Relay contact ratings.

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.

--
Cheers,
James Arthur

 

[linnix]

On Dec 15, 9:45 am, dagmargoodb...@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.

Chest fridge is hard to locate stuffs. Even with upright fridge,
foods are often hidden and spoiled. Perhaps the upright fridge should
be compartmentalized with clear drawers, or even multiple doors, to
minimum cold lost.

 

On Dec 15, 12:58 pm, linnix <m...@linnix.info-for.us> wrote:

On Dec 15, 9:45 am, dagmargoodb...@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.

Chest fridge is hard to locate stuffs.  Even with upright fridge,
foods are often hidden and spoiled.  Perhaps the upright fridge should
be compartmentalized with clear drawers, or even multiple doors, to
minimum cold lost.

You could always just stand a chest freezer up sideways. Oh, wait...

<SCNR>

--
Cheers,
James Arthur

 

[David Eather]

On 15/12/2011 9:22 AM, Sylvia Else 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 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.

??????????????

You're in Australia or NZ?

Altronics or MicroZed in Australia


In NZ:

http://www.electroflash.co.nz/picaxe-products/

$4.80 NZ

http://www.sicom.co.nz/new-picaxe08m-microcontroller-xidp337359.html

$7.11 NZ

As for cable - it is one 9 pin "D" plug with TXD RXD and GND used. - the
other end is anything you want and one or two resistors to the PICAXE chip



--
We have failed to address the fundamental truth that endless growth is
impossible in a finite world.

 

[David Eather]

On 15/12/2011 9:22 AM, Sylvia Else 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 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.

North Island

http://www.surplustronics.co.nz/shop/product-AXE007M2.html
$4.30 NZ

How slow is the mail in NZ?


--
We have failed to address the fundamental truth that endless growth is
impossible in a finite world.

 

On Dec 15, 1:05 pm, Phil Hobbs
<pcdhSpamMeSensel...@electrooptical.net> wrote:

On 12/15/2011 12:45 PM, dagmargoodb...@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.

Touché! (choking back up my snack)

I once had a classic "avocado" fridge that used almost as much
electricity as Al Gore, papered with bumper stickers to improve it. I
should've tried foam.

--
Cheers,
James Arthur

 

[David Eather]

On 15/12/2011 10:17 AM, linnix wrote:

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

$7 more than what? The *highest* price I could find for the chip was
about $11 NZ - double that for postage and your still well ahead of a
PICKIT 3. (If you can claim to program a micro-controller in assembly
then don't you already have a programmer that "burns" a chip?)

There are suppliers of PICAXE on both the north and south islands of NZ
and if none of them are any good then they do post - which is what an RS
solution would be. The "programmer" for a PICAXE is *literally* one
resistor which limits current from the RS-232 port to to chip (the chip
will still program at logic levels if you have one of those USB-RS232
converter things).

"Programming" goes like this - You apply 2 to 5.5 volts to the PICAXE
chip. The inbuilt, combined bootstrap/interpreter automatically runs
and continuously monitors the "serial in" (program) pin. When a valid
signal appears the PICAXE writes the program to flash (and eeprom if you
used that too) and then starts running the program)

There are lots of good reasons not to use a PICAXE.

-Maybe you can't write a fridge temperature control program in just one
thousand line of code.

-Maybe it will take you more attempts than the 10000 times you can
reprogram the thing to get a "bang-bang" controller working.

-Maybe you need more than 28 general purpose byte variables, 256 bytes
of scratch pad RAM and 256 bytes of EEPROM to store the state of the
fridge control algorithm algorithm

-Maybe your algorithm needs more computation power than 8000 multiplies
or divisions per second and the chip isn't up to the job

-Maybe you need more than the 6 I/O pins (you could just use a bigger
PICAXE chip)

-Maybe you need more than 3 x 10 bit ADC's

-Maybe you don't like how the I2C software support allows you to read
temperature directly in one command but only from a Dallas DS18D20

-Maybe you just don't like the English or you pathologically hate any
language called "BASIC" even though it PICAXE BASIC borrows heavily from
bot Java and C++

Whatever it is might be valid, but "price" is a joke.

