Relay contact ratings.

On Dec 13, 6:52 pm, Les Cargill <lcargil...@comcast.com> wrote:

dagmargoodb...@yahoo.com wrote:
On Dec 13, 6:23 am, keithr<ke...@nowhere.com.au>  wrote:
snip

I prefer competition, the same process that makes everything we do and
buy get constantly better, and cheaper.  E.g., computers.

Except for Apple...

I don't understand.

Are Apple computers not ever better, cheaper, and faster too? The
first Mac, with 128k of memory and a pokey MC68K--sold for $2,495 in
1984. Is the latest iPad not wireless, cheaper, faster, and better in
almost every conceivable way?

Apple charges more, but is not Apple just one competitor among many?
Have no other choices sprung up, each with different combinations of
price and features, to suit the infinitely diverse spectrum of
individual preferences and needs? Something for everyone?

Clearly, I don't understand the question.

--
Cheers,
James Arthur

 

[John Doe]

"Phil Allison" <phil_a tpg.com.au> wrote:

"Stupider than Anyone Else"


http://australia.rs-online.com/web/p/electromechanical-relays/1279550/

is typical, specifying in this case 300 W / 2500 VA.


** The 300W figure refers to DC switching - ie 10 amps at 30 volts.

The 2500VA figure refers to resistive loads and 250VAC power.

There is nothing about inductive load switching.

See the data sheet.

Fuckwit.

When did they let you out of the asylum, Philly?
Your absence was not taken for granted.
--

... Phil




Path: news.astraweb.com!border6.newsrouter.astraweb.com!news-xfer.nntp.sonic.net!feeder.erje.net!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From: "Phil Allison" <phil_a tpg.com.au
Newsgroups: aus.electronics,sci.electronics.design
Subject: Re: Relay contact ratings.
Date: Thu, 8 Dec 2011 18:07:58 +1100
Lines: 24
Message-ID: <9kb62pFh8eU1 mid.individual.net
References: <9kb522Fa0nU1 mid.individual.net
X-Trace: individual.net rxulH8rpDAkd8ebiQLYfdgkn3bsjaVkpblhRxTp2jcnB4nDQXe
Cancel-Lock: sha1:f3Ea3dmoqfiYhd3uZj/Fwgn2qNc=
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.2180
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350
X-RFC2646: Format=Flowed; Response

 

[Sylvia Else]

On 10/12/2011 9:28 PM, Sylvia Else wrote:

On 10/12/2011 10:14 AM, David Eather wrote:
On 9/12/2011 10:56 AM, Sylvia Else wrote:
On 9/12/2011 4:23 AM, linnix wrote:
On Dec 8, 9:01 am, Fred Bloggs<bloggs.fredbloggs.f...@gmail.com
wrote:
On Dec 8, 1:50 am, Sylvia Else<syl...@not.here.invalid> wrote:









The defrost timer in my fridge is failing, and given the cost of a
'genuine' replacement part, I was pondering the option of making
electronic timer driving an electromechanical relay.

It probably won't happen, but when I was looking at relay specs, I
found
that their ratings are usually specified as a highish reactive power,
and a much lower real power.

http://australia.rs-online.com/web/p/electromechanical-relays/1279550/


is typical, specifying in this case 300 W / 2500 VA.

I find this difficult to fathom. Imagine a purely inductive 2500VA
load.
So no real power being switched, but it would arc like crazy. What
am I
missing here?

Sylvia.

There are aftermarket universals better than the OEM
parthttp://compare.ebay.com/like/290638915750?var=lv<yp=AllFixedPriceIt...




There are plenty of relays you can salvage out of garage opener (12V),
microwave (12V) or furnace (24V). Add a micro or 555 for less than $5
and you are done. I am doing one for my furnace timer.


Not sure about getting a 555 to run at 1 cycle per six hours.

A PIC would no doubt do the job easily, but then I'd have to invest in
hardware to program it.

Sylvia.

Sylvia,

Try a PICAXE 08M2 - it costs $2.50 in one off's and programs in BASIC.
Software and examples are free from www.picaxe.co.uk
It is not uncommon for people totally new to the PICAXE have had them
running programs within 30 minutes of getting their first chip.

The only stuff you need to program one is a serial port (RS232 or TTL
level) and a resistor.


Interesting. Thanks.

