Budget friendly adjustable bench Power supplies perfect for testing LED's and other uses!

Well, there may be wiiise reasons for those supplies to come preset at “220V”.

Wonder what could happen with some folks on high voltage mains if those were preset at 110V by default…

Cheers ^:)

Yes, I have put both of mine on my scope, now my scope is a cheap unit that only reads up to 2mhz IIRC but it showed zero ripple down the finest resolution it offered.

Hey TA, you mentioned using these for charging. Do they have a charge curve for Lithium cells or do you manually adjust the charge or?

Any CC/CV supply will do, though the ones equipped with adjustable divider of end voltage current flow/end of charge indicator may be preferred:

  1. Adjust the current output (CC) to the desired value: charging speed.
  2. Adjust the output voltage (CV) to the desired value: end-of-charge cell voltage.
  3. If available, adjust the % of end voltage current flow.

Example “charging” CC/CV circuit: 1PCS LM2596 DC-DC Step-down Adjustable CC/CV Power Supply Module LED driver

Cheers ^:)

Man… Thanks! I don’t know why I didn’t know this. I always assumed the charger needed a charge curve to match lithium chemistry. So when set to cc will it charge at the set current til the end voltage is reached?


Exactly. Once the end voltage is reached, current flow starts diminishing, describing a sort of reverse exponential curve.

If present, the end-of-charge light/led lights up once the current flow goes down to the trimpot selected % value of the charging current.

Cheers ^:)

Yep, like said above, simply set the voltage to 4.2v (I like 4.18-4.19v personally), then set the current to whatever you need for that battery. Connect it to the battery in the correct polarity and let it go.

Have you got this power supply working yet? how do you turn it on? Some server power supplies are a real pain to figure out the turn on wire/signal.

If you have figured out how to get this one to turn on and working I think I might have to upgrade before long to the 5015.

The power supply works great with the DPS5015. To turn it on, just plug in the power cord.

There are only three output pins (left side in picture below). The right most pin next to the fan is negative (not grounded to case), the center pin is 48vdc positive, and the left most pin is unknown to me (2vdc positive).

There are two led indicators (labeled Fan & Power). Plug in power cord and they both light up green. I removed the cover and unplugged one fan to check voltage (it was around 8vdc) and the fan led turned to amber while the 1 of 3 fans was unplugged. Returned to green when reattached.

Hope this helps,
whopist

Thanks, thats what I was wanting to know! Now to sell my 3012 so I can upgrade lol.

Since the EPS-470 is designed for load sharing and only uses three pins to connect to the Powerservers, that left most pin should be for load sharing. Would be nice to know if EPS-470's can be connected in parallel and the left pins connected to each other would share the load equally. Two units should be enough to fully power the 5015 current wise. I did some Googling, but had no luck finding an answer.

Good question, if you find the answer be sure to let us know.

Although unless you will be using the full 15 amps at the full 50V, you can still use 15 amps from the DPS.

For LED’s 15 amps and 4.2v output would only pull around about ~1.25 amps from a 48v input power supply.

I am powering my 3012 from a 3 amp 48v power supply (set to 36v). I regularly put out 12 amps and it handles it fine but I also generally don’t use more then 60-70 watts at most, so since the power supply is a 150w power supply it handles that no problem.

I am sure you already know this, just making sure everyone else knows.

I found this post about the original DELL setup. It is called a Redundant Power Supply:

“Installing a Dell EPS-470 Power Supply
Posted by Jeff Csisar on July 29, 2014
Installing a Dell EPS-470 extended power supply into your Dell PowerConnect switch is a breeze. The EPS-470 installs through a simple power cord and connecting power cable. The power cable runs from the back of the EPS-470 into the power port in your Dell PowerConnect 3448P or 3548P.

Below are photos of the power ports on the EPS-470 and Dell PowerConnect 3548P. They show where the connecting cables install.

