120 volts by Canon Image Challenge


22-NOV-2013	Paul AKA Sparkey2

That can't be right, those are only 9 volt batteries. But it is a $400.00 meter so it must be right.

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Guest		28-Nov-2013 17:30
Yes, the AC/DC smokers are the gold standard detector. As you say the battery only is used in the event of a power failure. In addition, in my 35 years as a electrician the smoke detectors are wired interconnected so if one sounds an alarm then they all sound the alarm. Now days they have them avaliable that are wireless, never installed any myself. Paul.

Canon Image Challenge		28-Nov-2013 14:02
We have "hard wired" smoke detectors, with a battery battery backup. Are you also talking about those? We did just get our hardwired CO detector replaced. Jim

Canon Image Challenge		28-Nov-2013 13:14
I know exactly what you mean about the battery color and I almost omitted the last battery because of it but I wanted the voltage to be as close to at the 120 as possible. The reason I even have these batteries on hand is when you install or replace smoke detectors they come with cheap zinc carbon cells (shame on smoke detector mfg's". I toss the ZC batteries and install alkaline batteries in their place, that way the alkaline batteries will only have to be replaced about once in the rated lifetime of the smoke detector which is 10 years by the way. How many of you knew that smoke detectors need to be replaced every 10 years? Paul

JIK		26-Nov-2013 17:25
You probably had good time doing this picture. I like it a lot just a shame that the rear left battery isn't black for symmetry.

Canon Image Challenge		24-Nov-2013 01:32
You cheated! PA

Canon Image Challenge		23-Nov-2013 23:39
Can't wait to see the picture. Better make it a long exposure! P.S my fiance is a low volt technician in the automotive field, so I may have inquired with him what was going on in your picture =). Sierra

Canon Image Challenge		23-Nov-2013 22:25
The open circuit voltage of a fresh zinc carbon cells averages 9.6 to 9.9 volts. I have all of these because when I install new AC/DC smoke detectors in a home I always pitch the carbon batteries and install fresh alkaline batteries, that way the battery most likely will last well beyond the shelf life of the battery since it's only used for backup purpose in the event of a power failure. By the way you all know smoke detectors are only rated effective for 10 years right?? Even thought I have tested smokers and they have worked to specification 20 to 30 years of in service. Anyway this has become a new challenge now so I'm going to setup a test with the with a 60w bulb and see if it lights. Of course I'll be photographing the event. Paul

Charlie Beck		23-Nov-2013 19:43
Twelve 9-volt batteries in series should have given you 108 volts, so these must have a bit of extra kick to them. But a 120 volt DC source is essentially equivalent to a 120 volt RMS AC source. The 240 ohm AC resistance of the bulb won't be exactly the same as its DC resistance. But yes, the batteries would light up a 60 watt bulb. But I think it would not stay lit for long, before it drained the batteries of their energy. Oh, and by the way, nice shot!

Canon Image Challenge		23-Nov-2013 14:31
Very nice photo, and an interesting little experiment. Because the internal resistance of these batteries is very small, you probably need an external resistor to get a more accurate voltage measurement. Jim

Canon Image Challenge		23-Nov-2013 13:53
Sierra, I'll have to give you credit for analyzing the scene and recognizing that what you see on the meter is accurate because all the 9 volt DC batteries are in series which has a additive effect on the voltage. But more importantly I think you realized (maybe I'm wrong??) it still has the power capacity of a single cell 9 volt battery. So in reality it does not have the power to light up a 60 watt bulb. Did you take physics in HS or college? Enough of today's science lesson. Paul

Canon Image Challenge		23-Nov-2013 08:16
Nice. (someone is having way, way too much fun...lol) Traveller

Canon Image Challenge		23-Nov-2013 05:02
Now how many 60 watt light bulbs can you run on that for an hour? Sierra

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