I have salvaged some used tripp-lite bcpers300 ups units and I would like to modify one of them to be just a simple 12vdc to 110vac inverter, it seems this should be possible as this ups unit uses a 12v 4ah standby battery and inverts this to 110vac when the ac power fails, so really I just need to remove the battery and install a 12volt cigarette lighter plug in its place,
remove the power cord and (heres the problem area) figure out how to make the unit think there is a ac power fail so that the inverter switches on.
I have varified the on board IC chips they are: 1-64T429 a 3-legged device,
uln2804A Darrlington array, LM339 , LM358n op-amp, PIC16C72A 8-bit cmos microcontroller, and there are other transisters, power transisters.
I have not been able to find a schematic, I quess at this point Iam thinking that maybe the microcontroller is sensing the presence of ac and the loss of ac and then activating the inverter some how, does any one out there have any advice or ideas?
remove the power cord and (heres the problem area) figure out how to make the unit think there is a ac power fail so that the inverter switches on.
I have varified the on board IC chips they are: 1-64T429 a 3-legged device,
uln2804A Darrlington array, LM339 , LM358n op-amp, PIC16C72A 8-bit cmos microcontroller, and there are other transisters, power transisters.
I have not been able to find a schematic, I quess at this point Iam thinking that maybe the microcontroller is sensing the presence of ac and the loss of ac and then activating the inverter some how, does any one out there have any advice or ideas?
