How do I select an inrush current limiter?
How do I select an inrush current limiter?
Inrush Current Calculators are the best way to measure the resistance versus temperature curve to get the right Inrush Current Limiter. Switching power supplies, DC motors, and lighting ballasts can develop extremely high peak inrush current at turn-on unless you implement inrush current protection.
How do you calculate the resistance of a current limiting resistor?
R = V/I = 1.3V/0.015A = 86.67\Omega . In practice, it can be difficult to obtain a resistor with a resistance of precisely 86.67 Ω.
What does an inrush current limiter do?
An inrush current limiter is a component used to limit inrush current to avoid gradual damage to components and avoid blowing fuses or tripping circuit breakers. Negative temperature coefficient (NTC) thermistors and fixed resistors are often used to limit inrush current.
How much is inrush current?
As previously mentioned, inrush current is the maximum peak current, experienced in the system and it can be twice or ten times of the normal rated current. This unwanted current spike can damage the device like in transformer, inrush current can cause tripping of the circuit breaker, every time it turns ON.
What is Max inrush current?
Inrush current is the maximum current drawn by an electrical circuit at the time it’s turned ON. It appears for the few cycles of input waveform. The value of the inrush current is much higher than the steady-state current of the circuit and this high current can damage the device or trigger the circuit breaker.
What is the need for current limiter circuit in a regulator?
The function of current limiting circuitry is to prevent damage to the IC when an overload is placed on the output of the regulator (the load impedance is too low). Without current limiting, the regulator would source excessive load current and destroy the pass transistor inside the part.
What is the cause of inrush current?
Inrush current is the instantaneous high input current drawn by a power supply or electrical equipment at turn-on. This arises due to the high initial currents required to charge the capacitors and inductors or transformers. These currents can be as high as 20 times the steady state currents.
What is NTC capacitor?
NTC thermistors are temperature-dependent resistors that employ special semiconductor ceramics with a negative temperature coefficient (NTC). NTC thermistors used as current protection devices are also called power thermistors. A fixed resistance or an NTC thermistor can be used to limit inrush currents.
What is inrush current limiter?
It is called an inrush current, and without protection, it may destroy a semiconductor device or have a harmful effect on the service life of a smoothing capacitor. NTC thermistors are used as ICLs (inrush current limiters) to protect circuits of electrical and electronic devices against inrush currents easily and effectively.
What is inrush current and what causes it?
Inrush current occurs when power is applied to a circuit, in particular circuits with capacitive loads. As the capacitive load charges it creates a current spike, and corresponding voltage dip on the power supply input, due to the internal resistance of the battery or power supply.
How does a current limiting resistor work?
A current limiting resistor regulates and reduces the current in a circuit. This equation and calculator helps determine the value of the resistor to add to a light-emitting diode (LED) so that it can limit the current moving through the LED. The calculation also determines how much power the LED consumes.
What are the applications of NTC thermistors for inrush current limiting?
The following are details of sample applications of NTC thermistors for inrush current limiting. Various switch-mode power supplies (SMPS) – which are small, lightweight, and high-performance – are often used as power supplies of electronic devices.
