Non-load power drain of power inverter

[C00P]

Hi Folks,
I've purchased a Targus 150W Auto/Air power inverter to provide a charging system for my laptop and also charge minor items like mobile phones, Kindle, rechargeable AAA batteries, etc. The laptop has a 240V/65W charger so the Inverter should operate well within its specifications.
I'm wondering if anyone can tell me the likely power consumption of a device like this when there is no load. When charging minor items like the Kindle (500mA max via its USB port) it will certainly not be loaded much , especially as the Kindle battery approaches capacity.
The device's manual does not include any information like this, but does have these specs: Input 12-16V dc; AC outpout 240Vac 50Hz (Modified sinewave); 150W continuous (200W surge); USB Output 5Vdc 500 mA.
Not mentioned in the User's manual supplied with the device, but in the on-line user's manual is a statement to the effect of "Period of use: 6 hours". Not sure what this means- are they suggesting it has a 6-hour duty cycle?
Any opinions from knowledgeable electronics folk gratefully received...

Coop

[JDNSW]

These devices vary in their standby load. It is probably only a few hundred milliamps, if that, and some switch off with power use down to a few milliamps and check for any load every few seconds - but in the absence of any information from the manual this is only a guess. Certainly the efficiency of the device will be very low when operating at a small fraction of its maximum output. I would disconnect it when not in use.

I would expect the six hour duty cycle only applies when operated at its rated power. But it is worth noting that this rating, and the duty cycle, almost certainly are specified at 20C, and should be significantly derated at typical Australian summer temperatures.

John

[Blknight.aus]

my old jaycar 150W unit draws 150mA on standby and double that if its pinging the alarm and running the fan.

[bee utey]

Get a multi meter, and check the current yourself???:)


"Period of use: 6 hours".

That's when the warranty runs out?:angel:

[C00P]

That's when the warranty runs out?:angel:
Yes, that did cross my mind..... :D

Thanks for all the info folks, that gives me some numbers to work from.

Coop

[PhilipA]

My Jaycar 300W pure sine wave has a switch.
AFAIR I tested the current drain and it was nil switched off.
Regards Philip A

[C00P]

Get a multi meter, and check the current yourself???:)


In case others need this information, I finally found a way to do this (had difficulty inserting a multimeter into the circuit because it uses a cigarette lighter type of plug which could not be disassembled).
The unit has an internal fan. The no load current draw was 280mA.
It will mostly be operated at about half its rated output (about 65W) so should tolerate reasonably high temps without too much trouble.
Regards

Coop

[slug_burner]

More than likely will derate instead of self destructing. Then again, who knows.

[C00P]

More than likely will derate instead of self destructing. Then again, who knows.

It claims thermal and overload protection, so will probably shut down if it overheats <crosses fingers>.

Coop