RuiDeng Riden RD6006 DC power supply

[Cliff Matthews]

Did anyone do anything about noise?

I think if you watch his subsequent video, it's not nearly that high. Some YouTubers also measure much less.

[pantelei4]

RD6006 has a large output voltage ripple when switching loads 5A, setting current limits 6A.
Oscillograms of the transient process with a periodic connection of a resistance of 5 ohms with an output voltage of 25V.

[RetiredHobbyist]

Hmmmm. When I try to open the file via multiple avenues they all tell me it's not a valid rar file. Am I clicking on it wrong? Wonder if the software is useful. I'll never know.

[BravoV]

All RuiDeng needs is to start developing newer type that with linear pre-regulator, assuming they have decent analog designer to make a good one while reasonably cheap.

RuiDeng actually had an active official representative here, too bad got banned as couldn't refrain not to keep spamming their product here again n again in this forum.

[yesyes]

Hmmmm. When I try to open the file via multiple avenues they all tell me it's not a valid rar file. Am I clicking on it wrong? Wonder if the software is useful. I'll never know.

I have the same problem. I can't find a version that even installs. Not too bothered though as I doubt I will ever need to control my PSUs from a computer. Graphing of some values would be nice though.

[RetiredHobbyist]

I was finally able to acquire the rar file with my Android device and open it. Copied the contents to my PC and installed it. I was able to launch the program so I guess I'm good.

[elektrolitr]

I also had the problem with .rar file not opening and it was solved easily by updating 7ZIP to the latest version.

[RetiredHobbyist]

WinZip couldn't open it either. No matter. Now the so-called usb driver seemed to install but doesn't recognize the psu. Next problem I need to solve. Is this really worth it?

[ironcurtain]

Right after connecting the 60v PSU I got from Banggood:

https://imgur.com/a/7lDBeLT

It's a goner. It did bang well, though. Ugh.

[dsc5555]

I always wondered why the called it Banggood. Now we know!

[RetiredHobbyist]

I used a data cable and now works fine. yay

[BlackFX]

It looks like the module itself isn't a huge source of noise, if fed with a linear supply it's actually pretty good

[Cliff Matthews]

It looks like the module itself isn't a huge source of noise, if fed with a linear supply it's actually pretty good

Enjoyed the video (duly subscribed as well)
It really would be fair (for all those who bought the switching back-end) to see the same capacitor bank used to filter out it's noise.  Perhaps 1 or 2 NTC thermistors could be used to gracefully power-up that many caps?

[BlackFX]

It looks like the module itself isn't a huge source of noise, if fed with a linear supply it's actually pretty good

Enjoyed the video (duly subscribed as well)
It really would be fair (for all those who bought the switching back-end) to see the same capacitor bank used to filter out it's noise.  Perhaps a varistor could be used to gracefully power-up that many caps?

I am quite tempted to give it a shot on mine once I have the USB interface repaired. I'll do a write up once I do

[thm_w]

It looks like the module itself isn't a huge source of noise, if fed with a linear supply it's actually pretty good

Can you quote some specific loads and p-p ripple voltages please?
In the other thread I measured <160mV at 5Vout 5A peak (full BW), with the actual ripple being much lower. Dave measured ~100mV p-p at 6A.

If I limit bandwidth to 20MHz then I see a bit less than what Dave did, 80mV p-p at 6A 5V out. But my source PSU is only 30V, so that may be the reason.

I'm not convinced my source PSU is adding significant noise to the signal, these switching spikes are entirely from the RD unit. I have not watched your video yet though to see what supply you are using.

[BlackFX]

It looks like the module itself isn't a huge source of noise, if fed with a linear supply it's actually pretty good

Can you quote some specific loads and p-p ripple voltages please?
In the other thread I measured <160mV at 5Vout 5A peak (full BW), with the actual ripple being much lower. Dave measured ~100mV p-p at 6A.

If I limit bandwidth to 20MHz then I see a bit less than what Dave did, 80mV p-p at 6A 5V out. But my source PSU is only 30V, so that may be the reason.

