Does DC current have a frequency?

Question

I am importing an eletronic device from japan, the post office requires me to fill out the frequency and power output for the device for me to recieve it, i asked the manufactures, they said since the device is battery powered (DC12V, 6A) it does not have an output frequency, Any eletrical engineers?thanks.

ok thanks,...and the power output of this device would be?....72watts?(12v x 6amps)?

Answer 1

The power output is 12 Volts. Volts measure the force by which electricity flows.

"DC" stands for "Direct Current," which has no frequency. The other type of electric current is "AC" ("Alternating Current"), in which the current is delivered in a series of pulses that occur at a certain frequency (such as 60 per second).

The "6A" means 6 "amps". Amps measure the volume of electricity that is flowing.

Think of electricity like water flowing in a river. If the river tumbles over a waterfall, it will flow with great force (Volts). However, if the river is just a tiny stream, you would not get hurt standing under the waterfall due to the small volume of water (Amps).

Power is sometimes measured in Watts. A "Watt" measures the amount of work that can be done. A Watt is simply Volts multiplied by Amps. A device that pumps uses a lot of Watts can do a lot of work and will also raise your electric bill.

Answer 2

Since you don' t say what the device is or does, I'm not sure just what you mean about the "output." It may be that the post office just assumes the worst and makes everybody fill in the same form even if it doesn't really apply. That's what it looks like happened to you.

DC (direct current) is the current that we get from a battery. It flows in only one direction at a constant current flow, and therefore it has no frequency.

AC (alternating current), is generated by machine-driven devices like alternators and public-power generators, and it flows back and forth in the power lines. It's wavelength is pretty big--about the distance across the US--because its frequency is low, only 60 Herz here in the US. We use this strange stuff because we can do much more with it. We can transform it much more easily (transformers do not work on direct current), and by making it one-phase to three-phase current (that is, it acts as though its really three currents all alternating at slightly different times) we can produce more consistent power in different motors and produce a more "smooth" waveform on the power you get in your home.

That's why AC is used just about everywhere. We can turn it into smoother DC more easily, and we can run it through a transformer to raise the voltage and therefore send it farther with less power loss (as a percentage of its supply voltage) and produce the power you use in your home much more efficiently. Let's say that you lose 50 volts of the power the power company generates by the time it gets to your home. If they made 120 volts, you'd only get 70 volts out of the outlet on your wall. Not good for running 120-volt appliances. Your computer and laser printer would not be happy.

But if they generated 12,000 volts, it would still be 11,950 volts which they could transform down to 120 very easily.

Of course, the transformers also need the right frequency to work well, otherwise they could overheat, and if you ran European 50 Herz appliances here, the clocks would run too fast and some devices would burn out.

Now, solid-state devices do not use AC. They all need low-voltage DC to work, so you need to do one of two thngs: either transform the power down to, oh, 5 volts (or whatever the devices are designed to use. 12 volts is also a common level) and then rectify it to DC...

...or use a battery of the right voltage. Since batteries produce DC they can be used directly in solid-state electronic devices because they produce electricity with no frequency.

This is only the start of a discussion on electricity, which--like so much of the world--is a lot stranger than we think, and therefore a lot more fun to learn about than we believe. I hope that it sparks your interest to study electricity a bit more, because it really is fun to learn about.

Answer 3

The frequency of a truly dc device would be 0 Hz

Answer 4

Direct current doesn't have a frequency. AC or Alternating current does. The number of times it alternates between negative and positive in one second is the frequency.

Answer 5

frequency implies waves, one after another. How frequently they come is the frequency. DC is constant, not frequent...