If we have a cheap UPS which stopped to work and it s no worth to repair (serious damage to the electronics inside) we can keep a few parts before we drop it. We can keep the cables , the box, the sockets and of course the transformer. One transformer that most of the UPS use is the RT 7000 BH. The connection is:
THIN CABLES: blue black (1-3 from the left) ..230 V .We dont use the thin
Red (2) between blue- black (black-red .200 v it is used when the voltage falls a little down we dont need it.)
THIN CABLES: green - black to the right ..17.5-19 V little current.
FAT CABLES TO THE OTHER SIDE: red blue or red- black . 7.5 V big current
Black blue 15 V. big current
The same colours are in most of the UPS transformers (other type).
If we want to be more sure we connect an AC 12-15 V transformer to the two fat cables (not this fat in the middle-here the red one) and with a multimeter we check to find where we get voltage 230 V. We connect here the 230 v voltage (we disconnect the 12 V transformer first) and measure all the other prices.
With a rectifier bridge , a capacitor and a part to stabilized the voltage (lm 7805,lm 7806 or lm 7812 and other types of voltage stabilizers ) we can charge 6 or 12 V batteries or gadgets that they are charged from USB connectors (5 V) etc. Generally these transformers are very useful in every lab.
YOU CAN WATCH THE VIDEO TO UNDERSTAND ALL THESE BETTER. AND BE VERY CAREFULL.THE ELECTRIC CURRENT HAS NOT FRIENDS OR ENNEMIES.