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Thermometer - Today's Math Challenge

Stone cut face of outdoor thermometer has...

180° rotational degrees for 130°F temperature change.

Bimetal thermometer element has...

180° rotational degrees for 90°F temperature change.

Bimetal is 9-1/4 turns (labeled Truflex P675RTM2), inner diameter is

1/4", outer diameter is 1-1/16"

How many (partial) turns to remove from outer bimetal to match physical requirement with bimetal movement ?:-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

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| 1962 | I love to cook with wine Sometimes I even put it in the food

Reply to
Jim Thompson
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"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Still futzing with this?

Reply to
Martin Riddle

Of course! ASIC design is easy. Honey-do projects are difficult ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 I love to cook with wine     Sometimes I even put it in the food
Reply to
Jim Thompson

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

This doesn?t make sense. It s almost as if you need a longer spiral. What if you hold the spiral at 8.5 turn what temp chang do you get?

Cheers

Reply to
Martin Riddle

No. It currently swings further than desired.

That's the plan... pin spiral at progressive points, and test, until span is correct.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 I love to cook with wine     Sometimes I even put it in the food
Reply to
Jim Thompson

Hey, this is sci.ELECTRONICS.... here! no stone mason projects allowed!

I'll be glad to sing the praises of the AD590JH as an outdoor temperature sensor, mine has been running for 21 years, now, and the calibration is still very good. You do have to protect it with a glob of silicone sealer to keep condensation off the leads.

Jon

Reply to
Jon Elson

Got a little two coil shaft driver 1-7/8" diameter, 1/2" thick?

Maybe that would be a solution, IF such a driver could be found.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 I love to cook with wine     Sometimes I even put it in the food
Reply to
Jim Thompson

I can recall GM panel indicators that were dual coil, vector indicators, no springs.

Do they still exist?

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 I love to cook with wine     Sometimes I even put it in the food
Reply to
Jim Thompson

I believe so... I don't know of a specific source for them at the moment, but I've seen recent literature in a microcontroller design handbook which talks about ways to use a micro's PWM outputs to drive an indicator which uses two coils in 90-degree quadrature.

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
  I do _not_ wish to receive unsolicited commercial email, and I will
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Reply to
Dave Platt

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