Though on further examination, by the time you've paid the higher cost

for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

 

[John Fields]

On Thu, 15 Dec 2011 10:22:50 +1100, Sylvia Else
<sylvia@not.here.invalid> wrote:>>

Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

---
Did you see my posts re. a hardware solution here and on abse?

--
JF

 

[John Fields]

On Tue, 13 Dec 2011 17:44:46 -0600, John Fields
<jfields@austininstruments.com> wrote:

On Tue, 13 Dec 2011 16:02:47 -0600, John Fields
jfields@austininstruments.com> wrote:

On Tue, 13 Dec 2011 12:52:04 -0600, John Fields
jfields@austininstruments.com> wrote:


---
View with a fixed-pitch font.

This will give a 30 minute defrost cycle following a 6 hour freezing
period:

---
Oops...
Please ignore; I'm fixing the error.

---
Done.

news/t4nfe7d1lnj35s2a3thchv3diqc827gq3g@4ax.com

---
Oops again:

news:t4nfe7d1lnj35s2a3thchv3diqc827gq3g@4ax.com

--
JF

 

[Sylvia Else]

On 15/12/2011 11:42 AM, John Fields wrote:

On Thu, 15 Dec 2011 10:22:50 +1100, Sylvia Else
sylvia@not.here.invalid> wrote:
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

---
Did you see my posts re. a hardware solution here and on abse?

I did, but I've formed the view that if I were going to do this, I'd
include the thermostat as well, and choose a better point in the
thermostat hysteresis at which to start the defrost cycle, rather than
having a random relationship as is the situation now.

Sylvia.

 

[linnix]

On Dec 14, 3:22 pm, Sylvia Else <syl...@not.here.invalid> wrote:

On 10/12/2011 9:28 PM, Sylvia Else wrote:







On 10/12/2011 10:14 AM, David Eather wrote:
On 9/12/2011 10:56 AM, Sylvia Else wrote:
On 9/12/2011 4:23 AM, linnix wrote:
On Dec 8, 9:01 am, Fred Bloggs<bloggs.fredbloggs.f...@gmail.com
wrote:
On Dec 8, 1:50 am, Sylvia Else<syl...@not.here.invalid> wrote:

The defrost timer in my fridge is failing, and given the cost of a
'genuine' replacement part, I was pondering the option of making
electronic timer driving an electromechanical relay.

It probably won't happen, but when I was looking at relay specs, I
found
that their ratings are usually specified as a highish reactive power,
and a much lower real power.

http://australia.rs-online.com/web/p/electromechanical-relays/1279550/

is typical, specifying in this case 300 W / 2500 VA.

I find this difficult to fathom. Imagine a purely inductive 2500VA
load.
So no real power being switched, but it would arc like crazy. What
am I
missing here?

Sylvia.

There are aftermarket universals better than the OEM
parthttp://compare.ebay.com/like/290638915750?var=lv<yp=AllFixedPriceIt...

There are plenty of relays you can salvage out of garage opener (12V),
microwave (12V) or furnace (24V). Add a micro or 555 for less than $5
and you are done. I am doing one for my furnace timer.

Not sure about getting a 555 to run at 1 cycle per six hours.

A PIC would no doubt do the job easily, but then I'd have to invest in
hardware to program it.

Sylvia.

Sylvia,

Try a PICAXE 08M2 - it costs $2.50 in one off's and programs in BASIC.
Software and examples are free fromwww.picaxe.co.uk
It is not uncommon for people totally new to the PICAXE have had them
running programs within 30 minutes of getting their first chip.

The only stuff you need to program one is a serial port (RS232 or TTL
level) and a resistor.

Interesting. Thanks.

Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

Get the PICKIT 3 for $7 more, in case you want to program PIC24 or
PIC32. Not sure if PICKIT 2 can program them.

http://australia.rs-online.com/web/p/microcontroller-processor/6872750/?origin=PSF_392815|acc

 

[John Fields]

On Wed, 14 Dec 2011 18:52:36 -0600, John Fields
<jfields@austininstruments.com> wrote:

On Tue, 13 Dec 2011 17:44:46 -0600, John Fields
jfields@austininstruments.com> wrote:

On Tue, 13 Dec 2011 16:02:47 -0600, John Fields
jfields@austininstruments.com> wrote:

On Tue, 13 Dec 2011 12:52:04 -0600, John Fields
jfields@austininstruments.com> wrote:


---
View with a fixed-pitch font.

