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What is reverse voltage of LED?
LEDs can be operated on an alternating current voltage, but they will only light with positive voltage, causing the LED to turn on and off at the frequency of the AC supply. Most LEDs have low reverse breakdown voltage ratings, so they will also be damaged by an applied reverse voltage above this threshold.
What is maximum repetitive reverse voltage?
Maximum repetitive reverse voltage = VRRM, the maximum amount of voltage the diode can withstand in reverse-bias mode, in repeated pulses. Maximum DC reverse voltage = VR or VDC, the maximum amount of voltage the diode can withstand in reverse-bias mode on a continual basis.
What is the maximum voltage needed for an LED to work?
VL = LED voltage (2V, or 4V for blue and white LEDs). The LED current must be less than the maximum permitted for your LED. For standard 5mm diameter LEDs the maximum current is usually 20mA, so 10mA or 15mA are suitable values for many circuits.
How do we protect LED from too much current?
A surge protection subassembly that can suppress excessive surges to lower voltage levels is an optimal way to protect the LED luminaire investment. Metal Oxide Varistor (MOV) technology is not only inexpensive but also a highly effective technology for suppressing transients in power supplies.
What happens when reverse voltage is applied to a led?
A resistor will limit the current once reverse breakdown occurs but otherwise will allow full reverse voltage to be applied to the LED. Consider the case of a high resistance resistor and series LED across mains supply.
How to calculate the minimum resistor value for an led?
To determine the minimum resistance value required, we need to know the largest possible voltage drop across the resistor along with the smallest maximum current through the resistor. In addition, we want to account for the smallest resistance value possible based on its tolerance specification.
Which is the maximum value of reverse voltage?
For rectifier applications, peak inverse voltage (PIV) or peak reverse voltage (PRV) is the maximum value of reverse voltage which occurs at the peak of the input cycle when the diode is reverse-biased.
What’s the reverse voltage of a silicon diode?
This allows the reverse current to bypass the LED, limiting the reverse voltage across it to about 0.65 V, which is within its rating. You can also use a second LED instead of a silicon diode, which will give you more light and reduce flicker, rather than letting the reverse current go to waste.