If anyone can't afford a 9 pin plug and a resistor I will send them one
and for Christmas I will even add a meter of 3 way cable and a plastic
cover for the plug.

 

[Michael A. Terrell]

linnix wrote:

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.

Not if that fuse turns into a flaming ball of plasma.


--
You can't have a sense of humor, if you have no sense.

 

[linnix]

On Dec 15, 12:19 pm, David Eather <eat...@tpg.com.au> wrote:

On 15/12/2011 10:17 AM, linnix wrote:









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/687275...acc

$7 more than what?

PICKIT 3 vs. PICKIT 2 is around $7 to $8 more.

The *highest* price I could find for the chip was
about $11 NZ - double that for postage and your still well ahead of a
PICKIT 3. (If you can claim to program a micro-controller in assembly
then don't you already have a programmer that "burns" a chip?)

That's what the PICKITs are for.

...
There are lots of good reasons not to use a PICAXE.

-Maybe you can't write a fridge temperature control program in just one
thousand line of code.

I don't think that would be a problem.

-Maybe it will take you more attempts than the 10000 times you can
reprogram the thing to get a "bang-bang" controller working.

Probably not.

-Maybe you need more than 28 general purpose byte variables, 256 bytes
of scratch pad RAM and 256 bytes of EEPROM to store the state of the
fridge control algorithm algorithm

Yes, definitely. We would need that much ram just for the stack. We
cannot use the PICAXE.

-Maybe your algorithm needs more computation power than 8000 multiplies
or divisions per second and the chip isn't up to the job

May be not, but faster chips are always better, if not too expensive.

-Maybe you need more than the 6 I/O pins (you could just use a bigger
PICAXE chip)

Yes, definitely. We would need 10 to 15 I/Os. We cannot use the
PICAXE.

-Maybe you need more than 3 x 10 bit ADC's

Yes, probably 4 to 6 ADCs. We cannot use the PICAXE.

-Maybe you don't like how the I2C software support allows you to read
temperature directly in one command but only from a Dallas DS18D20

Yes, we don't want to pay for DS18D20. 25 cents thermistors are good
enough. We cannot use the PICAXE.

-Maybe you just don't like the English or you pathologically hate any
language called "BASIC" even though it PICAXE BASIC borrows heavily from
bot Java and C++

Yes, I hate BASIC dialect of English. I only speak C.

Whatever it is might be valid, but "price" is a joke.

Price is never the issue with useless tools.

We cannot use the PICAXE for any single reason above. I think we have
more than one.

 

[linnix]

On Dec 15, 1:32 pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:

linnix wrote:

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.

   Not if that fuse turns into a flaming ball of plasma.

Properly rated fuse never does that.

 

[krw@att.bizzzzzzzzzzzz]

On Thu, 15 Dec 2011 13:05:21 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

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.

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.

 

[krw@att.bizzzzzzzzzzzz]

On Tue, 13 Dec 2011 22:41:52 -0600, Les Cargill <lcargill99@comcast.com>
wrote:

krw@att.bizzzzzzzzzzzz wrote:
On Tue, 13 Dec 2011 17:52:48 -0600, Les Cargill<lcargill99@comcast.com
wrote:

dagmargoodboat@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...

Eveb Apple gets better, and cheaper. Your point?


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.

 

[John Fields]

On Thu, 15 Dec 2011 13:46:46 -0800 (PST), linnix
<me@linnix.info-for.us> wrote:

Yes, I hate BASIC dialect of English.

---
Why would you hate BASIC and what do you mean by "dialect of English"?

Run through a good compiler, the object code of any programming
language should be the same.
---

I only speak C.

---
More's the pity.

--
JF

 

[John Fields]

On Thu, 15 Dec 2011 13:48:31 -0800 (PST), linnix
<me@linnix.info-for.us> wrote:

On Dec 15, 1:32 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
linnix wrote:

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.

   Not if that fuse turns into a flaming ball of plasma.


Properly rated fuse never does that.

---
So, when a fuse blows, there's no plasma bridging the gap?

