Bissoy.com
Doctors Medicines MCQs Q&A

What is the use of an LED driver?

What is the use of an LED driver? Correct Answer It converts AC to DC

An LED driver is a self-contained power supply that regulates the power required for an LED or array of LEDs. 

  • Constant current LED drivers are designed for a designated range of output voltages and a fixed output current (mA). LEDs that are rated to operate on a constant current driver require a designated supply of current usually specified in milliamps (mA) or amps (A).
  • Constant voltage LED drivers are used for LEDs that require one stable voltage and have a current that is already regulated either via simple resistors or an internal constant current driver.

The output of LED is either constant voltage or constant current (DC). 

[ alt="26 June 1" src="//storage.googleapis.com/tb-img/production/19/08/26%20June_1.png" style="width: 160px; height: 46px;">

LED drivers applications:

1) The change in forward voltage of LED with the change in temperature can cause the LED to burn out, this is also known as Thermal Runaway.

2) LED drivers prevents damage to LEDs as the constant current LED driver compensates for the changes in the forward voltage while delivering a constant current to the LED.

3) Thus LED drivers, convert higher voltage, alternating current to low voltage, direct current, and

4) It keeps the voltage or current flowing through the circuit at its rated level.

Related Questions

Three friends want to hire a taxi for a trip. The taxi owner provides them with following three options: A. You can hire the taxi without an accompanying driver. This would cost you Rs. 2500 per day. Driver can be arranged from another agency for Rs. 500 per day. B. You can hire the taxi with driver from the first agency. This would cost you Rs. 2800 per day. But driver will have to be provided relief fund of Rs. 250 per day if total distance traveled exceeds 1500 KM. C. You can hire the taxi without an accompanying driver. This would cost you Rs. 2500 per day. Driver can be arranged from another agency for 50 paise per KM.  If the friends plan to travel to a place at a distance of 1500 kms and come back the next day, which tariff option should they choose? 
Three friends want to hire a taxi for a trip. The taxi owner provides them with following three options:  A. You can hire the taxi without an accompanying driver. This would cost you Rs. 2500 per day. Driver can be arranged from another agency for Rs. 500 per day.  B. You can hire the taxi with driver from the first agency. This would cost you Rs. 2800 per day. But driver will have to be provided relief fund of Rs.250 per day if total distance traveled exceeds 1500 KM.  C. You can hire the taxi without an accompanying driver. This would cost you Rs. 2500 per day. Driver can be arranged from another agency for 50 paise per KM.  If they had planned to travel total of 6000kms in 5 days. Which option would have been better? 
The average weight of 20 boys is 22.5 kg and that of 25 girls is 18 kg on a school bus. The average weight of all 45 students is equal to the 1/3rd of the weight of the bus driver. What is the change in the average weight of the bus including the driver if the old driver is changed with a new one whose weight is 6 kg more than the old driver?
With reference to street-lighting, how do sodium lamps differ from LED lamps? 1. Sodium lamps produce light in 360 degrees but it is not so in the case of LED lamps. 2. As street lights, sodium lamps have a longer life span than LED lamps. 3. The spectrum of visible light from sodium lamps is almost monochromatic while LED lamps offer significant colour advantages in street lighting. Select the correct answer using the code given below.  
What is the difference between a CFL and an LED lamp? 1. To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semiconductor material. 2. The average life span of a CFL is much longer than that of an LED lamp. 3. A CFL is less energy-efficient as compared to an LED lamp. Which of the statements given above is/are correct?
What is the difference between a CFL and an LED lamp? 1. To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semi-conductor material. 2. The average life span of a CFL is much longer than that of an LED lamp. 3. A CFL is less energy-efficient as compared to an LED lamp. Which of the statements given above is/are correct?
What is the difference between a CFL and an LED Lamp?
1. To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semi-conductor material.
2. The average life span of a CFL is much longer than of an LED lamp.
3. A CFL is less energy efficient as compared to an LED lamp.
Which of the statements given above is/are correct?
The fine for a driver riding in the carpool lane without any passengers is $ 133.A driver is issued a b ench warrant for # 2,29.25 which includes a 15% fee for late charges and court costs. How many tickets has the driver not paid?
Studies of fatal automobile accidents reveal that , in the majority of cases in which one occupant of an automobile is killed another survives, it is the passenger , not the driver , who is killed. It is ironic that the innocent passenger should suffer for the driver's carelessness, while the driver often suffers only minor injuries or none at all. Which of the following is an assumption underlying the reasoning in the passage above?
In a cab service app, 25% before tax earning has to be paid as commission to the app by the driver. Further if the app management launches any offer, only 60% of the cost of offer will be borne by the management and remaining to be taken from the driver. After the discount 18% tax is levied. If the customer obtains 20% offer and pays Rs. 377.6. How much does the driver get paid? (in rupees)