This will give a 30 minute defrost cycle following a 6 hour freezing
period:

---
Oops...
Please ignore; I'm fixing the error.

---
Done.

news/t4nfe7d1lnj35s2a3thchv3diqc827gq3g@4ax.com

---
Oops again:

news:t4nfe7d1lnj35s2a3thchv3diqc827gq3g@4ax.com

---
And, for the ASCIImatic (thanks, Steve :

.. +V
.. |
.. 4060 Vcc +----+
.. +------+ | U3C |K | O---->C
.. +-887K--|Rs MR|-------|------+-A / DIODE COIL]- -|K1
.. | | | | | Y-+ | | O-> |<-O->NC
.. +-442K--|Rt | 10k +-B | +----+ |
.. | | | | | | | +-------->NO
.. +-0.1ľF-|Ct Q13|--10nF-+ +-A | C
.. +------+ | | Y-+--1k--B 2N2222
.. U1 | +-B \ E
.. U3A +-A | U3D |
.. 4081 Y-+ GND
.. +-B |
.. | |
.. | B-+
.. +-Y U3B
.. | A-+
.. 4060 | |
.. +------+ | Vcc |
.. +-976k--|Rs MR|-------+ | |
.. | | | | |
.. +-527k--|Rt | 10k |
.. | | | | |
.. +-1.0ľF-|Ct Q13|--[10nF]--+---+
.. +------+
.. U2
--
JF

 

[linnix]

On Dec 14, 4:55 pm, Sylvia Else <syl...@not.here.invalid> wrote:

On 15/12/2011 11:42 AM, John Fields wrote:









On Thu, 15 Dec 2011 10:22:50 +1100, Sylvia Else
syl...@not.here.invalid>  wrote:
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

---
Did you see my posts re. a hardware solution here and on abse?

I did, but I've formed the view that if I were going to do this, I'd
include the thermostat as well, and choose a better point in the
thermostat hysteresis at which to start the defrost cycle, rather than
having a random relationship as is the situation now.

Yes, we should have a thermistor for the room temperature, one for the
inside temperature, one at the beginning of the heat exchanger and one
at the end. This way, we can measure the temperature gradient based
on compressor and heater run time, and control them. This should
reduce unnecessary heating and cooling cycles.

 

On Dec 14, 8:04 pm, linnix <m...@linnix.info-for.us> wrote:

On Dec 14, 4:55 pm, Sylvia Else <syl...@not.here.invalid> wrote:



On 15/12/2011 11:42 AM, John Fields wrote:

On Thu, 15 Dec 2011 10:22:50 +1100, Sylvia Else
syl...@not.here.invalid>  wrote:
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

---
Did you see my posts re. a hardware solution here and on abse?

I did, but I've formed the view that if I were going to do this, I'd
include the thermostat as well, and choose a better point in the
thermostat hysteresis at which to start the defrost cycle, rather than
having a random relationship as is the situation now.

Yes, we should have a thermistor for the room temperature, one for the
inside temperature, one at the beginning of the heat exchanger and one
at the end.  This way, we can measure the temperature gradient based
on compressor and heater run time, and control them.  This should
reduce unnecessary heating and cooling cycles.

The US Department of Energy sponsored research into improving
refrigerator efficiency. Here are a couple of starter links:
http://www.ornl.gov/info/ornlreview/rev28_2/text/fri.htm
http://www.ornl.gov/info/press_releases/get_press_release.cfm?ReleaseNumber=mr19970501-00

The main thing was increasing insulation from 1/2" to 2". Adaptive
defrost is mentioned too (in the 2nd link).

The ultimate in efficient refrigerators is a chest freezer, home-
converted into a fridge.
http://mtbest.net/chest_fridge.html

--
Cheers,
James Arthur

 

[linnix]

On Dec 14, 8:52 pm, dagmargoodb...@yahoo.com wrote:

On Dec 14, 8:04 pm, linnix <m...@linnix.info-for.us> wrote:









On Dec 14, 4:55 pm, Sylvia Else <syl...@not.here.invalid> wrote:

On 15/12/2011 11:42 AM, John Fields wrote:

On Thu, 15 Dec 2011 10:22:50 +1100, Sylvia Else
syl...@not.here.invalid>  wrote:
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

---
Did you see my posts re. a hardware solution here and on abse?

I did, but I've formed the view that if I were going to do this, I'd
include the thermostat as well, and choose a better point in the
thermostat hysteresis at which to start the defrost cycle, rather than
having a random relationship as is the situation now.

