General Questions about Electricity

NW-Bound said:

1. Do you know how to calculate your base cost for electricity? Ie. can you give a single answer for the question: What was your total cost per Kilowatt Hour last month. Total cost... not the delivery, not the equalizer, not the taxes, not the contract cost or the state taxes or any other part of the confusion that could make up you electricity bill. Answer should be like this:
$.124 /KWH.

I have "Time of Day" plan that charges differently for on-peak and off-peak hours. However, last month's total cost was $208 for 1978 KWh, so the average cost was a bit more than $0.10/KWh.​

2. When you leave your desktop computer on continuously... the cost per day?

I don't leave them on 24/7. Can measure and figure out if I do that, but have not.​

3. If you have dimmer switches on your house lights, does it cost less when they are dimmed, or does the rheostat resistance offset the expected savings?
Same with fans and other variable devices.

The electronic dimmers use a thyristor that's controlled by the knob to vary the on-time during the sine-wave cycle, or the duty cycle that the device is on. So, it does cost less when dimmed.​

3. Can you put a dollar amount on the cost of operating:
- a clock radio or alarm clock.
-A TV in standby mode, vs. off.
-your cable or satellite TV Box.
-the garage door opener
-the light/clock of your microwave or electric range on you

One can figure most of this out, but I have not bothered. One thing for sure is that a garage door opener motor would use so little, because it operates for 10-15 seconds at a time, and it's for a few times a day. The phantom power to keep the wireless receiver alive takes more energy as it is on 24/7.​

4. The charger for your mobile device. Does it use electricity when it's plugged in, or just when it's charging?

There's always a bit of phantom power. I never measure, but expect it to be 1W or less. Does it feel a bit warm when plugged in? If so, it is consuming power.​

5. different question.... matching your electronic device with the correct charger:
If the original charger was 5V 1.0 Amp. Problem with using a 5V .5 amp or a 6V 1.0 amp?
Is damage likely if a 12V device is plugged in to a 9V charger, or vice versa?

Plugging in an underrated charger, meaning one with insufficient amperage, does not burn it out if the charger has built-in overload protection to save itself, which is often the case. Plugging in a 9V charger in lieu of a 12V one most likely will not work at all, as if it is not even plugged in.​

6. Wired telephones operate on 98+ volts but nearly zero amps. Info correct?

No, it's 48VDC open circuit, and at a current of 24mA when off hook. Ringing voltage is higher.​

7. Do all chargers convert AC to DC?

Yes, because all chemical batteries are DC.​

8. in an emergency, can dry cells be used to power call phones?

Yes, if the voltage is compatible.​

9. Why can't a car jumpstart a totally dead battery?

The starter may need up to 200A+. The jumpstart cable has too much resistance to supply that. Even a near-death battery can provide quite a bit of juice.​

10. Surge protector didn't protect my computer/modem/monitor/ external hard drive from nearby lightning strike. Why not?

It would have to be HUGE!​

11. What result from reversing wires in a wall socket?

The hot wire and the neutral get swapped, and some appliances may rely on the neutral for grounding. I am not sure what UL allows here.​

12. I have an emergency generator. Am told I cannot hook up to power supply junction box. Why not?

You must have a transfer switch to disconnect your home+generator from the power line. Else, you will be trying to power up the entire neighborhood, or electrocuting the utility repairman.​

13. How much of a short circuit is required to shut off the circuit breaker in my garage. Ie: dropping an electric razor in the bathroom sink? A hair dryer?
and in the same vein, why doesn't my circuit tester shut down the breaker?

Breaker's rating is usually 15A. Razor or hair dryer dropped in water won't draw that much. Same with circuit tester. DVM draws microamps, unless set in amperage mode, but then they have internal fuses. You hear a little "poof" when that happens. And if you set it in the high-current range like 10A which is not fused, then there will be BIG sparks at the probe tip!​

13. Are electronics that are battery operated, negatively affected hen running on "low batteries"?

Digital circuits go banana if power is low. Think computer crashes. So, nearly all of them like laptops and smartphones have shutdown logic. Without that, lights blink, random characters appear on screen, etc... Funny stuff, but usually no permanent damage. Well, hard drive data gets scrambled up, and that can be considered permanent damage ...​

14. Why do the USB chargers in my computer operate at different amperages than some of my chargers.

Different devices have different requirements.​

15. empirical observation ...I have bought chargers of all kinds for electronic devices... paid $.10 to $.25 each, and now have about 60 different chargers. No correlation that I can see between Volts, Amps and the plug in terminal... plus I don't understand why some chargers with the same output are very small, while others are five times the size.

Some designs are more efficient than others. Modern power circuits can be fairly small and light compared to older designs, yet handle the same power. It's done with higher switching frequencies in the DC/DC converter, but this is getting too technical.​

Am sure I am showing some ignorance here, but am sincere in wanting to know more... No easy answers online that I can find.

Yeah... slow day...

It's slow here too.​

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Silver said:

Regardless, it was nice to see imoldernu's name again. I have missed him.

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Silver said:

Regardless, it was nice to see imoldernu's name again. I have missed him.

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