power consumption?

[ivtec]

Hi guys:i bring up this topic because i came across a forum that discussed the power consumption of Satellite Receivers on Standby,and somebody there said that the receivers consume as much power if receiver stays on standby as it consumes when turned on.So i went ahead did some calculations on my 322 receive,and came up with these numbers,i may be wrong on my calculations correct me if I'm wrong!.
With my Fluke 87 measured 0.236miliamps turned on,and 0,226
in standby,

on standby 120v/0.226=530 Ohms,120x120=14.400/530=0.027watts.
turned on 120v/0.236=508 ohms,120x120=14.400/508=0.028watts.

i don't know if these #s are correct, but if they are than the power consumption is very low and is not that bad,if not than this receivers are not green at all,because no matter what kind of equipment they shouldn't waist as much energy on standby as in on mode.So anybody here is an expert enough to refute my numbers?

[Wizard]

Re: power consumption?

.226A means milliamps and you multiply by volts to get VA power not divided since this is AC not DC.

http://en.wikipedia.org/wiki/Volt-ampere

226mA x 120VAC = 27.1 VA (watts)

236mA x 120VAC = 28.3 VA (watts)

So you are only have 1.2W difference. Meant this box is not in true standby, just active to keep catalog updated by downloading and checking via cable.

These guys are right this seems to be.

Cheers, Wizard

[Gianni]

Re: power consumption?

I have not tested SAT receiver but DVBT Receiver and I saw that they consume the same power in Stand-by and when they are working (~10W). I did the test in my office with a PFC meter.
I think these Boxes (SAT - DVBT) just cut the video output while they are in stand-by... but anything else is working for the reason explained by Wizard.

ivtec I think you have to multiply the result 236mA x 120VAC = 28.3 VA for a coefficient of 0.63, so the active power is ~18W.
0.63 is the typical power factor value for PSU that have not PFC and 18W seems to me a more realistic value for a SAT Receiver.

Ciao
Gianni