2007-02-22 20:37:49 · 10 answers · asked by thangaraj n 1 in Science & Mathematics ➔ Engineering
DC power or DC motors or DC machines require DC power. DC power is used as mentioned above DC motors are used in servomechanisms and automatic control for instance. DC macines are used with DC motors or DC power supply.
2007-02-22 21:29:48 · answer #1 · answered by Mesab123 6 · 0⤊ 0⤋
DC is used where the supply available is DC for example on vehicles.
Mains power is AC so it is used for most applications. This wasn't always the case because DC machines were easier to control the speed (Ward Leonard). Modern electronics mean that AC is now easy to control and since DC machines tend to be higher maintenance, often containing brushes etc, AC is much preferred.
There are still a number of old industrial installations that contain DC.
The other main use of a DC machine is on generators. The rotor of a main generator requires DC which is generated by another smaller DC generator on the same shaft (excitor)
2007-02-23 00:05:55 · answer #2 · answered by Poor one 6 · 0⤊ 0⤋
If you have to send electricity across a long distance (like a few miles), AC power will lose less energy in the wires than DC power will. The electrical companies use AC power mostly for this reason. So if your machine plugs directly into the wall (and hence is powered by the electrical company which is miles away), it either needs to use AC power or it needs to have a transformer inside to convert it to DC.
Cars and handheld machines have a battery inside, the electrical power doesn't travel very far, so DC power is fine. DC power sources are much cheaper and smaller than AC power sources.
2007-02-24 13:02:45 · answer #3 · answered by Weber 1 · 0⤊ 0⤋
Most appliances you use everyday operate on DC current, even if they plug into AC current at the wall. If you where to open almost any appliance you would find that the AC power is converted to DC in a "power supply" before being unleashes on electronic devices. The reason we transmit power as AC is two fold generators usually produces power in AC and AC currents travel with less loss over long distances.
However the common incandescent light bulb, without which a lot of new technology would not have been possible, is an AC appliance.
2007-02-23 01:24:38 · answer #4 · answered by Brian K² 6 · 0⤊ 0⤋
As we know that the AC power can not be stored in batteries but DC can be stored. The DC machines are used where there isn't any facility of AC supply. The DC machines are also used where the DC power is needed for example DC generator is used to get DC voltage for used of DC electronic devices or storing DC power in batteries.
2007-02-22 21:03:47 · answer #5 · answered by Anonymous · 0⤊ 0⤋
AC machines and AC power is cheaper than DC Machine and DC Power. But speed and torque control of DC machine is more easier than AC machines. Though Ac machines also can be controlled by new drives. We use both machines as per our priority. I railway the D.C. series Motor is used to control the Speed and torque as well. In industries most of the Motors are A.C. whose speed is controlled by various type of drives.
2007-02-23 08:14:36 · answer #6 · answered by J.L. S 3 · 0⤊ 0⤋
We use dc machines mostly in laboratories.
We use ac in our day to day life mostly.
Which class you're?
2007-02-22 23:43:05 · answer #7 · answered by M.R.GANESAN 1 · 0⤊ 0⤋
Neither to get AC to DC they use ''rectifiers'' DC is fit while you evaluate which you should strike a ark less difficult and that is purifier welding frequency is 60hz alongside with polarity, the transformers would not have a polarity via fact their polarity differences 60x in line with sec. i think of yet i'm now no longer particular...present day is ''amps''? Volts vs amps? i'm no proficient... you could weld 6volts@200amps/2volts@400amps iv equipped them out of microwave transformers with the aid of means of rewinding the secondary's on 4 fatboys. Welder at no fee!
2016-11-25 01:32:10 · answer #8 · answered by zoelle 4 · 0⤊ 0⤋
A very good question. Primarily the decision is based up on the system ac or dc.
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2007-02-23 22:27:20 · answer #9 · answered by liketoaskq 5 · 0⤊ 0⤋
ok...practically?...industry uses a.c. mostly. There is a movement these days to a.c over d.c. machines where VSD's (variable speed drives) are used to allow for speed control.
To generalize: day-to-day a.c. machines are used in "plug in" type appliances at home and in industry and d.c. machines used where small battery operated motors are needed..toys etc.
A simplistic overview I must admit but: the move to a.c. motors with drive control is replacing traditional d.c. applications.
2007-02-23 18:20:26 · answer #10 · answered by Anonymous · 0⤊ 0⤋