29-11-2020, 11:10 AM
(This post was last modified: 29-11-2020, 11:14 AM by ppppenguin.)
I also had a dimmer pack up the other day. It was a trailing edge type, suitable for LEDs, but quite old. It was an odd fault. It would dim the lights to zero from time to time, for no reason. It would reset if you switched it off and on. Eventually it did it too frequently so I replaced it.
Conventional leading edge dimmers use a triac and chop off the first bit (leading edge) of the sine wave. The triac is turned off at the zero crossing. This works badly with small loads like LEDs. Trailing edge dimmers use a FET so no commutation needed. They are more complex and more expensive.
LED lamps are mostly very good now. From the £1 types at Poundland upwards. B&Q have a very good range. The 1520 lumen lamps are equal to or better than an old 100W GLS. Colour rendering is generally good too. If you want to dim them, make sure you get dimmable types. They don't dim quite so well as GLS. They won't go to near zero light but amply good enough for most purposes. Also if you have a mix of types (different makes of LED, or LED+GLS) on a single dimmer they won't always dim at the same rate.
Conventional leading edge dimmers use a triac and chop off the first bit (leading edge) of the sine wave. The triac is turned off at the zero crossing. This works badly with small loads like LEDs. Trailing edge dimmers use a FET so no commutation needed. They are more complex and more expensive.
LED lamps are mostly very good now. From the £1 types at Poundland upwards. B&Q have a very good range. The 1520 lumen lamps are equal to or better than an old 100W GLS. Colour rendering is generally good too. If you want to dim them, make sure you get dimmable types. They don't dim quite so well as GLS. They won't go to near zero light but amply good enough for most purposes. Also if you have a mix of types (different makes of LED, or LED+GLS) on a single dimmer they won't always dim at the same rate.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