Yes, we should have a thermistor for the room temperature, one for the
inside temperature, one at the beginning of the heat exchanger and one
at the end.  This way, we can measure the temperature gradient based
on compressor and heater run time, and control them.  This should
reduce unnecessary heating and cooling cycles.

The US Department of Energy sponsored research into improving
refrigerator efficiency.  Here are a couple of starter links:http://www..ornl.gov/info/ornlreview/rev28_2/text/fri.htmhttp://www.ornl.gov/info/press_releases/get_press_release.cfm?Release...

The main thing was increasing insulation from 1/2" to 2".  Adaptive
defrost is mentioned too (in the 2nd link).

Yes, that's exactly what i am thinking about.

The ultimate in efficient refrigerators is a chest freezer, home-
converted into a fridge.http://mtbest.net/chest_fridge.html

Or a regular fridge turned sideway, with door pointing up.

 

On Dec 15, 12:35 am, linnix <m...@linnix.info-for.us> wrote:

On Dec 14, 8:52 pm, dagmargoodb...@yahoo.com wrote:



On Dec 14, 8:04 pm, linnix <m...@linnix.info-for.us> wrote:

On Dec 14, 4:55 pm, Sylvia Else <syl...@not.here.invalid> wrote:

On 15/12/2011 11:42 AM, John Fields wrote:

On Thu, 15 Dec 2011 10:22:50 +1100, Sylvia Else
syl...@not.here.invalid>  wrote:
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

---
Did you see my posts re. a hardware solution here and on abse?

I did, but I've formed the view that if I were going to do this, I'd
include the thermostat as well, and choose a better point in the
thermostat hysteresis at which to start the defrost cycle, rather than
having a random relationship as is the situation now.

Yes, we should have a thermistor for the room temperature, one for the
inside temperature, one at the beginning of the heat exchanger and one
at the end.  This way, we can measure the temperature gradient based
on compressor and heater run time, and control them.  This should
reduce unnecessary heating and cooling cycles.

The US Department of Energy sponsored research into improving
refrigerator efficiency.  Here are a couple of starter links:http://www.ornl.gov/info/ornlreview/rev28_2/text/fri.htmhttp://www.or......

The main thing was increasing insulation from 1/2" to 2".  Adaptive
defrost is mentioned too (in the 2nd link).

Yes, that's exactly what i am thinking about.



The ultimate in efficient refrigerators is a chest freezer, home-
converted into a fridge. http://mtbest.net/chest_fridge.html

Or a regular fridge turned sideway, with door pointing up.

The chest freezer works better--the insulation's thicker. I might do
one one day. Or not.

Turning an upright fridge sideways would be a lot more work--orienting
the coils, for one thing. You could just strap some 4" foam
insulation board on a standard fridge--that's damn ugly, but it's
green I think I just qualified for a green subsidy. Or a DOE
grant.

--
Cheers,
James Arthur

 

[Klaus Kragelund]

On 9 Dec., 17:55, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:

On Fri, 9 Dec 2011 08:29:56 -0800 (PST), linnix





m...@linnix.info-for.us> wrote:
On Dec 9, 7:47 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Fri, 09 Dec 2011 10:17:53 -0500, "Michael A. Terrell"

mike.terr...@earthlink.net> wrote:

Trevor Wilson wrote:

**IME, the vast majority of lightning problems occur via TV antennas.
Power line issues are massively over-stated. Again, the only time I can
pin point a power line "surge" as the direct cause of a problem was a
very long time ago, when a 5kV bearer fell across the 240VAC main
overhead lines. The damage was considerable and affected several blocks.

  You wouldn't say that if you ever see an outlet explode and blow a
hole in the wall, when lightning hit the power line a mile away.  I
have.  The noise was deafening, and scared the hell out of my
grandparents & parents.  It took out all the power on my grandparents
farm, as well.

We have underground utilities here.  Some years ago a lightning strike
at a substation 4 miles away blew out numerous appliances, several
PC's, a TV set, and every light dimmer in the house.

I also have dead microwave and furnace transformers.  After installing
MOVs and FUSEs on the primary, i only have to replace them rather than
transformers.  OEM transformers are ridiculously expensive too.

After my event, I installed a full-phase MOV block at the entry
cabinet.

