest part of the S800-70. Great job you did all that testing and measured that. I will stick my sensor with thermo-conductive glue directly onto the middle leg of one of the diodes . my fan runs at 2 speeds 9Volts and 14,6V when sensor is hot. This fan is probably a 12V model.? you 100% right, That control indeed needs improvement . Tx again
Yes I cut the rear off the supply. See this video ruclips.net/video/y_TAnfTYa6I/видео.html I attached both the supply sensor and the RD6012 sensor to the rectifier heatsink. I left the cover off the supply and everything works fine now and does not get too hot. The pot is used to adjust the supply output voltage and I set mine to 67V
Hi Jerry, just for your information , I had ordered a second S800-70, but received a S800-65. This seems now to be the recommended PS. by Riden and for use with the RD6012. The fancontrol circuit is different . Standard off , high temp full. I am using for the S800-70 my own buck XL7015, the standard pcb, to control my fan. I use this module with a 10k NTC , This module supplies at 30C 4.2V and at around 70C 12V to the fan. The fan in the S880-70 is a quality fan I can mail you more details in case you are interested.
@@daveton3895 I checked the specification for the 800-65 and I think it is the same supply as the 800-70. Itis specified as a 'custom' edition' so I think they have simply adjusted it to 65v to reduce the power output. Also the temperature control pot may have been altered. If this is the case then it will most likely still fail at full power.
05:34 Yes and no. I have opened the enclosure., cannot return it. Some modification on the pcb as well . An outputcap was replaced with a 10W resistor, Bad decision .More heat less capacitance. For a 12A output, capacitance is very small now with 25% less capacitors , very poor solution.
Yes I used the same type of diode as I wanted to prove that it was the use of double diodes that cured the issue and not a different type. I will not try 3 diodes unless it fails again as the diode capacitance is getting close to the switching recovery limit so another diode may cause the switching device to overheat and fail. It has been running for over 6 hours at full power now without failing and so it seems to be cured.
@@krzysiekstanski to say the truth, mine is working well just the way I use it, so I am not planning on doing those just yet. And about the actual performance I'm afraid I'm not qualified to answer those questions (I'm just a seasonal hobbyists). I think Jerry will be more qualified to answer that
Did you just leave the existing jumper in place? Looks like theres a spot to run a jumper to each diode. The flyback transformer is noisy in mine compared to yours
Hi Jerry, what is the mains input current and power in when you run it at full power or say at 500watt output power? I measured for 500 watt output power already 4.3 amps at 225V AC. ? Is that not too high?
It depends on how you measure it as the SMPS that came with the kit has a poor power factor. I did quite a lot of testing of the supply efficiency and it came out around 91% at full power (This rose to almost 93% after the modification). Output from the SMPS was 835W (69V x 12.1A) which was 726W output from the RD6012 (60V x 12.1A). This gave an input power from the mains of 918W. The peak current for a power factor of 1 would be 4.1A (at 225V) but it will be much higher than that in practice because of the poor power factor. Also of course make sure you are measuring true RMS and bear in mind that if you are using a variac then it will introduce a lot of distortion which will further push up the apparent peak power.
@@JerryWalker001 Hi Jerry, Thank you for the quick reply. Yes indeed the peak current will be a lot higher. I measured the amps with a analog Amp meter, the best what I can afford at this moment and no Variac. I like to monitor the current, Just do not want to blow up the switching transistors at the input. I do see the Riden DPS series in one of your video's . Must be a good design, when you use those! Do you use extra cooling.? I am thinking of getting the DPS8005.
@@daveton3895 I do not use extra cooling but these supplies are only used for low current testing. I supply them all from isolated DC supplies so they are all floating. I use them when I need multiple independent supplies. They are also not enclosed so they stay fairly cool. Analog meters give good approximations of true RMS so they are good for this application. Peak currents will be very high but the best method is to measure efficiency as this should show up any big issues.
