Voltage Converter To Run An Ordinary Fan..?

[Thanh-BKK]

Hello.

I don't know which forum section to put this, it's about electronic but not computers... please move if required.

I need to know if it is possible to run an ordinary 220 Volts fan off one of those voltage converters which are to be used in the car, to generate 220 Volts AC from 12 Volts DC supply.

I've had frequent brief-to-long outages recently, mainly during the night, due to construction work outside (skytrain line extension) and it is next to impossible to sleep without the fan running. Running it off my computer's UPS works but it makes a horribly loud buzzing sound, i understand it's because the UPS does not output a sine form that is usable for a motor.

Hence my question - those car converters, are they suitable for a fan/electric motor? As i do have a spare car battery in my room for just that purpose (hook that to the UPS and the computer can run all day).

Many thanks in advance for replies.

Regards....

Thanh

[Guest Reimar]

Hello.

I don't know which forum section to put this, it's about electronic but not computers... please move if required.

I need to know if it is possible to run an ordinary 220 Volts fan off one of those voltage converters which are to be used in the car, to generate 220 Volts AC from 12 Volts DC supply.

I've had frequent brief-to-long outages recently, mainly during the night, due to construction work outside (skytrain line extension) and it is next to impossible to sleep without the fan running. Running it off my computer's UPS works but it makes a horribly loud buzzing sound, i understand it's because the UPS does not output a sine form that is usable for a motor.

Hence my question - those car converters, are they suitable for a fan/electric motor? As i do have a spare car battery in my room for just that purpose (hook that to the UPS and the computer can run all day).

Many thanks in advance for replies.

Regards....

Thanh

It's named Inverter and will works fine. The question is the operating time only!

Cheers.

[Tywais]

The car inverters are not that different from the UPS which also uses an inverter. The output will either be square or quasi-sine wave depending on price. This can cause problems driving inductive loads (motors) due to the harmonics and effective DC component. In other words, it can over heat the fan motor reducing its lifetime. A stepped sine or true sine (using the latter the motor will have no problems) overcomes this issue.

The motor noise using the UPS is that the inverter is outputting an unclean AC quasi-sine producing harmonics from the DC component when driving the motor's inductive load. Also the inverter itself may be damaged if not protected from inductive kickback (back emf) unless it is designed into it.

PS: The last term in the forum name is "Technology" so fits here nicely.

[T_Dog]

I would suggest that you go to your local auto parts store and buy a small 12 volt DC personal fan that drivers use on buses and in taxi trucks. You could even buy a small battery trickle charger while you are there so that your battery is always ready for an outage. If you don't feel comfortable wiring it yourself, any electrician could do it for you. Be a bit careful about keeping a lead acid battery in your bedroom though..... make sure you have good airflow, or store the battery outside. The inverters you asked about are not very efficient, and a 12V fan would run about twice as long on the same charge. Good luck!

[Thanh-BKK]

Hi.

I was thinking about such fan - as i do have a couple of those "clip on the windscreen" type small fans, however apart from a making a racket they don't do much - so i thought of getting a 12V Motor and simply replacing that in my regular fan, however where to get hold of a 12V fan motor..??

I am not afraid of electricity, one of my diplomas says "electrician" on top, the other "motor mechanic".... so no problems in that department, just - where to get the stuff..?

Now back to the inverter. Is there any way to test them, apart from taking my Hatari and my car battery to the store..? I was in Panthip today and have seen them there all over the place for as little as 350 Baht for a 150-Watts unit. I really need it only for a fan, i don't think that draws more than 40 Watts anyway. Maybe i'll just get one and try it - if it doesn't work the way it should i'll sell it again on E-Bay (previously i did not expect those things to be THAT cheap).

Kind regards....

Thanh

[Tywais]

Maybe i'll just get one and try it - if it doesn't work the way it should i'll sell it again on E-Bay (previously i did not expect those things to be THAT cheap).

At 350 Baht not a big loss plus you can always use it to power some lamps or fluorescent bulbs for emergency lighting. Take a look on the back of the inverter. Sometimes they will say not for inductive loads.