Search results
Results from the WOW.Com Content Network
An inrush current limiter is a device or devices combination used to limit inrush current. Passive resistive components such as resistors (with power dissipation drawback), or negative temperature coefficient (NTC) thermistors are simple options while the positive one (PTC) is used to limit max current afterward as the circuit has been operating (with cool-down time drawback on both).
A simple solution is to add electrical impedance to the circuit. This limits the rate at which current can increase, which limits the level the fault current can rise to before the breaker is opened. However, this also limits the ability of the circuit to satisfy rapidly changing demand, so the addition or removal of large loads causes unstable ...
When the circuit is closed, the thermistor's resistance limits the initial current. After some time, current flow heats the thermistor, and its resistance changes to a lower value, allowing current to flow uninterrupted. It is inherently impossible for 100% of supply voltage to appear on the protected circuit, as the thermistor must continue ...
Figure 1: Schematic of an electrical circuit illustrating current division. Notation R T refers to the total resistance of the circuit to the right of resistor R X.. In electronics, a current divider is a simple linear circuit that produces an output current (I X) that is a fraction of its input current (I T).
Current limiting reactor. The main motive of using current limiting reactors is to reduce short-circuit currents so that circuit breakers with lower short circuit breaking capacity can be used. They can also be used to protect other system components from high current levels and to limit the inrush current when starting a large motor. [5]
Unlike an SCR, an SCS can be triggered into conduction when a negative voltage/output current is applied to that same lead. SCSs are useful in practically all circuits that need a switch that turns on/off through two distinct control pulses. This includes power-switching circuits, logic circuits, lamp drivers, and counters.
Liquid earthing resistor, 33 kV, 21 ohms, rated for 750 amps for 10 seconds, providing an earth path for the tertiary winding of a 275/132/33kV autotransformer. A common use in the electrical power generating and distribution industry is as a fault current limiter in the common neutral leg of large three-phase transformers and generators.
A simple electric circuit made up of a voltage source and a resistor. Here, =, according to Ohm's Law. In the theory of electrical networks, a dependent source is a voltage source or a current source whose value depends on a voltage or current elsewhere in the network.