Yes it was the only failure, I did quite a lot of investigation into this which I did not show in the video. Looking at the impulse currents flowing through the device showed that at powers above around 480W it was being operated outside its rating. The junction temperature would have been getting way too high and no amount of heatsinking would resolve this. Putting two in parallel resolved this and because the allowable peak current is a function of junction temperature then this resolved the problem in my supply. I have used it a fair amount since I modified it and have had no further problems. It is also worth dropping the output voltage to around 67V instead of 70 as this lowers peak power output from 847W to 810W and this helps to keep the junction temperatues down.
I quite like the meanwell supplies, but I don't know of any 70v ones. Just around 60 for the 48v with adjustable voltage which should be sufficient for 99% of all cases. And they are nearly all isolated, so you could use 2 in series.
Thanks Jerry, I am using this to charge a 48v nominal LiFePO4 battery pack, so push it over 55v and replaced the single package with two as you did. This is a great supply for my purpose, I can use it to top balance the individual cells and charge the full pack at decent amps. I have the S800-65 and the S800-70 versions of the switching supplies and both have the same circuit. My S800-70 has a little daughter board for fan speed control, but I just fitted a Noctua fan and didn't bother with more speed control. The Noctua is great, even at full speed it's noticeably quieter and still moves air. I also have the newer RD6018 and I haven't found a good 1200W supply for it yet, tried a cheap Lincoa brand from China, but would not recommend it. Noticeably poorer quality than the one in the kit and much louder fan.
Thank you! It's nice to see that the fix is pretty simple. I doubt I'll ever be in a situation where I'm pushing this at full power, but if I do I know what I need to do to avoid a potential issue.
The environment I'm in is already somewhat noisy, so I can't really hear the switching supply fan at idle or full speed.
I guess Im quite randomly asking but does anyone know of a good site to watch new tv shows online ?
@Eden Jaxon Flixportal xD
@Jeremy Jaziel thanks, signed up and it seems like they got a lot of movies there =) Appreciate it!
@Eden Jaxon You are welcome :)
Very informative videos about riden 6012 looking forward to the modification of the fan I'm expecting home my device this week
I agree with your theory on junction temperature. That particular package and screw hole mount for the diodes is not optimal for dissipating the heat being generated. What you want is pressure on the package directly above the the device inside the package. Not a simple task to achieve ! A bar across the device and then two outboard screws works well, but it is difficult to judge what is sufficient torque on the screws before braking the package.
Nice to know the fix is easy. Seems the engineers designed it sanely and then somebody cheaped out in production.
So, the original kit comes with a power supply which can’t do the full 60v and this on comes with a supply that can’t do the full 12A. They are consistent, you’ve got to admit!
It can do both, just not at the same time :) The good news is that it has now been running at 12.1A and 61V for 10 hours. Thats 738W or almost 1HP so with the addition of a £3.00 diode it seems to be able to meet the spec but I would still recommend a higher power supply (the 1KW version is probably the same unit with 2 diodes fitted).
It is fairly common for them to have multiple positions where they do a higher power unit on the same PCB or they can use 2 derated parts.
By the way I always during 1st power up use my variac which is fed via a 200VA isolating transformer because of the reason you said, limited power so a bang is not so loud or destructive.
I actually think this unit was designed to be fitted with more than one of these diodes but they tried to skimp and decided to fit just one. First power up was using the variac but it cannot handle the power for this supply so for full power testing it was connected directly to the mains.
@@JerryWalker001 Yes mine with only 200VA transformer is only the initial proving power up. :), just to make sure I have not done something stupid during the repair.
Thanks Jerry for all the great videos. I do have one question; I noticed in part 1 you said you would not use the load resistor but in part 3, I see you did add the load resistor, why?
The videos in this series actually spanned several days of testing and part of that was to fit the resistor. The information that came with the kit said that it would reduce noise at low power settings so I wanted to test it. It did not make any difference to what I was showing in the video (and very little difference to noise which I am still testing and may post a video on at some point). I ended up removing it as it made no real difference and increased the standby power but was present for some segments that made it into the videos.
