[kenshie]

ok so im using this generic 500w omega psu (model number: 500atx) to power a small audio system in my room. It consists of a 400w Almani amplifier (al-ch-400), a 2 farad Power Acoustik capacitor, a power acoustik preamp (pwm-20) and some speakers thrown in for fun.

problem is, only 300w from the power supply goes to the two +12v rails and the other 200w is locked into the +5v and +3v rails.

is there any way i can free up the other 200w to get the full 500w on the 12v line? would removing the 3v and 5v transformers help?

(couldnt find link for the psu)

 

[TwoCables]

Don't use this PSU. It may fail and kill your equipment - especially if the draw gets too close to the limit (the limit may be much less than 400W).

It's just as bad of a reason to use this for that equipment as it is for a computer.

 

[kenshie]

bleh... im planning on buying a professional power supply for audio equipment but for now this has to do. thanks for the heads up though

 

[TwoCables]

Quote:

Originally Posted by kenshie bleh... im planning on buying a professional power supply for audio equipment but for now this has to do. thanks for the heads up though

I don't know: I personally wouldn't trust it at all. But don't let me stop you. I don't want to be the reason you don't get to have fun. But I also don't want to see you lose the equipment if the PSU fails (and generic PSUs are known for failing and then taking everything with them).

 

[kenshie]

everything is under fuse protection so im not too worried about it.. also the psu is relatively new (less than a year).

 

[TwoCables]

All I can say is that this is a risk. But replace it as soon as you possibly can.

 

[hermitmaster]

The amperage on the 12v rails is more important than the wattage. Make sure the output exceeds consumption. Fuse within 12" of the PSU.

 

[kenshie]

total amerage on the 12v rails is 29 (15A+14A) i need at least 44A according to my calculations... which may be wrong

 

[TwoCables]

Quote:

Originally Posted by kenshie total amerage on the 12v rails is 29 (15A+14A) i need at least 44A according to my calculations... which may be wrong

Unfortunately, adding the rails together like this is actually not how the total amperage is found. To find it, the total wattage capability of the +12V must be divided by 12 which would mean that this PSU has an absolute maximum amperage rating of 25A for that +12V output.

This is one reason why it's so important to avoid generic PSUs.

 

[this n00b again]

Quote:

Originally Posted by kenshie ok so im using this generic 500w omega psu (model number: 500atx) to power a small audio system in my room. It consists of a 400w Almani amplifier (al-ch-400), a 2 farad Power Acoustik capacitor, a power acoustik preamp (pwm-20) and some speakers thrown in for fun. problem is, only 300w from the power supply goes to the two +12v rails and the other 200w is locked into the +5v and +3v rails. is there any way i can free up the other 200w to get the full 500w on the 12v line? would removing the 3v and 5v transformers help? (couldnt find link for the psu)

Short answer NO.

In reality, yes, If you want to do some circuits and replacing components, but with the cost of buying parts, replacing/modifying transformers, and effort put into modifying the circuitry it would be more efficient to just get the right psu.

Also 2 farad cap is not the right cap to be on that system. You having a cap on that system is just drawing more power from that psu and over all puts more strain on that psu.

Quote:

Originally Posted by TwoCables Don't use this PSU. It may fail and kill your equipment - especially if the draw gets too close to the limit (the limit may be much less than 400W). It's just as bad of a reason to use this for that equipment as it is for a computer.

This

 

[kenshie]

Quote:

Originally Posted by this n00b again Short answer NO. In reality, yes, If you want to do some circuits and replacing components, but with the cost of buying parts, replacing/modifying transformers, and effort put into modifying the circuitry it would be more efficient to just get the right psu. Also 2 farad cap is not the right cap to be on that system. You having a cap on that system is just drawing more power from that psu and over all puts more strain on that psu.

ah thanks for that.. i wud just wait it out with my current config until i get a decent psu. about the cap.. should i put a lower value or just leave it out all together?

 

[DuckieHo]

I can guarentee that cross-loading will be an issue. You will NEED to place a load on the +5/+3.3v rail or your +12v rail will be dangerous.

 

[kenshie]

Quote:

Originally Posted by DuckieHo I can guarentee that cross-loading will be an issue. You will NEED to place a load on the +5/+3.3v rail or your +12v rail will be dangerous.

a resistor perhaps? what value would you recommend?
i have a 2.7ohm 5W resistor i use to charge the cap before i run it direct on the psu would that work?

 

[kenshie]

ok so those dont work... burnt my fingers

 

[kenshie]

i put a small light bulb on the 5v rail.. seems to work now im getting 11.7v as opposed to 11.5v.

can anyone recommend a good dc power supply for my rig? 1000w minimum as i plan on buying a bigger amp.

i found this: http://www.trcelectronics.com/Meanwell/se-1000-12.shtml

 

[wumpus]

the one in that link looks to me like a nice unit. 83 Amps is an awesome amount of power for just one 12v Rail!!

 

[kenshie]

yep it is a good unit as far as i can see. anyone here knows anything (bad) that the manufacturer doesnt state? im unable to find reviews

 

[DuckieHo]

Quote:

Originally Posted by kenshie yep it is a good unit as far as i can see. anyone here knows anything (bad) that the manufacturer doesnt state? im unable to find reviews

Meanwells are excellent.

I have a 400w +12v PSU similar to a Meanwell if you're interested.

 

[kenshie]

ok kool i think i wud buy it then.
thanks for the offer but 400w wont give me the headroom i need