inverter voltage Q

[andrew2022]

my inverter is only givin out 215VAC whatever the input voltage is. however, if i plug my monitor in is makes a weird noise (similar to a transformer supplyin a large load), and lines appear accross the screen. also, if i plug the UPS into it, it still stays in battery mode rather than switch back to mains. i have checked the manual for the UPS and it says it will go to battery if under 180VAC, i dont have the manual for the monitor tho. could the problems be due to the lower voltage?

 

[David Bridgen]

Hi Andrew.

Have you measured the voltage when loaded?

 

[andrew2022]

tested again. voltage was 230VAC no load and 227-8 under load of 150-200W

 

[David Bridgen]

Very odd.

I wonder if the inverter is unstable? Or does it have a non-sinusoidal output which the monitor and the u.p.s. don't like?

 

[andrew2022]

Very odd.

I wonder if the inverter is unstable? Or does it have a non-sinusoidal output which the monitor and the u.p.s. don't like?

the monitor works but makes a weird noise. the UPS just doesnt seem to recognise the supply. i hav tried shortin the earth to the lives from the inverter but it still stays in battery mode. connect it to the mains and its fine. my dad has a 600W inverter at his so ill get that later on and try it with that one

 

[David Bridgen]

Well, seeing that the voltage stays more or less put when the thing is loaded that leaves either a crappy waveform or instability.

Have you got a 'scope, or can you borrow one, to look at it?

 

[andrew2022]

Well, seeing that the voltage stays more or less put when the thing is loaded that leaves either a crappy waveform or instability.

Have you got a 'scope, or can you borrow one, to look at it?

cant get one. no1 i kno has one. altho i kno someone who might have one. ill try with the other inverter first . thanx for the replies

 

[andrew2022]

next idea. i opened the UPS to see what kinda battery it was. could i connect a seperate 12VDC battery to the inverter so when there is no mains, it can take juice from the bigger battery and when the mains is on it is disconnected and charged?

also, it gets fairly hot during battery mode, and has no fans so i will be adding a nice big fan to it if i did go with thr second battery