Be carefull about using MOVs. It wears out over time, from subjected
surges. So when your are not home, it may blow without your knowledge,
and the next time you have a lightning surge it doesn't protect at
all. Better to use Transient Voltage Suppressor, Tranzorbs....

Cheers

Klaus

 

[Jasen Betts]

On 2011-12-13, Sylvia Else <sylvia@not.here.invalid> wrote:

the closer the inside temperature of the fridge is to the outside
temperatue the less work the compressor needs to do to circulate he
coolant.

a warm evaporator means the compressor's input is at a higner pressure
than normal and thus it needs to do less work to compress the gas
enough to condense in the condenser,

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".

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[Jasen Betts]

On 2011-12-13, linnix <me@linnix.info-for.us> wrote:

If you were defrosting by a heater something like a heatsink or
radiator that was being refrigerated to cool it, but was operating  in
open air and not in a closed cabinet, it would be slightly more
beneficial from a power saving viewpoint to let the defrost heater's
heat dissipate first before re-starting the compressor.

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?

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[Jasen Betts]

On 2011-12-13, John Fields <jfields@austininstruments.com> wrote:

. 4060
. +------+
. +-976K--|Rs MR|-----
. | | |
. +-527K--|Rt |
. | | |
. +-1.0ÂľF-|Ct Q13|-100n
. +------+

. 4060
. +------+
. +-887k--|Rs MR|-----
. | | |
. +-442k--|Rt |
. | | |
. +-0.1ÂľF-|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|-----|<---+ +-->|--+
| | | | |
+-1.0ÂľF-|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|-----|<---+ +-->|--+
| | | | |
+-1.0ÂľF-|Ct Q14|--+--|<---+ |
+------+ | |/
+---3K3----------| BC547
|\|
\
--- 0V


--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[Phil Hobbs]

On 12/15/2011 1:35 AM, dagmargoodboat@yahoo.com wrote:

On Dec 15, 12:35 am, linnix<m...@linnix.info-for.us> wrote:
On Dec 14, 8:52 pm, dagmargoodb...@yahoo.com wrote:



On Dec 14, 8:04 pm, linnix<m...@linnix.info-for.us> wrote:

On Dec 14, 4:55 pm, Sylvia Else<syl...@not.here.invalid> wrote:

On 15/12/2011 11:42 AM, John Fields wrote:

On Thu, 15 Dec 2011 10:22:50 +1100, Sylvia Else
syl...@not.here.invalid> wrote:
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.

http://australia.rs-online.com/web/p/microcontroller-processor/0381582/

PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.

Sylvia.

---
Did you see my posts re. a hardware solution here and on abse?

I did, but I've formed the view that if I were going to do this, I'd
include the thermostat as well, and choose a better point in the
thermostat hysteresis at which to start the defrost cycle, rather than
having a random relationship as is the situation now.

Yes, we should have a thermistor for the room temperature, one for the
inside temperature, one at the beginning of the heat exchanger and one
at the end. This way, we can measure the temperature gradient based
on compressor and heater run time, and control them. This should
reduce unnecessary heating and cooling cycles.

The US Department of Energy sponsored research into improving
refrigerator efficiency. Here are a couple of starter links:http://www.ornl.gov/info/ornlreview/rev28_2/text/fri.htmhttp://www.or......

The main thing was increasing insulation from 1/2" to 2". Adaptive
defrost is mentioned too (in the 2nd link).

Yes, that's exactly what i am thinking about.



The ultimate in efficient refrigerators is a chest freezer, home-
converted into a fridge. http://mtbest.net/chest_fridge.html

Or a regular fridge turned sideway, with door pointing up.

The chest freezer works better--the insulation's thicker. I might do
one one day. Or not.

Turning an upright fridge sideways would be a lot more work--orienting
the coils, for one thing. You could just strap some 4" foam
insulation board on a standard fridge--that's damn ugly, but it's
green I think I just qualified for a green subsidy. Or a DOE
grant.

--
Cheers,
James Arthur

Refrigeration systems generally rely on gravity to avoid trying to
compress liquid, which is somewhat more difficult to do. Running one on
its side is not guaranteed to work.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[linnix]

On Dec 15, 1:47 am, Klaus Kragelund <klausk...@hotmail.com> wrote:

On 9 Dec., 17:55, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-









Web-Site.com> wrote:
On Fri, 9 Dec 2011 08:29:56 -0800 (PST), linnix

m...@linnix.info-for.us> wrote:
On Dec 9, 7:47 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Fri, 09 Dec 2011 10:17:53 -0500, "Michael A. Terrell"

mike.terr...@earthlink.net> wrote:

Trevor Wilson wrote:

**IME, the vast majority of lightning problems occur via TV antennas.
Power line issues are massively over-stated. Again, the only time I can
pin point a power line "surge" as the direct cause of a problem was a
very long time ago, when a 5kV bearer fell across the 240VAC main
overhead lines. The damage was considerable and affected several blocks.