I'm not convinced my source PSU is adding significant noise to the signal, these switching spikes are entirely from the RD unit. I have not watched your video yet though to see what supply you are using.

Thats not my vid - just one I found on youtube

He was seeing I think 6v p-t-p at 58v/6a (I think he made the same mistake as Dave initially so his readings are 10x off) on the SMPS, and then 300mV p-t-p with the linear supply. If he is off by a factor of 10 as Dave was at first, then his measurements should probably be 600mV and 30mV respectively. I am a total n00b when it comes to measuring the high frequency noise like this - so I could be talking out my ass

[Cliff Matthews]

@BlackFX - Thanks for the link anyway, these things are getting popular. In my post I mentioned a varistor feeding a cap bank that sits between both smps's (that should have been an inrush limiter, so the back-end doesn't shut-down on start-up) 

What are the chances both SMPS's are interacting with each other to produce these results?

[BlackFX]

@BlackFX - Thanks for the link anyway, these things are getting popular. In my post I mentioned a varistor feeding a cap bank that sits between both smps's (that should have been an inrush limiter, so the back-end doesn't shut-down on start-up) 

I am thinking that I will just use a current limiting resistor on the input and then shunt it with a relay once the bank is charged.

What are the chances both SMPS's are interacting with each other to produce these results?

That seems entirely plausible to me

[BlackFX]

Okay, I am a bit dumb - can someone explain to me what the hell is going on here.

61v of potential between my scopes ground and the (output off) ground on this supply.

Photo attached.

[AlexFerro]

Earlier in the thread yesyes was talking about how they appear to use a low side switch to disconnect the output, rather than a high side switch.
So you are probably seeing a little bit of leakage from the input voltage to that terminal, and measuring that. I don't have mine in front of me at the moment, otherwise I'd test that myself.

Hi,
I would like to get back to this question:

- If I buy 2 of these and connect them to the same AC-DC PSU, can I connect their GNDs together so that I can, for example, have 5V and 12V supplies with common ground? Is the input GND the same as the output GND?

I have now received 2 of these PSUs and a 48V 10A PSU to feed them both. I'm still not sure that I can use the 2 outputs with common GND. I measured resistance between the input and output GNDs of one PSU and I get just over 8Mohm. So it seems that the input GND is not the same as output GND. Before I try connecting both output GNDs and set fire to it (I don't have an explosion containment pie-dish  ) can someone please confirm that this is still OK to do?

Thanks,
Chris

OK, I'm clearly missing some knowledge here. I measured the resistance between the GND of both PSUs (when the AC-DC PSU feeding them both was off). The result was tens of Mohm (this seems to go down the longer I measure).

When I switch on the PSUs and then measure the voltage between the 2 GNDs I get 0.00V. When I set one PSU to 5V output and then take my meter and hold the positive probe to the output of that PSU but the negative probe to the GND of the *other* PSU I measure exactly 5V.

It's as if the GNDs become "connected" only when the PSUs are on.

 

Chris

[BlackFX]

60v seems like more than just a little to me.

I have attached a pic of the damage it did to the clip on my scope lead (scope is okay thankfully)

[AlexFerro]

I was thinking little, as in just enough current that you'd see it on the volt meter, but not enough to actually register if something was connected. Just like how it'd pretty easy to measure a volt or two AC on unconnected leads. After seeing the second picture, I'd agree about that being an issue. As to why it's 60V, that's suspiciously close to the input voltage it measures on the psu as shown in your screenshot. I definitely should check mine, and see what it's doing next time I'm can.

[BlackFX]

I'm wondering if a crappy SMPS is to blame, I have taken a couple of photos of what I'm using.

[BlackFX]

And the back

[AlexFerro]

You could always make the same measurement between each of the output terminals of the AC PSU and real ground when you have it wired up the same way as in the chassis. My gut feeling is that won't show anything unusual but my gut feeling was that your earlier post was a non-issue, so take that with a grain of salt.
Does the 60V go away when you switch the output on the rd6006 on?