I'm not sure how much good this would do since it runs off 24V(2 12V batteries in series). Would there be any uses for that?Before you canibalize it for parts, have you tested hooking good batteries to it ?
That is mostly what fails in UPSs. And you would be disabling what many people is after, a huge DC to AC inverter. I use one in my car for 115VAC on board.
I will get you one tonight. ThanksThey are likely the main power transformers that step up the lower voltage up to the higher line voltage. They will have the primary's as the low voltage and the secondaries as the high voltage. But typically you can reverse them if needed to make a linear power supply out of them. and being UPS transformers they will have a high surge capacity.
However most UPS units have smaller transformers than they are rated for output wise. Their duty cycle is limited by the battery capacity so they dont need to be continuously rated at their maximum capacity. Many can only hold their maximum rated outputs for a few minutes and typically can only do about half there maximum rating as continuous duty units.
Also if used as step down transformers their outputs will be much lower than what the DC drive voltage was. Being a 24 V system they will likely only have about half that as an AC output. To maintain the steady line voltage as a backup power supply the use a sort of PWM method to keep the line voltage constant even though the battery voltages drop off rather fast.
Their windings ratios typically are closer to being what the battery's lowest working voltage is and then having that stepped up to the peak voltage of the output wave form. Hence the lower output voltage when used as a step down transformer.
Got a picture available. It would help with explaining what you have.
I'm sorry, so what are they? Step-down or Step-up?This is an old version of UPS. The two transformers are 60 Hz (or 50 Hz if Europe) which are good to salvage. You may find some rectifier diodes used for charging mode. There will be some power transistors, likely MOSFET's used for and H-bridge for generating the modified sinewave. The rest of the electronics if for sensing of A.C. and charging control. You may find a 24v DC power relay for making the AC crossover from mains to UPS output.
New version UPS's use high frequency switching circuitry for DC boost. They are much lighter weight as they use small high frequency ferrite transformers.
I should be able to use them as linear transformers though? Connect them right to mains?They are used in a step up application here. But technically transformers are bidirectional. If you apply line voltage to what was the output it them becomes a step down transformer.
Most likely they have the leads attached to the heat sinks because of the type of switching system they use. Its normal in many UPS designs.