  You wouldn't say that if you ever see an outlet explode and blow a
hole in the wall, when lightning hit the power line a mile away.  I
have.  The noise was deafening, and scared the hell out of my
grandparents & parents.  It took out all the power on my grandparents
farm, as well.

We have underground utilities here.  Some years ago a lightning strike
at a substation 4 miles away blew out numerous appliances, several
PC's, a TV set, and every light dimmer in the house.

I also have dead microwave and furnace transformers.  After installing
MOVs and FUSEs on the primary, i only have to replace them rather than
transformers.  OEM transformers are ridiculously expensive too.

After my event, I installed a full-phase MOV block at the entry
cabinet.

Be carefull about using MOVs. It wears out over time, from subjected
surges. So when your are not home, it may blow without your knowledge,
and the next time you have a lightning surge it doesn't protect at
all. Better to use Transient Voltage Suppressor, Tranzorbs....

I always have a fuse with the MOV. If it blow (usually short out), it
will take out the fuse as well.

 

[linnix]

On Dec 15, 4:11 am, Jasen Betts <ja...@xnet.co.nz> wrote:

On 2011-12-13, linnix <m...@linnix.info-for.us> wrote:



If you were defrosting by a heater something like a heatsink or
radiator that was being refrigerated to cool it, but was operating  in
open air and not in a closed cabinet, it would be slightly more
beneficial from a power saving viewpoint to let the defrost heater's
heat dissipate first before re-starting the compressor.

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?

Good question. Perhaps i need a small NG heater instead.

 

[Phil Hobbs]

On 12/15/2011 12:45 PM, dagmargoodboat@yahoo.com wrote:

On Dec 15, 10:29 am, Phil Hobbs
pcdhSpamMeSensel...@electrooptical.net> wrote:
On 12/15/2011 1:35 AM, dagmargoodb...@yahoo.com wrote:
On Dec 15, 12:35 am, linnix<m...@linnix.info-for.us> wrote:
On Dec 14, 8:52 pm, dagmargoodb...@yahoo.com wrote:

The US Department of Energy sponsored research into improving
refrigerator efficiency. Here are a couple of starter links:http://www.ornl.gov/info/ornlreview/rev28_2/text/fri.htmhttp://www.or......

The main thing was increasing insulation from 1/2" to 2". Adaptive
defrost is mentioned too (in the 2nd link).

Yes, that's exactly what i am thinking about.

The ultimate in efficient refrigerators is a chest freezer, home-
converted into a fridge. http://mtbest.net/chest_fridge.html

Or a regular fridge turned sideway, with door pointing up.

The chest freezer works better--the insulation's thicker. I might do
one one day. Or not.

Turning an upright fridge sideways would be a lot more work--orienting
the coils, for one thing.

You could just strap some 4" foam
insulation board on a standard fridge--that's damn ugly, but it's
green I think I just qualified for a green subsidy. Or a DOE
grant.


Refrigeration systems generally rely on gravity to avoid trying to
compress liquid, which is somewhat more difficult to do. Running one on
its side is not guaranteed to work.

I think it's guaranteed not to work unless you rotate everything,
which is what I meant to insinuate. If convection-cooled, there's
also the problem of convection cooling not performing as designed --
it won't "draw."

More to the point, besides having to bend to the floor to get your
stuff, a sideways-refrigerator's contents (and cold air load) dumps
onto the floor every time you open the door. And, the contents would
be ready to spill, since all the shelves would be sideways too. You'd
have to put it on its back, which has even more problems.

The chest freezer's compressor is oversized for ultra-insulated
refrigerator service, but I suspect less oversized and a better and
more efficient match than a standard refrigerator's compressor.

So, the converted chest freezer wins on all fronts.

OTOH, 4 inches of judiciously applied pink foam beats most of these
problems, and it's extra-ugly.

If you stick it on a "harvest gold" refrigerator, it would be a big
improvement.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net