View Full Version : i need more power LOL

12-04-2010, 01:12 PM
Hi guys dont know if this is the correct section to post this??

As the tittle says i need more power
well i am looking to get around 80v to run a servo cant find any cheap supplys in my budget being totaly skint lol

but i was wondering if any one has run the PS407 (40vdc ) power supplys in series
as i have four of them and that would be a bonus if it were posable

i know alot of power supplys can be run in series just wondered if any one has done it ???

cheers for any help !!

12-04-2010, 02:05 PM
Any powersupply can be run in series. You just need to take some simple precautions

First the obligatory WARNING: do not attempt if you are at all unsure. Following this advice is at your own risk. 80v is deemed a dangerous voltage and should not be worked on without assistance [its one reason why phone systems are 50v - so they can be worked on by a single engineer]

The key to stacking supplies is to ensure that the output of the supply is totally isolated and floating with regard to the chassis ground and mains earth. The lowest supply in the stack may have (arguably should have) its -ve rail connected to chassis ground.

Take the supply you wish to use as the upper one in the stack and make sure it is isolated from the mains supply and that the output capacitors are discharged by putting a low value resistor across them. Now measure the resistance from the each output rail to the casing and to the mains E terminal. if that is open circuit (at least >1Mohm) then it is ok to use. If not then you need to dismantle the supply to find where the connections are and isolate them. This is usually through hold downs for PCBs.

Once isolated it is simple them to attach the +ve output of the lower supply to the -ve output of the upper supply in the stack. The final output voltage is between the -ve of the lower and the +ve of the upper.

Be careful - safety first. High current DC supplies are more dangerous than AC!

12-04-2010, 02:41 PM
Well i just contacted the supplyer and he seemed sure it would be ok
so i went a head and done it seems to work ok fingers crossed

( i take no responsability for anyone seeing this post and doing the same do at your own risk!!! )