2 power supplies

[Mr_Gnome]

I have two Pyramid 52 amp power supplies. One is new and the other one I need to replace the eight transiters on the heat sinks and the voltage adjust pot on the front.

I run an RCI 6900F25 and a Cobra XL450 amp. On AM I can run the amp on max, but on SSB I can only run it on high because there isn't enough amps for max.

Once I get the old supply fixed how would I go about hooking them up together? Is this taking a big chance of blowing something, etc?

Thanks,
Mr Gnome

 

[me 99]

Once I get the old supply fixed how would I go about hooking them up together? Is this taking a big chance of blowing something, etc?

Use a heavy gauge cable (2 guage or bigger) and connect + to + and - to -.. People have been running them like that for years with no problem.. You would be best to get yourself a volt meter and set each one to the same voltage before you hook them up..

 

[KingCobra_CDX882]

also
by hooking both 52 amp power supplies together
you will get 78 amp supply (as though it was a single supply)

 

[bob85]

i would also use a high amperage diode in series with each positive line from the supplies to isolate them from each other,
you will get volt drop across the diodes so turn the supplies up to compensate,
the diodes will stop any smoking supplies if you accidentally turn one on before the other or in the case of one supply developing a pass transistor short,
turning the voltage up wont stress them it will give the pass transistors a slightly easier life,
you must ensure both psu's are set exactly the same, the slightest difference will cause one to work MUCH harder than the other ..

 

[Mr_Gnome]

On each power supply they have two (+) and two (-) for hooking up more than one thing. One time I followed someone's advice (on the forms here that owns his own radio shop) saying it would be better to hook up both the (+) together and both the (-) together. It was not a good idea! It cooked the pills in the amp and finals in the radio...maybe even more, I don't recall. So to say the least, I'm leery about going there again!!!

On using high amperage diodes, how do I go about that? Put one diode at the end of each wire?

How high of a high amperage diode would I use?

From that point what do I do? Run them to like a project box with thermals to hook the radio/amp to?

Are both sets of terminals needed from each power supply, or just one set from each for the amp? Then run the radio off of one of the other sets of terminals on either supply?

Thanks,
Mr Gnome

 

[bob85]

use equal length reds and equal length blacks,

take one black- and one red+ from each supply,

cut the reds and insert one high amperage diode with banded end away from supply in each red lead,

twist and solder the two reds together on banded end of diodes,

twist and solder the two blacks together as usual,

use a suitable high amperage connector block to hook your gear to the twinned up reds and twinned up blacks,

make sure they are set to EXACTLY the same voltage before you hook them together,

leave both supplies turned on and switch them on and off at the wall socket or other convenient place,

i would use diodes at the very least 2x the peak current rating of one supply the bigger the better preferably bolted to a suitable heatsink,

feel the temperature of the diodes under full load make sure they are equally warm and up to the job,

the hardest part with psu's that dont have current metering is ensuring both units are delivering equal current under load,

cb power supplies are marginally rated at best and do not like running at full output rating for extended periods of time,

i have done it with and without diodes and they both worked ok but the first time i accidentally switched only one psu on without diodes i smoked the other supply,

you should not have any problems doing that with 2 of the same units set at the same voltage but i cannot guarantee you wont,

I AM JUST TELLING YOU WHAT I HAVE DONE IN THE PAST THAT WORKED FOR ME :!:

the best idea would be sell them both and buy a psu that will do what you want,

 

[Mr_Gnome]

bob85,

So I only need to connect one set of the (+) and (-) from each power supply?

Can I just run the radio off of one of the extra sets of terminals on one of the power supplies...or should I make an extra set of terminals on the amperage connector block and run EVERYTHING from there? Thinking about it, probably from the block, huh?

Keeping both supplies at the same volts might be a problem making sure neither one of the voltage adjustment knobs gets bumped.

I used to run the radio off it's own supply, and if I remember right, doing so gave the amp enough amps to run on SSB set on the max setting. If this is the case, then after I fix the supply I won't have to worry about it anyway.

Thanks,
Mr Gnome