On 28/04/2021 00:51, Cursitor Doom wrote:
On Wed, 28 Apr 2021 00:14:26 +0100, "Dave Plowman (News)"
wrote:

Think it's generally known that dimming a tungsten bulb reduced its
efficiency dramatically. In other words, a 100w dimmed to half brightness
used a lot more electricity than a 50w on full. Although dimming did
extend the life of the bulb.

So how about LEDs? Since they generate far less heat are they still as
efficient when dimmed? And does dimming make a difference to their life?

In the early days of pocket calculators, the red LEDs they used were
pulsed in order to extend the battery life, so I can guess from that
much alone what the answer is.

That was generally a consequence to reducing the Chip IO to drive the
LEDs in a matrix scheme with column and row multiplexing.
https://docs.broadcom.com/doc/AV02-3697EN

I was under the impression that pulsing an LED would increase heat and
lower efficiency, as the voltage across the LED would be higher during
the pulse, leading to greater heat.

Many LEDs lose efficiency at high currents. This is one discussion on
the effects:

https://electronics.stackexchange.co...ent-brightness