OPTOELECTRONICS


How to choose the right dimmer for LED lighting


Light dimmers, once a simple accessory for incandescent bulbs, have become more complex with the widespread adoption of LEDs.


M


any problems associated with dimmers today do not stem from failure, but from mismatches between modern LED technology and outdated dimming methods. Understanding the basics of how LEDs work and the available dimmer types helps avoid 


   Adjusting brightness was as simple as reducing current, though this resulted in part of energy being wasted as heat. LEDs, by contrast, are semiconductors that emit light when electrons release energy in the form of photons. Because they require direct current, modern LED bulbs contain small converters that transform household AC into regulated DC. LED strips use external drivers (power supplies), typically operating at 12V or 24V DC.


“


Even though


installing a dimmer may seem simple, incorrect wiring can lead to costly repairs.


 on and off at high frequency, varying the ratio between “on” and “off” states to control   Other dimming techniques include:


•


This shift means LEDs are effectively electronic devices, and their response to    with incompatible dimmers.





Traditional dimmers controlled brightness by  


34 SEPTEMBER 2025 | ELECTRONICS FOR ENGINEERS ” •


 powered drivers.


 power on the AC side by cutting the waveform at the rising (leading) edge or declining (trailing) edge – pictured on next page.


 cut dimming, particularly cheaper models   failure.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46