@Jerry Walker Thank You! I hope you and your family stay safe.
@@JerryWalker001 hello, I am expecting a similar equipment in a few weeks. I find your videos informative, and I will possibly need to deal with the low tension use 'while the alim is 18A) here is a video where I noticed the tricks I tell you in another video ruclips.net/video/SgkFuSv3Uug/видео.html . some shielding, I plan to make a crowbar for low tension uses (just to avoid surges in case of wrong charging)
thanks for exchanging your experience (ande sorry for my english!)
So what dual-diode package number did you end up using? Are they the same part number?
@Andrew Kaison - Where are you watching Flixzone, since I don't see it on Roku?
So far I haven't seen a truly stress test on the Riden6012 itself because of a minimal drop-off between Vin and Vout has been performed.
However, I would say that if you maintain the maximum supply voltage while operating at a lower one but at the maximum operating current per the manufacturer's specification. It would be a different outcome.
So please confirm: Running full 12 amps at 12 or even 24 volts (not the max of 60) and it should be able to do that all day long with the stock diode, correct? I'm also very looking forward to your future fan mod. I've temporarily added a 100 ohm pot to the fan, but it's a sub optimal solution for a maddening loud fan. And I'm the one who asked about the location of the temp probe, so thanks for going into that in part 3...clever location. Looking forward to part 4 Jerry and thank you! I plan to do some of your mods.
I think that anything under a total of approx 550W total output power would be fine but above that the time should be limited (down to zero at 720W). I will be modifying the fan control as I find it annoying. It runs when the unit is 'off' unless the switch on the back is also in the off position but when the supply is on the bench rack it is not easy to reach so I want the fan off when in standby.
@@JerryWalker001 I totally agree about the fan. It's almost like the fan sensor on the PCB you heated up needs some big calibration or something. Ideally it'd start up initially, then slow down to a purr or stop until the temp rises and is needed.
hi Jerry, I enjoy and learn from your videos a lot.
I wonder, could you consider making a video about noise testing and supression
on these cheap supplies like S800-70. How one could go about figuring out where
the noise comes from, reducing it and measuring the effect. I have two S400-xx
supplies powering my RD PSU and they induce noise in the circiuits they are not
connected to. Just by turning them on scope trace gets three times fatter. I
tried to add resistors to switching FETs gates but I fail to relaiabli measure
any effect. I'm not asking to debug my problem but that kind of topic would be
especialy interesting to me.
By the way, KP184 has host/slave feature. I assume by connecting RS485 pins
on the back and selecting one load for host and another for slave you may be
able to use host interface to control both loads at a same time. Have you
tried it? I got only one of these so I just can say that selecting host mode,
in system menu, actually sends data out.
Thanks for you videos ;)
Thanks for taking the time to make this video, I appreciate your efforts! Do you have a manufacturer/part number for the steering diodes, and who did you source them through?
They were mur30CT60 and I purchased them from Farnell
@@JerryWalker001 Thank you sir, I just now tried to find it, however, this p/n mur30CT60 doesn't seem to find me anything searching on several websites including Farnell. I wonder if we could somehow find a cross-reference to another brand, to find a suitable match.
Seems like the p/n was a bit encrypted hehe. This one looks more like the one: MUR3060CT ...Attempting to find it now, thanks. EDIT: Found them on AliExpress...
@@samsonite8017 Pretty sure I already told you this on the DIYsolar board, but if you are in the USA and don't want to wait for a slow boat from China, these worked for me (and I ran it for 3 hours at full output):
smile.amazon.com/gp/product/B07J4MHSJ5/
@JerryWalker001 can you tell me please what resistor you put on the PSU DC output? Does this help to get rid of the wining noise if the PSU runs on idle?
Nice mod/analysis/video ,,, my tune was "the magic roundabout".
Excellent ! I did not watch all along at first . Could a better fan be used with less noise ?
I just swapped the fan for a Noctua and it makes a big difference.
