My surveilance cam power adapter label states 5v==1A. I am not an electrician, but is it right to say that based on tha label, to compute for Power (watts) consumed by the device:

1A x 120 volts = 120 watts

For electricity consumption:

120 watts X 24 hours= 2,880 watt-hrs per day
2,880 watt-hrs per day / 1000= 2.88 kwh per day
2.88 kwh per day x 31 days =89.28 kwh per month
89.28 kwh per month x $.10 per kwh= $8.928 per month

Does that mean that I am spending $8.92 per month for a small camera?

Thanks
Luke

 

The label probably means 1A at 5V. If you can post the brand and model we can give you more info. If it was consuming 120w it would be really hot. A 120w light bulb is probably similar size (similar surface area), think about how hot a 120w light bulb gets..

 

1 amp at 5 volts, or less

 

No. Your camera is taking 1A @ 5V = 5W max.
It could be much lower than that. You can get a better estimate by measuring the current with a meter or the wattage with a mains power meter.

 

You must not confuse input power and output power. Here is where the term efficiency comes to play. Assuming the worst load scenario, output power is 1A x 5V = 5W max.

 

The only way to actually know how much power is consumed is to measure it. The 5 volt 1.0 amp is merely what the power supply is capable of delivering which expressed as power is 5 watts as mentioned.

Does that mean that I am spending $8.92 per month for a small camera?

No, not at all. Likely not even close.

Per Mr. Chips a simple way to measure and a nice device to have around is a P3 P4400 Kill A Watt Electricity Usage Monitor. One of the more handy little gadgets I have laying around here.

Ron

 

Chances are the camera is using only about 50-75% of the adapter rating, which would give a camera power consumption of 2.5W-3.75W.
Assuming the adapter is 85% efficient, the power from the mains would be 2.9W-4.4W.

But the best way to determine the power consumption is a main's power meter, as suggested by MrChips and Ron.
I have a Kill-A-Watt unit myself and they are a fun gadget to have if you are interested in knowing the power consumption of various appliances, even if if doesn't save you money. They also measure other things such as power-line voltage and frequency, and the load VA and power factor.