I have two transformers (430-7105) removed from APC ups units. Each of them has 14v output at about 40amps. No center tapping. So i could use two transformers connected together for 14-0-14. My amp is 6 ch of (10watts) chip amps.
I have seen many times ppl use nice toroidal transformers with amp projects. What are the downside of using those huge UPS transformers (in therms of performance, quality and etc..)
Any comment will be appreciated.
I have seen many times ppl use nice toroidal transformers with amp projects. What are the downside of using those huge UPS transformers (in therms of performance, quality and etc..)
Any comment will be appreciated.
not much apart from them being heavy. They use good quality insulation and nice thick copper, so they have very good regulation and low copper losses. They are rated for continuous full load, so both primary and secondary sides are wound with nice thick wire.
The only disadvantage is that if you dont mount them solidly they can buzz.
They can also supply a LOT of current very quickly so a soft start is a good idea because they can easily blow bridge recitifiers. 40 amps continous and they can easily provide 10 times that peak.
The only disadvantage is that if you dont mount them solidly they can buzz.
They can also supply a LOT of current very quickly so a soft start is a good idea because they can easily blow bridge recitifiers. 40 amps continous and they can easily provide 10 times that peak.
Damn thats a dangerous design! Every UPS transformer i have seen is fully isolated, by law i think in australia as the smaller plastic cased UPSes are double insulated, and have user replacable batteries.
The bigger UPS's these days all use high frequency inverters which have no real useful components apart from some nice relays/caps and perhaps mosfets and inductors.
The bigger UPS's these days all use high frequency inverters which have no real useful components apart from some nice relays/caps and perhaps mosfets and inductors.
Thanks all. Its isolated. I checked it. Unfortunately it takes about 18 watts with no load. Pretty high waste of energy.
that means that you have a high capacity traffo, what is its wight in kgs? or lbs?
siince most ups are mostly intended for intermittent duty cycle, that is not so surprising....
building my own traffos, i can say that design considerations for a regular line operated traffos can be different with that for a UPS...
how do you know? i did not see the OP post an actual model number so we can check...
you mean on-line? i have worked on such installations working for Oil and Gas refinery Projects,
a battery bank in its own room with about 120pcs of 2volt storage cells wired in series,
a transfer switch on another room with the sine wave inverter and distribution boards...
capacity at about 50kva with autonomy time of 12 hours.....
yes i have seen those..
you mean on-line? i have worked on such installations working for Oil and Gas refinery Projects,
a battery bank in its own room with about 120pcs of 2volt storage cells wired in series,
a transfer switch on another room with the sine wave inverter and distribution boards...
capacity at about 50kva with autonomy time of 12 hours.....
yes i have seen those..
Thanks all. Its isolated. I checked it. Unfortunately it takes about 18 watts with no load. Pretty high waste of energy.
did you use a kill-a-watt type device to measure power?
How are you measuring that wattage?
its inductive, so its mostly apparent VA, not real VA.
Measured from a KillaWatt. Measure some other toroidals and gave zero watts on them.
I'm guessing this xfmr is probably for the inverter. It is used as a stepup xfmr. The inverter likely uses a 12 volt battery and a pwm controller driving a center tapped bridge. It may not be to happy with operating as a 60hz step down xfmr. If it gets even warm with no load it's probably saturating the core.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
- Home
- Amplifiers
- Power Supplies
- UPS transformers for Audio amp?