a power adapter rated 9V 500mA 4.5VA is it

A power adapter rated 9V 500mA 4.5VA is it going to do damage to a device that may use a power adapter rated 9V 500mA 6.75VA ?

geek_olack, Mar 19, 12:37 am

The 4.5VA power adapter powered up the device because the LEDs lit up but then I thought, gee is this the proper adapter. I since found out the specifications of the genuine power adapter is the different only in the VA of 6.75VA.

geek_olack, Mar 19, 12:43 am

it won't be powerful enough. won't do any damage to the unit you are trying to power up - but the adapter itself will end up cooking.

geek_blitzem1, Mar 19, 1:00 am

Thankyou ...blitzem1

geek_olack, Mar 19, 1:39 am

I might experimentgzzzzch!

geek_olack, Mar 19, 2:54 am

I actually had this similar situation before with my old laptop needing a new power adapter. Old adaptor was 6.75, the new one was 4.5 ...and new one works perfectly. I tried to be smart and swap the power cables from the old one into the new one and "POW"..my new adapter exploded into two pieces...had to order a new one in.

geek_deus701, Mar 19, 7:42 am

The VA rating is the maximum power that can be continuously drawn from that power adapter, and is calculated by VA (Watts) = V x A, ie; 9volts x 1/2 Amp = 4.5 VA(Watts). Your laptop expects 9volts, and so long as it doesn't suck more than 1/2 amp (=500mA) then either adapter is just as good as the other. But, you say, how come one is rated at 6.75 VA(Watts)? Because as you continue sucking more current out of this adapter beyond 1/2 amp, the voltage will drop. For example, if you could suck 1.125 amps, the voltage might be 6 volts = 6.75 VA(Watts) and this would still be within the design rating of this adapter. On the other hand, the other adapter would not be able to provide 1.125 amps at 6 volts, it would be beyond it's design limits and would overheat.

geek_gyrogearloose, Mar 19, 11:20 am

Gyrogearloose...I want to use the adapter as a recharging adapter. It fits a Plantronics desktop device for recharging a bluetoth headset. Also, I just now found I have a DSE 3V to 12V 500mA like the required adapter but it does not mention any VAC....thankyou for the lesson gyrogearloose.

geek_olack, Mar 19, 10:45 pm

Believe t or not that word in the my last post is ..bluetooth.

geek_olack, Mar 19, 10:48 pm

And...I just "read" your postThe VA rating is the maximum power that can be continuously drawn from that power adapter, and is calculated by VA (Watts) = V x A, ie; 9volts x 1/2 Amp = 4.5 VA(Watts)thankyou.

geek_olack, Mar 19, 10:49 pm

Err VAC = Volts Alternating Current

geek_lostdude, Mar 19, 10:51 pm

...which means that the 12V 500mA...is rated 6VAC almost the 6.75VAC of the original power adapter for the device.

geek_olack, Mar 19, 11:10 pm

Well, in this case I may use either of these power adapters and see how I get on without the .75VAC . I think I will not use the variable power adapter just yet...gzccccch!..I like the way the spelling of that word came out...

geek_olack, Mar 19, 11:14 pm

LOL, yeah ok, even though my post has nothing to do with wattagecarry on soldier.

geek_lostdude, Mar 19, 11:25 pm

Youcan't use more Volts If the amps drawn are more than
specified & less ma wont work.More
ma will fry your capacitors,as I've
found through experience.But I was using a processor with a m/b so it
fried.Oh dear,where's that warranty

geek_deodar, Mar 20, 12:25 am

FYI onlyVA is onlythe same as Watts for resistive loads. The VA rating is made to allow for inductive and capacitive loads. All that means Olack is that the higher rating can supply more current into those type of loads. You should be all right if you a) keep the voltage the same b) the supply current the same or greater c)It doesn't get too hot at high load [such as charging a flat battery]. As Deo has mentioned, DON'T try and adjust the VA but going higher in voltage as it will damage things.

geek_pheonix, Mar 20, 7:33 am

Ok, thanks, its all settled...I use the adapter I ...guessed was the original. I tried it today and it got a little warm in about 10 minutes. The DSE variable power adapter I mentioned does not get warm in the same time. But I get a bit scared with the battery powered drill charging its battery in the proper adapter...that almost gets hot.

geek_olack, Mar 20, 2:00 pm

If you can't hold your hand on it, then it's too hot. It might also smell bad, and sometimes this helps you locate which device or part of a device is running too hot.

geek_gyrogearloose, Mar 20, 2:10 pm

If I've got a DC4.5v appliance and I use a 9v 500mA 4.5VA adapter will it blow the appliance??

geek_james, Jul 21, 6:21 am