Application note from Diodes Incorporated on driving 12Vac LED without smoothing capacitors with their Zetex ZXLD1360 LED driver IC and SBR2A40P1 super barrier rectifier. Link here (PDF)
LED based architectural lighting is now coming of age, but there are still some problems to be considered when designing luminaires to be fitted into existing installations.
This Application Note discusses some of the challenges and shows that the omission of the traditional smoothing capacitors has advantages in saving cost, space and PFC problems.
Important to note that it’s from 2008. Has this line: “About the best that can be done in terms of size and reasonable cost is 2 150uF 20V tantalum capacitors.” Anyone ever seen a tantalum in a LED bulb circuit? Ha ha ha… Even Philips in a recent DP post went cheapo OEM…