--
JF

 

[linnix]

On Dec 13, 10:55 am, linnix <m...@linnix.info-for.us> wrote:

On Dec 13, 9:21 am, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:









linnix 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.

   Items made with the gray plastic for sprinklers isn't certified for
indoor use.  It is low pressure & low temperature rated and easy to
break.

Added CAE, where some embedded designer are.  We started with
defrosting the fridge, perhaps controlling the microwave, and piping
hot water through the fridge into the toilet.  This way, we can
defrost the fridge everytime we flush the toilet.  However, in case we
don't flush the toilet often enough, we need a PIC to monitor the
toilet as well.

We are going to need defrost cycle counters, duration timers, target
temperature, pipe temperature and toilet counters.  So, first thing is
to build the counters.  I've decided to build with 42 LEDs and 4 595
shift registers.  See:

http://173.224.223.62/pic32

This should do it:

while(1) // loop forever
{
temp_fridge = read_temp(0); // Fridge temperature
temp_exch_beg = read_temp(1); // Temp. at beginning of exchanger
temp_exch_end = read_temp(2); // Temp. at end of exchanger
temp_room = read_temp(3); // room temp.

if(temp_fridge < temp_target)
{
compressor(TRUE);
sleep(TIME_COMPRESSOR);
compressor(FALSE);

temp_delta = read_temp(2) - read_temp(1);

// push latest value on data stack
push_comp_temp(temp_delta);

// if heat exchanger temp. delta is decreased, time to defrost
differential_temp();

if(defrost(TRUE))
{
heater(TRUE);
sleep(TIME_HEATER);
heater(FALSE);
}
}

led_display(temp_fridge);
sleep(TIME_IDLE);
}

 

[linnix]

On Dec 15, 4:53 pm, John Fields <jfie...@austininstruments.com> wrote:

On Thu, 15 Dec 2011 13:48:31 -0800 (PST), linnix









m...@linnix.info-for.us> wrote:
On Dec 15, 1:32 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
linnix wrote:

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.

   Not if that fuse turns into a flaming ball of plasma.

Properly rated fuse never does that.

---
So, when a fuse blows, there's no plasma bridging the gap?

--
JF

Not outside the package,

 

[josephkk]

On Tue, 13 Dec 2011 16:32:31 -0800 (PST), mrstarbom@gmail.com wrote:

I get the feeling you choose to be simple when it suits you and abusive when it doesn't. Calling a person a prick does not actually strengthen your case. Nor does suggesting I'm obtuse or an idiot. It just reflects badly on you and the wonderful land of Oz.

Supply and demand isn't simple, not when governments and organizations legislate against it.

Rubbish. Life span may go down a few years from obesity etc but life
expectancy has (in Oz for example) increased by more than 10 years since
1975.

FYI Life expectancy does not predict how long people alive today will live.
http://www.aihw.gov.au/how-is-life-expectancy-calculated/

There is no need to get snakey. Why mention your children if you didn't want to discuss them? Many foolish notions are predicated on a supposed concern for future generations.

You brought the subtopic up first Mrs Tarbom.

No, but the low level of your logic and reasoning makes this thread
unworthy of anyone's time. SO I am finished with answering you.

Ah, so you're going to take your bat and ball and go home? Pity, but by all means go and do something worthwhile. : )

 

[David Eather]

On 16/12/2011 7:46 AM, linnix wrote:

On Dec 15, 12:19 pm, David Eather<eat...@tpg.com.au> wrote:
On 15/12/2011 10:17 AM, linnix wrote:









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/687275...acc

$7 more than what?

PICKIT 3 vs. PICKIT 2 is around $7 to $8 more.

Ah. Got you. And (IIRC) you are correct that a PICKIT 2 won't do PIC24.

My response was in regard to SE's aims for a fridge controller. I don't
know what your requirement was.

The *highest* price I could find for the chip was
about $11 NZ - double that for postage and your still well ahead of a
PICKIT 3. (If you can claim to program a micro-controller in assembly
then don't you already have a programmer that "burns" a chip?)

SE said in a post that she can program in assembler. I make the
assumption that she is talking about a micro-controller because that is
the context of the thread.

