electricity?

Question

what is pulsating DC current?
how do you come up with it and what
applications would it have.

Answer 1

A pulsating direct current is a direct current (dc) that changes in value at regular or irregular intervals.

A pulsating direct current may change in value, i.e., be always present but at different levels, or it may be a current that is interrupted completely at regular or irregular intervals, but when present, is always in the same direction.

Diode circuit that converts alternating current into pulsating direct current.

Pulsating DC sources are usually battery chargers.

Answer 2

pulsating DC current is "DC current" that is not constant, it is "pulsing" between different amounts and possibly at differing times. It does not need to be AC current where the current flows in two different directions in the circuit ( + and -) but it has the similarity of changing strength but not polarity(direction) with respect to time. There are many ways to "come up" with a pulsating DC current and most involve a constant DC source and some type of switching or regulating device which changes the strength of the current flow, similar to a faucet or valve changes the flow, but not the direction, of water, for electric current: a switch, a transistor, or for us old guys a vacuum tube could be used. The Ignition coil on a gasoline internal combustion engine uses the on and off (pulsating) DC currentswitched by the "points" or the transistor in the ignition controller to generate the voltage for the spark plug by pulsing current through the ignition coil. An other extremely useful application is in many power supplies which change a higher DC voltage or current into a lower one by rapidly turning the higher DC supply current on and off such that the "average value" of the resulting current is lower than what the "supply" current or voltage would be. Again we can use the water faucet analogy, if certain faucet will deliver 1 liter per minute of water when turned on fully, the average flowrate, over a time longer than one minute would be 1/2 liter per minute if the faucet was turned on full for 30 seconds and then off for 30 seconds, and the same result could be achieved with a 1 second on and 1 second off cycle as well, or any other on off cycle that can be practically performed. To take it further, an on 20 sec. and off 40 sec. cycle would deliver 20/60=1/3 liter per min. This is a simple demonstration of the concept of duty cycle, where the average value of the "controlled" medium
is the ratio of the "on" time to the sum of the "on" and "off" times. many many power supplies in computers, some fluorescent lamps(with solid state ballasts) and numerous other power supplies and power controllers ( such as motor speed controllers) use this concept. The best part of all this is, if the current can be turned on and off efficiently, which it can, we have an efficient method of reducing or controlling DC with a relatively small amount of wasted energy! And of course there are many other applications of pulsating DC, but that would require way more time and space than we have here and now.

Answer 3

A direct current such as a electric fence in the mid west. It will hit & knock you down because if it was constint it would kill you becuase you would not be able to let go, and that's why they make them pulsate.

Answer 4

pulsating dc current is usually seen on gerators,especially on gas pwered ones.It is a dc current that varies.for example:one second you may have 110 volts and the next second you may have 115 volts.This is caused by the engine speeds increasing and decreasing.