Hi Jerry, excellent videos - really insightful! Hope you don't mind me asking, but I'm having terrible trouble trying to source the diodes (mur3060nct) in the same TO3 package. RS/Farnell/Rapid etc all turned up blanks. All I can find is the much smaller ct version. I'd very much welcome any suggestions please.
So you recommend the rd6018 version of the back end PSU right?
Cause I was going to buy the full package as you did which comes with the Rd6012 version.
Great video series! I bought an S-1200-65 power supply to use with RD6018. There are 6 dual diode P/N LXDC4 UA4030G, which I can't find a replacement, or data sheet for. There are also two extra unpopulated locations on the board for two more of the same parts. If anybody knows an alternate part, I'd be interested in hearing.....
I can't find that PN either. I have two RD6018's and considering that PSU
Hi Jerry, the other potmeter, I mean the multiturn blue potmeter at the primairy side of this supply , not the one to adjust the voltage.
That pot adjusts the fan threshold.
Ok Tx I will adjust that. need full speed to come in at lower temp.
Hi Jerry. Turning this potm does not adjust the fan speed. I contacted Riden and Riden told it is for current adjustment, not to be touched by the customer.
@@daveton3895 I never said it adjusted the fan speed. It sets the fan threshold which I said was a current output. If you seem my modification I do Not say this should be adjusted and my modification is to control the fan using the current output of the connector. I also never suggested that this pot should be adjusted. It was someone else that made that suggestion.
@@JerryWalker001 misunderstanding there. I did not touch this pot. Tx
Can you tie 2 of these supplies together so you can have, say: +15 & -15 ?
Yes as long as the back ends are isolated. The outputs will be fully floating so you can tie them together however you want. In a recent video I connected 2 of them in series to give 0-120V.
@@JerryWalker001 - Thanks Jerry
Hi Jerry, 2 questions if you don't mind. I see you mounted the fan directly on to back of the S12A case. Did you cut of the back-plate of the S800-70? that plate is in the way to be able to do that. I think, your way of mounting will indeed improve cooling.
Do you recommend to leave the cover off the S800-70 when you close the S12A case? This will impove airflow, right?
There is a blue multiturn pot 5Kohm S1R1 near the fan connector. do you know what can be adjusted? Some fan control?
Thank you for the info on the hottest part of the S800-70. Great job you did all that testing and measured that. I will stick my sensor with thermo-conductive glue directly onto the middle leg of one of the diodes .
my fan runs at 2 speeds 9Volts and 14,6V when sensor is hot. This fan is probably a 12V model.? you 100% right, That control indeed needs improvement
.
Tx again
Yes I cut the rear off the supply. See this video ruclips.net/video/y_TAnfTYa6I/видео.html
I attached both the supply sensor and the RD6012 sensor to the rectifier heatsink. I left the cover off the supply and everything works fine now and does not get too hot. The pot is used to adjust the supply output voltage and I set mine to 67V
Hi Jerry, just for your information , I had ordered a second S800-70, but received a S800-65. This seems now to be the recommended PS. by Riden and for use with the RD6012. The fancontrol circuit is different . Standard off , high temp full. I am using for the S800-70 my own buck XL7015, the standard pcb, to control my fan. I use this module with a 10k NTC , This module supplies at 30C 4.2V and at around 70C 12V to the fan. The fan in the S880-70 is a quality fan I can mail you more details in case you are interested.
@@daveton3895 Thanks for the information, Maybe they saw the video :)
@@daveton3895 I checked the specification for the 800-65 and I think it is the same supply as the 800-70. Itis specified as a 'custom' edition' so I think they have simply adjusted it to 65v to reduce the power output. Also the temperature control pot may have been altered. If this is the case then it will most likely still fail at full power.
05:34
Yes and no. I have opened the enclosure., cannot return it. Some modification on the pcb as well . An outputcap was replaced with a 10W resistor, Bad decision .More heat less capacitance. For a 12A output, capacitance is very small now with 25% less capacitors , very poor solution.
great video. Did you use same diode as original one ? And you use 2 of them , not 3 ? will be working with 3 ?