In addition to being able to install EPS-470 power supplies through this port on PoE switches, the Dell 3524 and 3524 (non-PoE) can have a Dell RPS-600 power supply installed. If installed properly, the LEDs on the power supply will illuminate to alert users to the fact the power supply is sharing power. The EPS-470 works by load balancing with the Dell switch’s power supply.

Pasted from <http://refurbphoneexchange.com/blogs/phone-and-tech-blog/14977029-installing-a-dell-eps-470-power-supply\> ”
Installing a Dell EPS-470 Power Supply

_
Added info:

PC3448P EPS-470 pinout
Posted by marekm
on 5 Jul 2013 20:08
It’s just 3 pins, and I have successfully identified the +/- ones, what is the third one for? I’d like to power the switch from –48V DC telecom battery backup instead of the original EPS-470, and it works but I can’t get redundant power (both AC and DC at the same time) to work properly, I can hear a relay inside click very often (which may not be good for the hardware, so I don’t leave it running in this condition for a long time). Has anyone reverse-engineered it already?
Middle pin is positive, the pin closer to the AC input is negative, and the third pin is not earth ground for sure. Left open, it’s about 2.5V above the –48V DC rail. So it may be some kind of logic input or output (or even an analog signal for some kind of load sharing?) between the switch internal PSU and the EPS-470.
I know what I ask is not officially supported, I’m prepared to void the (already expired) warranty, I’m an electronics engineer, aware of electrical safety issues etc.

Pasted from <http://en.community.dell.com/support-forums/network-switches/f/866/t/19515176\>
http://en.community.dell.com/support-forums/network-switches/f/866/t/19515176

I’m doing some network design (which includes racks and PDUs. In several cases, I need an EPS-470 power supply to provide PoE to all 48 ports on a PowerConnect switch.
I need to know, do I need one outlet for the switch and one for the EPS-470, or after the switch is hooked into the EPS-470 do I just need power hooked into that? I just need to know whether I need one or two outlets so I plan accordingly for the PDUs.


The EPS-470 adds additional power, so you need two, one for the switch and one for the EPS.

Pasted from <http://en.community.dell.com/support-forums/network-switches/f/866/t/19589890\>

Here is a 29 in 1 Connector Set I just received today. I was a little surprised to see the wire lead was 18ga.

This is to be added to my DPS5015/EPS-470 power supply project.

Set was purchased from Ebay. “29 in 1 Universal AC DC Jack Charger Connector plug Cable for Laptop Notebook” $14.

Nice posts whopist. Are you thinking the EPS-470's can be paralleled with load sharing using that third pin you mentioned?

That set looks real handy. No linky?

Great stuff.
(subbed)
J.

ImA4Wheelr,

Before I bought this Dell PS I searched for how to power it up and wire the output. Anything interesting I saved. I could follow most of it and went ahead and purchased it. It was a real gamble for me; but, the received item was perfect for my needs.

I thought a redundant power supply was a backup unit that takes over if the other fails. With this in mind I thought the third pin might be used to communicate with the system and provide status of both power supplies. Can redundant supplies combine the output?

Let me be clear about my electrical skill level. I learned everything I know from the movie GHOST BUSTERS. They said “don’t cross the beams!”. I’m pretty sure they were talking about the POS & NEG beams.

Link to Dell PS:
http://www.ebay.com/itm/142095613806

For those interested in the DELL ESP-470 Power Supply it measures 8.25”W x 12” L x 1.75” H and this is a look inside:

For those interested in the 3rd output pin, this is where it comes out of the circuit board (orange wire). Please note it appears to be labeled “IFCS”. Whatever that is? At this point I don’t plan on using it.

I’m thinking of building a power supply with DPS3012 and one 30V 10A psu .

Does the DPS3012 has short circuit protection ?

What do you mean when you say short circuit protection?

As in will it be ok if you short the leads together? Yes, it will be fine. This is how I tested the voltage drop in my leads be shorting it and leaving it that way for some time while trying different things.

If you mean protection on the input, I am not sure, I just made sure I was careful to wire it up correctly and used an XT60 connector so that I can’t plug it in wrong.