LED lamp EMC case study

LED lamps are avail­able in var­i­ous shapes and con­struc­tions. Design is usu­ally defined by the appli­ca­tion of LED lamp. In this arti­cle con­struc­tion of sim­ple office lumi­nary is exam­ined and main emis­sion sources determined.

Office LED lamp

Office LED lamp, close look

Office LED lamp with­out pro­tec­tive cover

LED arrays are mounted directly on LED lamp enclo­sure (with­out insu­la­tion), so enclo­sure acts as heat sink. All LED arrays are con­nected in series and con­nected to LED dri­ver DC out­put. In front of LED dri­ver there is EMI fil­ter. This fil­ter pro­to­type was added by man­u­fac­turer after­wards they has bought coupe hun­dreds of “cer­ti­fied” LED dri­vers, assem­bled cou­ple of LED lamps and sent to EMC lab­o­ra­tory, LVD lab­o­ra­tory and after­wards to cer­ti­fi­ca­tion. The only solu­tion to get LED lamp cer­ti­fi­ca­tion was to add exter­nal EMI fil­ter. Other solu­tion was to donate all LED dri­vers for uni­ver­si­ties to edu­cate new engi­neers, how not to design LED drivers.

Sin­gle LED lamp, with­out EMI fil­ter, radi­ated emis­sions were high enough to damp all radio sta­tions in 5m range. If such LED lams were installed in office, there could be high prob­a­bil­ity that some of office equip­ment were fail­ing, due to elec­tro­mag­netic inter­fer­ence. If such LED lamps were installed in hos­pi­tal or other health care insti­tu­tions, there could arise death threat­en­ing sit­u­a­tions (depend­ing on the EU coun­try, it can lead up to long term prison sen­tence for LED lamp dis­trib­u­tor). Another thread to man­u­fac­turer, who retails such un-​compliant LED lamps, is mar­ket sur­veil­lance com­pa­nies, who react on cus­tomer claims and ver­ify mar­ket ran­domly tak­ing out and test­ing samples.

LED lamp radi­ated emis­sions with­out EMI fil­ter

LED lamp radi­ated emis­sions with man­u­fac­turer designed EMI fil­ter

RF EMC DEVEL­OP­MENT team was assigned to this case to opti­mize LED lamp EMI fil­ter design, as man­u­fac­tur­ers pro­to­type design price was equiv­a­lent to LED dri­ver price. The size of EMI fil­ter was too big and radi­ated emis­sions was too close to limit line. RF EMC DEVEL­OP­MENT had two solu­tions, inte­grate cou­ple of pas­sive com­po­nents inside the LED dri­ver or add extra fil­ter at the AC input of LED dri­ver. As LED lamp man­u­fac­turer, due to sim­plic­ity, chose to add exter­nal EMI fil­ter. RF EMC DEVEL­OP­MENT team devel­oped fil­ter pro­to­type, con­sist­ing of few low-​cost com­po­nents, which decreased LED lamp total price and decreased radi­ated emissions.

Office LED lamp with RF EMC DEVEL­OP­MENT opti­mized EMI fil­ter pro­to­type

LED lamp radi­ated emis­sions with RF EMC DEVEL­OP­MENT designed EMI fil­ter pro­to­type

RF EMC DEVEL­OP­MENT team rec­om­mends to make pre­com­pli­ance tests for LED lamps and LED lamp dri­vers before send­ing them to cer­ti­fi­ca­tion and accred­ited test­ing. It is a lot cheaper to make pre­com­pli­ance tests than make repeated accred­ited test­ing and cer­ti­fi­ca­tion.

RF EMC DEVEL­OP­MENT offers EMC pre­com­pli­ance test­ing, accred­ited test­ing and devel­op­ment for LED dri­vers, LED lamps and other light­ing equip­ment. We can pro­vide eval­u­a­tion of LED dri­vers qual­ity, before they are installed in LED lumi­nar­ies and give recomen­da­tions.

EMC test­ing

RF EMC DEVEL­OP­MENT pro­vides accred­ited EMC test­ing to reach Euro­pean mar­ket. We hold a long list of Euro­pean stan­dards for such indus­tries as– house­hold, indus­trial, auto­mo­tive, med­ical, tele­com, rail­way and aero­space. Our test lab­o­ra­tory is accred­ited by Euro­pean noti­fied bod­ies accord­ing to ISO17025. Save your time by try­ing to cou­ple EMC test­ing with other tests and CE cer­ti­fi­ca­tion needs (safety, envi­ron­men­tal, energy effi­ciency, performance).


Through our part­ners, noti­fied bod­ies in Euro­pean Union, RF EMC DEVEL­OP­MENT pro­vides cer­ti­fi­ca­tion ser­vices for man­u­fac­tur­ers, retail­ers, dis­trib­u­tors and sup­pli­ers to enter EU mar­ket. We pro­vide all ser­vices to cer­tifi­cate your prod­ucts in short time span– EMC test­ing, LVD test­ing, devel­op­ment for such prod­ucts as: light­ing equip­ment, auto­mo­tive, con­sumer elec­tron­ics, indus­trial elec­tronic and machin­ery, med­ical equip­ment, telecom­mu­ni­ca­tions and wood­work­ing equip­ment etc.

eXTReMe Tracker