45A power supply for £14......

martinedwards

looking on ebay for a power supply.....

flippin' blimey heck they're expensive!!

I don't like spending money where I don't need to, so rather than drop over £100 on a power pack...........

I've used several ATX supplies for radio use, but my latest aquisition of a Yaesu FT747GX needs over 20A. more than the 15A available from the ATX.

someone on the Hamradiodeals forum suggested a server supply, so a little googleing for info, and a glance at ebay got me a HP DSP-600PB for £14 delivered.......



there is no NEED to take the top off other than to remove the locking bar with the red knob shown at the top of this pic.

I used Futaba RC plugs to access the 12 pins. I COULD have soldered direct, but this was going to be awful fiddly, and I had a box of random Futaba bits......

so far I only want 4 of the 12 pins.

numbering them like this.....

1...2...3
4...5...6
7...8...9
10.11.12


4 & 8 together lower the fan speed.

6 & 10 together, and connected to the other two switch the whole thing on.

you COULD put a switch on there if you wanted with 4 & 8 on one switch lug and 6 & 10 on the other.

I don't want one, so I just twisted those 4 wires together and soldered them.



there are other things you can use the other pins for, so I'll keep those available, just not used now.

connecting to the spades is a little akward so I made some pins by stripping back some insulation then tinning it to make it rigid so I could push it in between the spades and then soldering it in place.




repeat for the other wire, plug it in and she's a go!

1st QSO was with OE1LZA, Laila, who gave me an all clear on audio. 6 more QSOs around Europe mean all is fine and dandy.

technical knowledge needed?

pretty much nil.

a 47A 12v supply good for radio use or charging batteries..... for £14.....

can't be bad for that!!

thanks due to:

http://www.ultimaterc.com/forums/showthread.php?t=174225

and

https://sites.google.com/site/tjinguytech/my-projects/HP47A

for the info I used to make this happen.

martinsvi

legit HP PSUs cost a LOT more that 14 gbp unless they're second hand low spec units. Also it should make a lot of noise from the cooling fan. Be very careful with this thing!

watty

Doesn't 12V vs 14V (car battery fully charged is 14.2, the 13.8 V is older tech batteries, or battery not charging) limit power to 80% of max?

Some people use a car or truck battery and a smart charger. Then they are sorted for power cuts too.

martinedwards

the fan isn't too noisy, I have it under the table and I always use headphones anyway.

the 12v can be tweeked by putting a variable resistor across two of the other terminals.

a little more reading and I need a more accurate multimeter before I attack that.

Capt'n Midnight

You could get three ATX computer power supplies and wire the 5V in series to get 15V - check your equipment to make sure it's rated for 16V !!! (or 2x5V + 3.3V for 13.3V )

It's messy to do since the power supplies usually have the chassis at 0V so you'd need to isolate them from each other or you'd short them out. Easiest way is to get a strip socket and put plugs in backwards so earth pin isn't connected. Also the whole fun and games about live and neutral being out of phase. YMMV

martinedwards

you ever tried that?

I've looked at the idea of Paraleling the ATXs and got "NO! DON'T EVER TRY THAT" but I guess the series should work.....

still, the server supply works nicely for much less than 3 ATXs