Need to rent a power supply

[bjbdts]

Hi, everyone:
I need to rent a power supply. Output Voltage=24-26V, current abuot 60A. Any recommendation is appreciated.

thanks
bj

 

[RalphChristie]

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[bjbdts]

Hi, RalphChristie:
I am in southern california, close to Los Angeles.
bj

 

[OperaHouse]

Go to eBay, you can generally buy one for less than the price to rent one for 2 weeks.

 

[itsmoked]

THAT! is a non-trivial supply... Arc welder on low..

That's a 2kW supply.

You are looking for an HP or Agilent 6573A.

It will cost over a grand.. used

There are a couple big rental agencies that will come out in the paid stuff on a google search.

It will be quite rare to come by.. (Bend over grab ankles)

It will not be a matter of which company do I choose but rather who (if anyone) has one.

 

[ScottyUK]

Cheap option might be a battery charger for a truck? What regulation do you need?

For rental units I've used the Farnell / Advance AP1000 and AP3000 series supplies, also one from Power Ten a while ago whose model number escapes me. These are all really big laboratory supplies - expensive to rent, but sometimes you need one quickly for a one-off job.

Astec Standard have a good range of heavy current power supplies. Their VS and MVP series are good for 2.5kW and 1.0kW respectively, depending on the output voltage and current configuration. You might find buying a component PS is comparable to rental of a large bench instrument.



----------------------------------

One day my ship will come in.
But with my luck, I'll be at the airport!

 

[fsmyth]

I got some, but I am in Texas. Lemme know if you
still need one. Some are analog, and therefore heavy.
Some will need 208/220v 3-phase power. Is it available?
<als>

 

[OperaHouse]

You can be creative. Use 6V golf cart batteries! Need it adjustable? Add in series a 60A 7-10V power supply in series with three batteries. These are cheap because no one needs them anymore. Connect a resistor in series with the sense input to the highest battery. After it is over, give the batteries to your boss for his golf cart. WIN-WIN

 

[Higgler]

sounds like two 12 volt car batteries would work, cost $150 total. 2x12=24v. Put them in a box for safety, in case you short circuit them.

I think most batteries are 90 amp-hours.
kch

 

[itsmoked]

OperaHouse.... That IS creative!

 

[bjbdts]

I'am thinking about putting the things I have together to meet the requirement.
1. one DC-Dc converter: 48V input, gives me 26V, 40A output.
2. two BK precision 1692 each can provide 13V, 40A output.
So is it safe if I connect two BKs in series and then parallel to the converter to provide 26V, 80A?

Thanks,
bj

 

[itsmoked]

Oh.. That could be very tricky.. Series-ing supplies with a current requirement lower than the "weakest" no problem. Paralleling? That is far more problematic.

The source with the lowest internal resistance will try to hog the load and trip, fail, release smoke, etc.

You can relieve this problem somewhat by driving your load from your two sources thru individual resistors that essentially swamp the internal resistance aspect and allows your supply's a spongy connection to the load.

 

[itsmoked]

bjbdts; What are you trying to drive? Makes a difference.

 

[bjbdts]

I am trying to drive a RF amplifier to full power: 180W.

 

[itsmoked]

Good grief! Talk about inefficient! [180/2000]x100 = 9%

But that's beside the point.

Depending on your transmission form, and I'm no ham, maybe you could use just one of your 40A sources and a large capacitor. Or as operahouse suggested batteries. Use two 12V batteries in series 13.7V x 2 = 27V.

Set up one supply to charge the batteries to the rated voltage then run your amp from them while they are charging. Essentially using them as extremely high capacity caps.

If your transmission is sideband or some other on off style then the batteries can be replenished during the no transmission moments.

 

[Higgler]

RF amps can put out extranous signals due to ripple in the voltage you power it up with. Switching supplies use many 10's of khz switch rates, and I've had testing requirements to look at the switch frequency spur levels on a Spectrum Analyzer.
If you have any spur testing or signal purity requirements, then batteries can help eliminate problems.
If your requirements are pulsed RF power, at 180 watts, that can cause some droop in power supply outputs.

kch

 

[VEBill]

The boyz in the bling-bling Hondas with the 800 watt subwoofers have created a market for components that might help with providing high current, filtered power. There are high current fuses, huge capacitors (mind the voltage), cheap and cheerful large gauge wire and connectors.

I've got a Lambda 15Vdc 80A PS at home (adjusted to 13.8v, flea market find, Cdn$40 ) and it isn't all that large (rack mount, perhaps 5-inches tall). I assume that Lambda has some combination of off-the-shelf products that would work.

Link:

http://www.lambdapower.com/index.htm

A normal 15A AC outlet won't cut it for this much power (more than 1.5kw output).

 

[bjbdts]

$40 is reeeeally cheap. There is one ps from lambdapower on ebay now costs over $600.

bj

 

[VEBill]

There seems to be many price-oblivious buyers on eBay - I'm not sure why.

Must...clean...out...basement...and...retire...early.

I only circled that PS once before I grabbed it.

 

[OperaHouse]

There is a HP 6260B 10V 100A in its last hours with no bids that has problems, but is only $20 (75 shipping). Shipping is always a problem with these. I have a nice adjustable 5V 150A lab supply that I've always been thinking about rewiring to 12V. Just anothe dust collector. Got to thinking about hooking that up with my 15V 300A 3 phase adjustable unregulated. Another dust collector. Never use it, but ate to throw it away. Lots of this stuff out there.