DIYbanter - View Single Post - Range clock

Don Klipstein

In article , wrote:
On Tue, 3 Jun 2008 13:03:28 +0000 (UTC), wrote:

In misc.consumers.frugal-living Jeff wrote:
wrote:
I think he is seriously over estimating the power usage of a
clock chip and LCD display. 1 Watt would be more like it.
5 Watts would be about right for an old mechanical stove clock.

You are, of course, neglecting the power supply losses. Non switching
regulators typically throw away half or more of the power. The trend is
away from them.

Well, we do seem to be arguing the number of angels dancing on pinheads.
;-)

Not really. Transformers draw significant power even when there is no
demand upon them. They just turn it into heat rather than work.

Plug in a wall wart with no load on it and measure the temperature and
current draw after an hour. That's a very tiny transformer.

If you remove one tube form a two tube florescent light fixture with
an old fashioned transformer, it hardly changes power consumption at
all.

On that last point, I find that the power consumption changes a lot.

The change is less when the ballast is one of those "pseudoparallel"
electronic ones rated to power more than one quantity of tubes, and the
remaining tube(s) get increased power when one tube is removed. But the
overall power consumption still goes down when one tube is removed.

- Don Klipstein )