Yes I used the same type of diode as I wanted to prove that it was the use of double diodes that cured the issue and not a different type. I will not try 3 diodes unless it fails again as the diode capacitance is getting close to the switching recovery limit so another diode may cause the switching device to overheat and fail. It has been running for over 6 hours at full power now without failing and so it seems to be cured.
@@JerryWalker001 It remains to find where to buy such diodes, the only place for now is China ... MUR3060CT can it be replaced with MUR3060WTG?
@@st.alexiev625 MUR3060PT is similar at least from the datasheet. As for if it is suitable or not I'm not qualified to answer that question
@@gilegue6693 could the use of more powerful diodes (eg MUR6060PT) improve something?
@@krzysiekstanski to say the truth, mine is working well just the way I use it, so I am not planning on doing those just yet. And about the actual performance I'm afraid I'm not qualified to answer those questions (I'm just a seasonal hobbyists). I think Jerry will be more qualified to answer that
What does the blue pot near the fan connector do?
Did you just leave the existing jumper in place? Looks like theres a spot to run a jumper to each diode. The flyback transformer is noisy in mine compared to yours
I left the jumper so that the diode pairs were in parallel.
@@JerryWalker001 Thanks for the reply this was a good fix for a couple of my power supplies
Hi Jerry, what is the mains input current and power in when you run it at full power or say at 500watt output power? I measured for 500 watt output power already 4.3 amps at 225V AC. ? Is that not too high?
It depends on how you measure it as the SMPS that came with the kit has a poor power factor. I did quite a lot of testing of the supply efficiency and it came out around 91% at full power (This rose to almost 93% after the modification). Output from the SMPS was 835W (69V x 12.1A) which was 726W output from the RD6012 (60V x 12.1A). This gave an input power from the mains of 918W. The peak current for a power factor of 1 would be 4.1A (at 225V) but it will be much higher than that in practice because of the poor power factor. Also of course make sure you are measuring true RMS and bear in mind that if you are using a variac then it will introduce a lot of distortion which will further push up the apparent peak power.
@@JerryWalker001 Hi Jerry, Thank you for the quick reply. Yes indeed the peak current will be a lot higher. I measured the amps with a analog Amp meter, the best what I can afford at this moment and no Variac. I like to monitor the current, Just do not want to blow up the switching transistors at the input.
I do see the Riden DPS series in one of your video's . Must be a good design, when you use those! Do you use extra cooling.? I am thinking of getting the DPS8005.
@@daveton3895 I do not use extra cooling but these supplies are only used for low current testing. I supply them all from isolated DC supplies so they are all floating. I use them when I need multiple independent supplies. They are also not enclosed so they stay fairly cool. Analog meters give good approximations of true RMS so they are good for this application. Peak currents will be very high but the best method is to measure efficiency as this should show up any big issues.
Hi Jerry, was the mur30CT60 the only component which failed in your S-800-70V powersupply? It indeed heats up quickly I measured its case temp 100C +
Yes it was the only failure, I did quite a lot of investigation into this which I did not show in the video. Looking at the impulse currents flowing through the device showed that at powers above around 480W it was being operated outside its rating. The junction temperature would have been getting way too high and no amount of heatsinking would resolve this. Putting two in parallel resolved this and because the allowable peak current is a function of junction temperature then this resolved the problem in my supply. I have used it a fair amount since I modified it and have had no further problems. It is also worth dropping the output voltage to around 67V instead of 70 as this lowers peak power output from 847W to 810W and this helps to keep the junction temperatues down.
@@JerryWalker001Super ! Will parallel 2 diodes and drop the voltage as you suggest. Tx for the great advice!!!
danke
Anyone have suggestions on alternative power supplies from decent manufacturers ? 70v is not an easy one to find.
I quite like the meanwell supplies, but I don't know of any 70v ones. Just around 60 for the 48v with adjustable voltage which should be sufficient for 99% of all cases.
And they are nearly all isolated, so you could use 2 in series.