UPS contactor problem

[andrew2022]

i have a trust UPS800 which i have modified (i.e added 200AH worth of batteries to the 7AH it came with and added a few cooling fans. i have also fed it thru a 2NO+2NC contactor so i can switch off the UPS and run direct from mains. the UPS is rated 480W output and the computer (comp, 1 monitor, modem and router) draw about 180W. problem is, if the monitor is off and i switch it on whilst running from battery, the contactor drops for a split second but enough to reset the comp. is there an easy way to stop this happening?

EDIT: ill try swapping the monitors later, since 1 is newer and uses slightly less power

 

[2ny]

if the monitor is off and i switch it on whilst running from battery, the contactor drops for a split second but enough to reset the comp. is there an easy way to stop this happening?

hi,

easiest way would be to have the monitor on while using your pc!(is there another way?)lolz!

 

[Someone Electro]

CRT tubes need about 20kV at in the electron gun and there is a big filter cap before that.The monitor trys to fill it to 20kV im the shortest time and that takes a LOT of power.That makes an voltage slump big enugh to reset your PC.

To fix this get an LCD

In school we had this problem too back then wen we had CRT monitors there ware about 7 PCs whith monitors conected to a singe circuit breaker and if you thurned on the main switch and more than 3 monitors ware thurned on the circuti brekaer kept triping.So you have to switch them off and then flip the main pover switch then thurn on th monitors one by one.

 

[eblc1388]

Hi andrew2022,

If you can bear some minor inperfection in screen color, you can disconnect the CRT Degauss circuit, which takes enormous current and which also making the familiar "bang" noise during first power on.

I think your UPS output can then power up the monitor without problem.

You can then fit a manual push button to degauss the screen when using normal main AC power.

 

[andrew2022]

thanx for the replies people. the best way around it i have found atm is to put the comp in standby, switch on monitor then switch comp on. only takes a few seconds to standby and startup