LED Driver Frequently Asked Questions

Are GE Lightech™ LED Drivers dimmable?
At the moment we offer two families of Constant Current LED Drivers which are phase control dimmable. We offer a 'Better' product which is Trailing Edge dimmable only (also called ELV, Reverse Phase) and dims down to 10%, and at a higher price our 'Best' dimming product group will work with almost any Leading Edge (Triac, Forward Phase) or Trailing Edge dimmer and dims to less than 1%. Separately, we offer a selection of 1-10V dimmable European Constant Current LED drivers in 18W 350mA and 36W 700mA.

What type of Dimmer is capable of working with your Phase-Controlled dimmable drivers?
Our 'Best' phase-controlled dimmable drivers can be dimmed with almost any type of forward or reverse phase controlled dimmer. Our 'Better' phase-controlled dimming drivers are less expensive but only work with the more expensive reverse phase-controlled dimmers.

What's the difference between Constant Voltage and Constant Current drivers?
With Constant Voltage the LED module only requires a fixed voltage, often 12VDC or 24VDC. The current is usually regulated by either resistors that have been wired in series with the LEDs or by an onboard built-in regulator driver that the LED module may have. This arrangement is often used in signage where it is not known prior to the installation how many LED loads there will be and in linear architectural designs where there are a number of LED modules connected together. Constant voltage loads may be added in parallel across the output of the driver until the maximum output current is reached.

With Constant Current the reverse is true, the current is fixed by the driver while the voltage will vary depending on the load. The more LEDs are attached, the higher the output voltage will be, up to a maximum set by the driver. This is usually used when the load/number of LED's is known and you want optimal efficiency, as in a recessed downlight or track fixture.

How will I know whether to use a Constant Voltage or Constant Current driver with my LED's?
Usually the manufacturer of the LED load will specify whether the LED module is for use with either a Constant Voltage or Constant Current driver. You cannot run an LED module designed for constant current from a constant voltage supply without damaging it. However a constant voltage LED load will run (inefficiently) from a constant current driver. Another indication is if the LED module is rated in milliamps (mA) or volts (V). Milliamps indicates the module requires a Constant Current driver. Volts means the module is designed for use with a Constant Voltage driver.

What is THD or Total Harmonic Distortion?
THD of a signal is a measurement of the harmonic distortion present in the power line current drawn by a driver and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency What is Ripple Current? Any Driver or Ballast running from an input at 60Hz, for example, will have some minor 120Hz fluctuations on the output current. Ripple is the amount of this fluctuation expressed as a percent of the output current. The word flicker is often used with the same meaning as the word ripple.

What is Ripple Current?
Any Driver or Ballast running from an input at 60Hz, for example, will have some minor 120Hz fluctuations on the output current. Ripple is the amount of this fluctuation expressed as a percent of the output current. The word flicker is often used with the same meaning as the word ripple.

How do I wire the LEDs?
Be sure to follow the installation instructions that come with the product. When using a constant current driver it will be specified to a minimum and maximum number of LED's wired in series. With a constant voltage driver you can connect increasing numbers of LED of the specified voltage in parallel across the output until the rated maximum current of the driver is reached.

What is the warranty for an LED Driver?
Our LED drivers have a 5 year limited warranty

What is Power Factor?
This is the power being used by the driver divided by the product of the input voltage times the current going in. It's a dimensionless number between 0 and 1 where 1 is perfect.

What is the difference between Trailing Edge, TRIAC, and 1-10v Dimmers?
The most common and cheapest dimmer is a TRIAC. The down side is they generate undesirable amounts of Electro-Magnetic Interference (EMI). Trailing Edge (Reverse Phase or ELV) dimmers are more expensive but generate significantly less amounts of EMI compared to a TRIAC. In the U.S. most Trailing Edge dimmers require a neutral wire be run to the dimmer. A 0-10V dimmer uses low voltage control wires to dim; this usually requires an extra pair of wires to be run to every driver from the dimming module.

How far away can the driver be remotely mounted from the LEDs?
We are concerned only about voltage drop in the wiring between the LED driver and the LED array. Too much voltage drop can reduce light output from the LED system. The acceptable distance is determined by the load and the conductor size. With constant voltage applications you are limited since the voltage is fixed at either 12V or 24V and with a significant drop in voltage you may visually be able to see the difference in light output. A reasonable expectation is to go up to10 feet with the appropriate gauge of wire for the current. With constant current drivers there is far more flexibility since the driver will automatically supply more voltage in order to provide the necessary current. The only exception would be if the LED module was already using the entire output voltage capability of the driver, in which case the distance would be limited in a similar way to the constant voltage drivers.

Do you have 277V LED drivers?
Yes. A large proportion of our constant voltage and constant current drivers are capable of working at 277V. Please consult the Product section of the website for the latest selection of products.