I have LM317 regulator and LM339N in my UPS charging circuitry. Will I be able to use that charger for using the UPS with a car battery?. Instead of by passing.

I think I found the problem with the UPS. It is nothing else, but a dead battery. I borrowed my brothers motor cycle battery for testing after I had nothing to check further on the Mainboard. After connecting that battery. UPS came online with green indicator up. disconnecting A/C switches the UPS t...

Yes, that seems to be full wave rectification with two diodes. Thanks. http://img3.imageshack.us/img3/391/rect.gif I checked the both diodes with 1 pin desoldered. And the both diodes are ok. Checked with multimeter. Replace the both LM339N and the LM324N. Replaced an unsure relay driver transistor....

I have been reversing the PCB of the UPS to get some schematics. And I came up something like this, http://img839.imageshack.us/img839/3841/83815989.gif http://img202.imageshack.us/img202/7065/poweri.jpg The resistors are same valued. The two LM339N s and the LM324 are powered using this power conve...

Well, First wishing Nipuna good luck with the exam. :) And I checked the circuit further. And I am checking the details of the components in the circuit. Battery charging unit is working. And the transformer is also in good condition. Stepdown is working.( i read about 16 volts AC, when the 220V pri...

There is an amber LED on my UPS. And the manual says that it should be turned on while charging the battery. But it never came up since the first day I started using this UPS. I am wondering if the charging circuit is malfunctioning. And I took the UPS apart. Just going through the components to fin...

Looking forward to hear. I have the same UPS model with the same problem. I am going to have a check on it today. It was lying around for about 5 months. I can't ask for money from my parents for a new one. I am still studying. No job

Computer Component market in Sri Lanka has to be regulated.
There are so many people selling shit at Unity Plaza.
And A&G Graphics, STLabs... what are they. I have not even heard of those brands. And can't forget the low quality Chinese shit too.