Maker Pro
Maker Pro

Relay contact ratings.

J

Jasen Betts

Jan 1, 1970
0
From context, I assume you meant "more" in that last sentence.

no, I means less.

It's a heat pump. and like a water pump, it uses less electricity
when pumping a smaller head.

14 degrees to 25 degrees is easier thant 4 degrees to 25 degrees.

it'll only take it a few seconds to get the temperature down to
freezing, but for a few seconds it's easier than normal.

if you let the defrosting heat escapes from the evaporator into the
contents of the fridge it's harder to call it back.
The question is - does it matter? That is, will running the compressor
when the element is warm do anything more than consume some extra
electricity.

Certainly nore "more".
 
J

Jasen Betts

Jan 1, 1970
0
Given that our natural gas is 80% cheaper than electricity, and going
lower. I might replumb the fridge with (gas) hot water pipes, with
electromechanical water valves. Can i use plastic sprinkler valves
for warm water? I can install the valves at the outlet, so they won't
be too hot anyway.

I'd look at using valves from/for a dishwasher or washing machine
they're designed for hot water and indoor appliances.

how are you planning on stopping the water from freezing?
 
J

Jasen Betts

Jan 1, 1970
0
. 4060
. +------+
. +-976K--|Rs MR|-----
. | | |
. +-527K--|Rt |
. | | |
. +-1.0µF-|Ct Q13|-100n
. +------+

. 4060
. +------+
. +-887k--|Rs MR|-----
. | | |
. +-442k--|Rt |
. | | |
. +-0.1µF-|Ct Q13|-[100
. +------+

976K?

887K?

1% tolerance parts where 20% tolerance would not measurably effect
the circuit?

I'd do it like this:


4060 +-----+--[100K]--+----------+-- +12
+------+ | | | |
+-3M3---|Rs MR|----+ | relay [/] |
| | | | coil | |
+-1M2---|Rt Q10|-----|<---+ +-->|--+
| | | | |
+-1.0µF-|Ct Q14|--+--|<---+ |
+------+ | |/
+---3K3----------| BC547
|\|
\
--- 0V

here the defrost time is 23m, 1/16 of
the cooling time which should be close to 6H (if I got my arithmetic right)

Add another diode between Q8 and MR to get 28m
(5/64) and another from Q6 to get even closer to 30m heating

4060
+------+
+-3M3---|Rs MR|----------+--[100k]--+------+--- +12
| | | | | |
| | Q6|-----|<---+ | |
| | | optional | relay[/] |
| | Q8|-----|<---+ coil | |
| | | | | |
+-1M2---|Rt Q10|-----|<---+ +-->|--+
| | | | |
+-1.0µF-|Ct Q14|--+--|<---+ |
+------+ | |/
+---3K3----------| BC547
|\|
\
--- 0V
 
If you stick it on a "harvest gold" refrigerator, it would be a big
improvement.

Harvest gold is a big step up from avocado. Our first house had an avocado
refrigerator and a harvest gold stove. All the houses in the subdivision were
decorated by the same blind contractor.
 
Apple has chosen not to compete on price, and have had
staggering profits.

So you don't have a point.
Much corporate medical care
in the US also does not compete on price, if at all.

Of course not. The government won't allow that to happen.
As a larger issue, when people drill
down into the details, competition as we generally
think of it rarely matters much - differences in
cost of orders of magnitude will matter while differences
of even as much as 2x will not.

Horseshit. Price isn't everything. Only one component of value is price.
But the more something is a commodity, especially
a commodity that has high volume, the more small
differences in price matter.

Volume has nothing to do with it.
Medical care is a craft good, and the farthest thing
there is from a commodity. Will that change? Probably.

It already has. Government will see that it continues.
Specific to medical care 1) we do not have competitive
provision of medical care in the US,

No, the government specifically won't allow it.
and 2) universal
care ala Yurp has actuarial effects very much
in favor of it.

Complete bullshit.
 
J

josephkk

Jan 1, 1970
0
Apple has chosen not to compete on price, and have had
staggering profits. Much corporate medical care
in the US also does not compete on price, if at all.


No, it is much more of a case of semi open (Wintel) and completely closed
(Mac) architectures.
As a larger issue, when people drill
down into the details, competition as we generally
think of it rarely matters much - differences in
cost of orders of magnitude will matter while differences
of even as much as 2x will not.
Maybe.

But the more something is a commodity, especially
a commodity that has high volume, the more small
differences in price matter.

Medical care is a craft good, and the farthest thing
there is from a commodity. Will that change? Probably.

Not at all, Medicare has already seen to that, it has been thoroughly
commoditized.
Specific to medical care 1) we do not have competitive
provision of medical care in the US, and 2) universal
care ala Yurp has actuarial effects very much
in favor of it.

Not by the track record.

?-)
 
S

Sylvia Else

Jan 1, 1970
0
no, I means less.

It's a heat pump. and like a water pump, it uses less electricity
when pumping a smaller head.

14 degrees to 25 degrees is easier thant 4 degrees to 25 degrees.

it'll only take it a few seconds to get the temperature down to
freezing, but for a few seconds it's easier than normal.

if you let the defrosting heat escapes from the evaporator into the
contents of the fridge it's harder to call it back.


Certainly nore "more".

Thing is, the compressor isn't going to say to itself "Oh, the incoming
gas is closer to ambient temperature, so reducing it by x degrees
requires less work.... I can relax for a bit then."

The compressor will run at its design power, and will generate a certain
amount of heat within itself, both as a result of the compressed gas
being warmer, and as a result of various inherent inefficiences. This
will raise its temperature. But if the incoming gas is warm, then that
will contribute to an even higher temperature in the compressor. There
is presumably a limit to how hot the compressor can run without damage,
and hence the question of whether it is safe to run it when the element
is warm.

Sylvia.
 
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