That's what the PICKITs are for.

Un-needed for SE if she use's a PICAXE

...
There are lots of good reasons not to use a PICAXE.

-Maybe you can't write a fridge temperature control program in just one
thousand line of code.

I don't think that would be a problem.


-Maybe it will take you more attempts than the 10000 times you can
reprogram the thing to get a "bang-bang" controller working.

Probably not.


-Maybe you need more than 28 general purpose byte variables, 256 bytes
of scratch pad RAM and 256 bytes of EEPROM to store the state of the
fridge control algorithm algorithm

Yes, definitely. We would need that much ram just for the stack. We
cannot use the PICAXE.

For a bang-bang controller of a domestic refrigerator (SE's case)?
PICAXE is in BASIC. What the user can access is for their exclusive use.
The system manges it own stack from separate RAM.

-Maybe your algorithm needs more computation power than 8000 multiplies
or divisions per second and the chip isn't up to the job

8000 operations is not enough for SE's case?

May be not, but faster chips are always better, if not too expensive.


-Maybe you need more than the 6 I/O pins (you could just use a bigger
PICAXE chip)

Yes, definitely. We would need 10 to 15 I/Os. We cannot use the
PICAXE.

Ah - You can't use PICAXE-08M2. Yo might be able to use PICAXE-20M2. You
could use PICAXE-28X2, PICAXE-40X2. They are starting to be expensive,
but for a one off, if you don't have a set of tools and a programmer
already at hand, still worth a look

-Maybe you need more than 3 x 10 bit ADC's

Yes, probably 4 to 6 ADCs. We cannot use the PICAXE.

You could use PICAXE-28X2, PICAXE-40X2.

-Maybe you don't like how the I2C software support allows you to read
temperature directly in one command but only from a Dallas DS18D20

Yes, we don't want to pay for DS18D20. 25 cents thermistors are good
enough. We cannot use the PICAXE.

The PICAXE also implements plain vanilla 10-bit ADC's. If you want to
use a thermistor or just about anything else you can interface to a
micro-controller you can. If your an absolute Scrooge and don't care
about absolute accuracy you could even use the readinternaltemp command;
the hardware for that is free!

-Maybe you just don't like the English or you pathologically hate any
language called "BASIC" even though it PICAXE BASIC borrows heavily from
bot Java and C++

Yes, I hate BASIC dialect of English. I only speak C.

Doesn't that make love letters to that special someone difficult to read?

Does it require many #PRAGMA's before you can link up?

-----------------------

One thing that amazes me is that BASIC is often blasted because it is
easy to produce unstructured code and has that horrible "GOTO"
statement. But C is a great language - you just have to put in lots of
effort to produce properly structured code and not use the built in
"Goto" command.

Mind you, I do have a bad attitude to C. In uni I mastered Fortran, 8080
(and Z80), 6502, Pascal (I faked my way through Pascal, it just wasn't
interesting to me and I couldn't run it at home - thank goodness
commenting and analysing the algorithms was important), FORTH and even
edlin! - very useful stuff, they didn't even tell us we could type in
our name as a command and be amazed and entertained by the resulting
chaos. In the last few weeks of the last programming class one of the
fellow students asked which language they should specialise in to get a
job and they were told "C"!!! (followed by loud expletives from the class)

---------------------------------

Whatever it is might be valid, but "price" is a joke.

Price is never the issue with useless tools.

This is a useful tool, particularly for one off's with simple
requirements. For someone already set up and experienced with another
processor maybe not so useful. It did seem that SE didn't have that
(since she mentioned buying a programmer)

We cannot use the PICAXE for any single reason above. I think we have
more than one.

 

[josephkk]

On Tue, 13 Dec 2011 22:41:52 -0600, Les Cargill <lcargill99@comcast.com>
wrote:

krw@att.bizzzzzzzzzzzz wrote:
On Tue, 13 Dec 2011 17:52:48 -0600, Les Cargill<lcargill99@comcast.com
wrote:

dagmargoodboat@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...

Eveb Apple gets better, and cheaper. Your point?


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.

?-)

 

Mrs Tarbomb, thank you.
Which topic?