Power Supplies

[gordonbw]

What are people using to power their chargers these days?  Many years ago I converted an old AT computer power supply, and it served me well for a long time.  Now, with higher voltage and capacity batteries, it no longer does the job, so I need an upgrade.  Are you guys using the newer ATX power supplies, server power supplies, or dedicated bench supplies... And where are you buying them?

[Andy Hoffer]

What are people using to power their chargers these days?  Many years ago I converted an old AT computer power supply, and it served me well for a long time.  Now, with higher voltage and capacity batteries, it no longer does the job, so I need an upgrade.  Are you guys using the newer ATX power supplies, server power supplies, or dedicated bench supplies... And where are you buying them?

I have always been a big fan of ATX power supplies.  They have always filled the bill for me.  I get mine from old PC's at curb side or from the Gorilla Store (Active Surplus) on Queen Street West.  They come in all sizes and are very reasonably priced.  Not sure if they carry server power supplies, but I would not be surprised.

Andy

[gordonbw]

Andy, how much power are you asking your ATX supply to deliver?  My old AT supply seems to have a top end of 3.5 amps, above which it will not operate the charger.

[Andy Hoffer]

Andy, how much power are you asking your ATX supply to deliver?  My old AT supply seems to have a top end of 3.5 amps, above which it will not operate the charger.

Hi Gordon:

I have one ATX supply that provides 4.2 amps @ 12 volts, another that provides 16.0 amps at 12 volts.

Andy

[sihinch]

I have a 200 watt HobbyKing power supply and a 350 watt Progressive RC power supply.

[Bobmic]

Unless you charge at low currents 12v ~15Amp power supplies will not be enough - you are looking at under 180W.
Most of the chargers today are between 200-400w.
It all depends on the batteries and chargers you are planning to use.
If you have a larger PS you can always use multiple chargers. I am using 350w PS from hobby partz which was relatively cheap and is working well. Most of the newer PC power supplies will be good and server ones will be even better.

[Andy Hoffer]

Anyone know if you can safely wire two smaller 12 volt power supplies in parallel for greater current capacity to power larger chargers?  Any technical issues with doing so?

Andy

[Ededge2002]

I have a mean well 320W one that I no longer use. Its a solid unit but is 17.5-27Volts. Some of the newer chargers are 18 volts in. Please check your application.

$40

http://ca.mouser.com/Search/m_ProductDetail.aspx?Mean-Well/S-320-24/&qs=moO/8p2KOt%252b2QRvG/65Ryg==

[gordonbw]

Ed -- thanks, but all my current chargers are 12v.

[Tom]

I just ordered this power supply from eBay...
http://www.ebay.com/itm/12V-29A-350W-AC-DC-Universal-Regulated-Switching-Power-Supply-/350589142705?ssPageName=ADME:L:OC:CA:3160

$28 including shipping.
I'll let you know how it works out.

[Tom]

Anyone know if you can safely wire two smaller 12 volt power supplies in parallel for greater current capacity to power larger chargers?  Any technical issues with doing so?

Andy

Power supplies typically don't like to be paralleled - unless they were specifically designed to do so.  I don't believe ATX power supplies will work in parallel.

[Andy Hoffer]

Thanks Tom.  Much appreciated.

Andy

Anyone know if you can safely wire two smaller 12 volt power supplies in parallel for greater current capacity to power larger chargers?  Any technical issues with doing so?

Andy

Power supplies typically don't like to be paralleled - unless they were specifically designed to do so.  I don't believe ATX power supplies will work in parallel.

[bfeist]

Hi Andy,
I modded some high current server power supplies a couple of years ago. Each one is different. I suggest you don't series or parallel any of them together unless you can find someone else who has done so on rcgroups.

The PSU I converted is capable of 980W with 120V AC input, and 1300W with 240V input. It was $30 or so from a surplus place. Takes some tinkering though. You can see it here http://temac.ca/smf/index.php/topic,3514.msg16721.html

Ben

Thanks Tom.  Much appreciated.

Andy

Anyone know if you can safely wire two smaller 12 volt power supplies in parallel for greater current capacity to power larger chargers?  Any technical issues with doing so?

Andy

Power supplies typically don't like to be paralleled - unless they were specifically designed to do so.  I don't believe ATX power supplies will work in parallel.

[Andy Hoffer]

Thanks so much Ben. Looks like a good investment.  And to boot, I now understand the correlation between your days at the field and the load dispatch patterns at the Pickering Nuclear genearting station.

Keep up the good work!

Andy

[gordonbw]

So I read Ben's post -- looks like a great solution but a little more complex than I want to undertake. I have acquired a 350W, 29A Mean Well PS that looks like the attached. I want to set it up in a safe enclosure with a power switch and proper connection points so that I can use it with any of my chargers. 

As my electrical engineering knowledge is tenuous, I wanted to seek feedback on my plan.  Here's what I'm thinking:

- Mount the PS in an appropriately sized project box from Sayal, adding ventilation holes
- Mount a power switch, 120v bucket receptacle, LED and banana receptacles on the outside of the project box
- Connect the external components to the PS using 12 ga. wire.

Does this sound like the right approach?

Also, the PS has three pairs of -ve and +ve 12V connection points.  Should I gang these together, activate only one, or have a separate input for each of the pairs?