help with a APC ups mod

[yonu]

Re: help with a APC ups mod

Ok here is the label on the transformer

[budm]

Re: help with a APC ups mod

It is still charging the batteries and still talking to the computer?

[yonu]

Re: help with a APC ups mod

it is still talking to computer but not charging so I will patch that trace tomorrow and see what it does not even sure when it burnt as it was charging

yonu

[budm]

Re: help with a APC ups mod

I think that is part of the charging circuits.

[kc8adu]

Re: help with a APC ups mod

the older ones yes.
these newer,cheaper ones get hot even without load.
some are wired up as autoformers so be careful.no isolation!

IDK, you can get some decent current out of them.

[yonu]

Re: help with a APC ups mod

Ok I patched the trace but still no charging still talks to the computer though lol

[yonu]

Re: help with a APC ups mod

ok question I have a couple of old metal back-ups 400 that are fully working would I be better off attempting to mod one of them forgot I had them.

Thanks,
Yonu

[budm]

Re: help with a APC ups mod

Is that the exact model 400?, I can see if we can get the diagram for it.

[yonu]

Re: help with a APC ups mod

according tot he label on it yeah here is a pic of the label

Thanks,
Yonu

[budm]

Re: help with a APC ups mod

But it does not look like it has any interface for it to talk to the computer.

[yonu]

Re: help with a APC ups mod

it has a db9 I haven't hooked it up to see what data it will pass

Thanks,
yonu

[kc8adu]

Re: help with a APC ups mod

cable has non standard pinout(thanks apc!)
iirc there is still a site ups club that has pinout and schematics of these older units.
supported under windows and linux natively.
these i add a fan to that only runs in inverter mode.
so now you have a charger,monitor,and a working ups limited only by the battery you connect.

[yonu]

Re: help with a APC ups mod

first on the 350 I found the problem with the charging circuit apparently the TL780-15 blew out as it is only outputting 1.5volts.

now on the backups 400 do you happen to know what the charger can output as I have no interest in the inverter portion of the unit only the 12vdc side but I had to plow the charging circuit the first time I hook it up as I will be pulling roughly 3amps eventually 5amps,

Thanks,
Yonu

[budm]

Re: help with a APC ups mod

If it uses one 12V battery then more likely to be the same setup as the 350, around 1~1.5A for charging circuit, you can look for the voltage regulator on the board around the transformer.

[yonu]

Re: help with a APC ups mod

Ok I have been going over the PCB and I have no idea on the regulator as they are all heatskinked and you can't read the labels

yonu

[yonu]

Re: help with a APC ups mod

ok would it be possible to use something along the lines of what you posted earlier that but to use a relay to use an external charger instead of the built-in charger or would this cause the ups to be unable to detect the battery? the reason for this being I don't want to kill the builtin charger pulling to much current or my deep cycles by not charging them with enough current.

Thanks,
Yonu

This is one of the simple way to do it.

[budm]

Re: help with a APC ups mod

The UPS batteries monitoring circuit that talks to the computer is connected to the terminals of the batteries, so if you connected the external charger to it, you will have to make sure that the external charger will not force feed the Voltage/current into the internal charger and cause damages. What does it show on the PC right now on the 350 when the power switch on the UPS is not on and the batteries is not connected?

[yonu]

Re: help with a APC ups mod

nothing it will not even turn on without a connected battery I am assuming it has something todo with the blown TL780-15

yonu

[budm]

Re: help with a APC ups mod

It should communicate with the computer even when the power switch is off (if that is the way APC works, I am not sure), the charger is also always on regardless of the power switch is on or off. The blown 780-15 may also used for running the monitoring circuit beside running the charger.
The monitoring works the same way as what you are trying to do, when the power is present it runs off the power supply and when AC is not present it runs off the batteries so it can keep the communication going with the PC.

[kc8adu]

Re: help with a APC ups mod

all apc i know of must have a battery to do anything.