Dps600pb Voltmeter Connection.

[CmdrBond]

Greetings, first post so go gentle

I'm here because of the write up on the DPS600PB here: 1000w Power Supply Using 2 Dps-600pb, Affordable, Dependable, Powerful!!

Rather than necro an old thread, I thought it best to start my own.

I'm in the process of obtaining the parts to create my own parallel DPS600PB supply (this is actually for supplying power while programming BMW/Mini cars.

I know how to wire it all together, and have no issues with that, but I did have a query that doesn't seem to be answered anywhere - or even discussed...

I'm going to connect a rheostat/potentiometer between pins 7 and 9 to control the output voltage and bring it up over 13v. I'm going to be aiming for 13.6vdv, but realise this is close to the OVP cut-off.

My question is with regards to measuring the output voltage.

I will be wiring in an LCD voltmeter display. Now while I could hard wire it to the 12v output terminal, I'd rather not. I plan on connecting to these terminals with 12-10awg spade terminals.

With that in mind, and being told that pins 7 and 9 are tied to the 12v rail, does anyone know if the output on pin 7 would match that of the +12v connection?

If yes, would wiring a voltmeter between pin 7 and 8 (GND) affect the operation of the rheostat connected between pins 7 and 9 ???

 

[Smoggie]

i did a similar power supply conversion with 2 x 600PB supplies years ago, i still have the powersupply today, it works very well.
What i did find though is that when you try to trim the output voltage much above default, the power supplies become unstable when running at high output current and trip out. In the end I removed the voltage trimmer pot and let the supplies run at default. Based on my experience i'd recommend not to bother trying to play with the output voltage.

 

[CmdrBond]

i did a similar power supply conversion with 2 x 600PB supplies years ago, i still have the powersupply today, it works very well.
What i did find though is that when you try to trim the output voltage much above default, the power supplies become unstable when running at high output current and trip out. In the end I removed the voltage trimmer pot and let the supplies run at default. Based on my experience i'd recommend not to bother trying to play with the output voltage.

Interesting.

However, I need a minimum of 13v. Current load will generally be around 25-30A, but could potentially get to 70A!

But people are using these for this exact purpose.

Things I have noted, some guides recommend placing the resistor between pins 3 and 9 - which can result in strange behaviour as you're injecting a regulated 5v source rather than the +sense which "should" be more accurate.

Additionally, cabling... Short fat cables give a better result than long thin cables.

I was going to connect the 10awg output wires together into a single 4awg cable, but instead I'm going to take all 4 wires to the terminal, but keep them short (under 18") this loses 1 connection point, and the CSA is marginally greater all the way to the terminals.

 

[Smoggie]

I'm guessing then that you plan to use two supplies in parallel rather than in series? My power supply was used for a battery charger which needed 24V+ so I did the series connection.

It was years ago, but I'm pretty sure that i couldn't get 13V to run stable when the supply was at high current output. I was running them very close to their 48A (each) output though. If you don't push them that hard they might be ok at 13V

 

[CmdrBond]

I'm guessing then that you plan to use two supplies in parallel rather than in series? My power supply was used for a battery charger which needed 24V+ so I did the series connection.

It was years ago, but I'm pretty sure that i couldn't get 13V to run stable when the supply was at high current output. I was running them very close to their 48A (each) output though. If you don't push them that hard they might be ok at 13V

Yes, a parallel set setup.

Just a query? Are you on 110 or 220v for your home supply.

I'm in the UK, and that should give me 55A output, but 110vAC would only give 47A output, so 48A would definitely cause issues.

 

[Smoggie]

UK, 240V

240v x 15A = 3600W so your wall sockets aren't going to be any limit. The DPS600PB is rated at 575W so even two is not getting anywhere near the wall socket rating, even on 110V

PS.. yes the limit of the PSU is 47A, not 48A.. my memory was playing tricks.

 

[CmdrBond]

Ok, in all my research, I was confusing separate units.

There's 1 that had a different output depending on input voltage, but it's not this one

Input is 8.6A max

Output is 12.15v @ 47A max and 5vsb @7A mac