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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

Reply to
dagmargoodboat
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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

Reply to
Klaus Kragelund

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".

--
?? 100% natural

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Reply to
Jasen Betts

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
Reply to
Jasen Betts

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|--+--|
Reply to
Jasen Betts

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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
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Reply to
Phil Hobbs

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

Reply to
linnix

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

Reply to
linnix

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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

Reply to
dagmargoodboat

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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.

Reply to
linnix

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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
 Click to see the full signature
Reply to
Phil Hobbs

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

-- Cheers, James Arthur

Reply to
dagmargoodboat

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Touch=E9! (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

Reply to
dagmargoodboat

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

You're in Australia or NZ?

Altronics or MicroZed in Australia

In NZ:

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$4.80 NZ

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$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.
Reply to
David Eather

North Island

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$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.
Reply to
David Eather

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$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.

Reply to
David Eather

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blocks.

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

--
You can't have a sense of humor, if you have no sense.
Reply to
Michael A. Terrell

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

That's what the PICKITs are for.

I don't think that would be a problem.

Probably not.

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

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

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

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

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

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

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.

Reply to
linnix

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Properly rated fuse never does that.

Reply to
linnix

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This should do it:

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

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

temp_delta =3D 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); }

Reply to
linnix

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