Dc power supply of steady voltage current is formed in the hold circuit device.
Such as batteries, battery, dc generators, etc.
Dc power supply has both positive and negative electrodes, the anode potential of the high and low potential of the cathode, after the two electrodes and the circuit is connected, able to maintain a constant potential difference between the circuit at both ends, thus in the external circuit formed by the positive to the negative current.
Dc power is an energy conversion device, it convert to other forms of energy to power supply circuit, in order to maintain a steady flow of current.
He is the basic principle of electrostatic field generated by electric charge alone cannot sustain stable constant current, and by using dc power supply, can use the electrostatic interactions (
For short & other;
The electrostatic force & throughout;
By making positive charge by the cathode potential low power internal returns to the high potential was beyond cure, in order to maintain the potential difference between two electrodes, and thus form a steady electric current.
Dc power supply of the electrostatic force is points from the cathode to the anode.
When the dc power supply after connected with external circuit, and on the outside of the power supply (
, because of the push of the electric field force, formed from the positive to the negative current.
In the power supply inside (
In the circuit)
The role of the electrostatic force makes the electric current to flow from the cathode to the anode, which makes the flow of electric charge form a closed loop.
Performance power itself is an important characteristic of the power of the electromotive force, it is equal to the charge from the cathode by power supply inside the electrostatic force of the work to the anode.
When the power supply of the internal resistance can be ignored no time, can think the power of electromotive force on the value approximately equal to the power or voltage potential difference between the poles.
In order to obtain high dc voltage, often will use dc power supply series, the total electromotive force is the sum of electromotive force of the power supply, total resistance is the sum of the power source internal resistance.
Due to internal resistance increases, in general can only be used for smaller circuit current strength required.
In order to obtain larger current strength, electromotive force, such as dc power may be connected in parallel, then the total electromotive force is the electromotive force of a single power supply, total internal resistance of the power of the internal resistance in parallel.
Dc power supply many types, different types of dc power supply, the electrostatic force of different nature, the process of energy conversion is also different.
In the chemical battery (
Such as batteries, battery, etc. )
In the electrostatic force is associated with ion dissolution and deposition process of chemistry, chemical battery discharge, the chemical energy into electricity and power supply (joule heat on the temperature difference
Such as metal thermocouple, thermocouple semiconductor)
In the electrostatic force is associated with the temperature difference and electronic concentration difference of diffusion effect, thermoelectric power supply to provide power to external circuit, heat part is converted into electrical energy.
In dc generator, the electrostatic force is electromagnetic induction effect, direct current generator power supply, the mechanical energy into electrical energy and joule heat.
In photovoltaic cells, the electrostatic force is a function of photovoltaic effect, photovoltaic cells, the light energy into electrical energy and joule heat.