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schmitt trigger for temp control

so i want to control the temprature of a tec at 35C using a schmitt trigger, but all of the resources i found online are to complicated for me as i dont know anything about circutry. pls help. also, i want as low profile and lightweight as possible. also cr2032 battery powered. include tec, thermocouple and schmitt trigger materials

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Maybe i can do that in the next couple of days, but first things first, how do you want to power the tec? And what kind of tec is it?

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16 hours ago, Heats with Nvidia said:

Maybe i can do that in the next couple of days, but first things first, how do you want to power the tec? And what kind of tec is it?

powered by 2 cr2032 batteries, and i have no idea what kind of tec i need

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What do you want to accompllish with that TEC? Because i don't know a TEC that is so small and takes so little power that it can be powered by 2 cr2032 at all. Because a cr2032 has a little over 200mAh which times the 3V is roughly 0.6Wh. With two of them, thats 1.2Wh which is not a lot. The max current capacity oft a cr2032 is around 100mA with two, thats 200mA which is 600mW vor 0.6W which can be sustained for roughly an hour or two.

In short, it will eat batteries like nothing and accomplish next to nothing in the way.

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3 hours ago, Heats with Nvidia said:

What do you want to accompllish with that TEC? Because i don't know a TEC that is so small and takes so little power that it can be powered by 2 cr2032 at all. Because a cr2032 has a little over 200mAh which times the 3V is roughly 0.6Wh. With two of them, thats 1.2Wh which is not a lot. The max current capacity oft a cr2032 is around 100mA with two, thats 200mA which is 600mW vor 0.6W which can be sustained for roughly an hour or two.

In short, it will eat batteries like nothing and accomplish next to nothing in the way.

Basically it is a portable hand warmer that I’m making for a science project. Doesn’t have to be practical, just has to work as a proof of concept. The reason I'm not using something like a aaa battery is bc it had to be thin so that it can fit inside of a glove 

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Then you don't need any regulation at all all you can do with this amount of  power is slightly warm anyway. Its so little that the isolation provided by the glove its mounted in, will provide far more warmth than your TEC. Why don't you just use far more powerful batteries connected with a cable?

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42 minutes ago, Heats with Nvidia said:

Then you don't need any regulation at all all you can do with this amount of  power is slightly warm anyway. Its so little that the isolation provided by the glove its mounted in, will provide far more warmth than your TEC. Why don't you just use far more powerful batteries connected with a cable?

I never thought of that! That is a good idea. What type of batteries would you recommend? 

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I would just use a bunch of 18650ies with internal protection mounted a holder. You can charge those externally and carry spares with you. If you use four of them in series, you can use 12V tecs, which should be readily available. Also, these 18650 have a whole lot more punch. But please make sure they aren`t counterfit and have a proper protection circuit integrated, since you will have them in your clothes.

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19 hours ago, Heats with Nvidia said:

I would just use a bunch of 18650ies with internal protection mounted a holder. You can charge those externally and carry spares with you. If you use four of them in series, you can use 12V tecs, which should be readily available. Also, these 18650 have a whole lot more punch. But please make sure they aren`t counterfit and have a proper protection circuit integrated, since you will have them in your clothes.

what about the thermocouple and schmitt trigger? i have a basic understanding of how schmittt triggers work, but all of the thermocoules i can find are hundreds of dollars and look like replacements for a furnace. i can make a thermocouple, but i dont know what type to use

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21 hours ago, Idkwhattodowithmylife said:

just has to work as a proof of concept. The reason I'm not using something like a aaa battery is bc it had to be thin so that it can fit inside of a glove 

A demonstrator has to show that the idea works so just use AAA, battery bank or what ever and deliver digital design files for the "true" version with a slim battery that's safe. Todo so a.) do the math b.) present the datasheet/whitepaper claims of the battery c.) deliver the 3d-design files/drawings.

For the same reason just use an Arduino board or so (maybe a NodeMCU), mosfet board and temperature sensor. Again show that you can down size it solution.

 

 

Want another argument against CR2032? Run the math. One of my favourite quotes: You can't blow shit up with coin cells.

TL;DR they are low power and a TEC is somewhere around 5% efficiency. 

 

Latitude: 51.51313252247575 | Longitude: -0.21951026552290004

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2 hours ago, Idkwhattodowithmylife said:

what about the thermocouple and schmitt trigger? i have a basic understanding of how schmittt triggers work, but all of the thermocoules i can find are hundreds of dollars and look like replacements for a furnace. i can make a thermocouple, but i dont know what type to use

It doesn`t really matter what you use as a thermocouple, since there is not a lot of precision required in thos application. You can use an NTC or PTC. The most common ones are NTC thermistors. just choose one that is rated for that temperature range and not for 1000°C or something like that and that is in an enclosure that is easy to integrate into your glove.

 

By the way, where on this planet are you? Because that influences where to get your parts from and what parts are available.

Then you should have an idea what batteries to use and what TEC. Especially how to integrate that into a glove. Then we can talk about the electronics. If you have access to a lab power supply you can test the TEC with that, since you can regulate the temperature with the voltage. So you can make sure the concept is sound before you try to build the electronics.

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2 minutes ago, Heats with Nvidia said:

It doesn`t really matter what you use as a thermocouple, since there is not a lot of precision required in thos application. You can use an NTC or PTC. The most common ones are NTC thermistors. just choose one that is rated for that temperature range and not for 1000°C or something like that and that is in an enclosure that is easy to integrate into your glove.

 

By the way, where on this planet are you? Because that influences where to get your parts from and what parts are available.

Then you should have an idea what batteries to use and what TEC. Especially how to integrate that into a glove. Then we can talk about the electronics. If you have access to a lab power supply you can test the TEC with that, since you can regulate the temperature with the voltage. So you can make sure the concept is sound before you try to build the electronics.

i am located in canada. what is a lab psu

?

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13 minutes ago, Idkwhattodowithmylife said:

i am located in canada. what is a lab psu

?

A lab power supply. A power supply that has an adjustable output voltage. Since this is a science project, its most probably for school and i don`t know about canadian schools, but schools over here usually have those. As long as it can supply enough power and is in the correct voltage range, you can use one to test your tec and gloves without any regulation like a schmitt trigger or without the need to buy batteries at all. Just concentrate on one working glove with a tec on it and when that works, we can work on doing the rest. But i think this will be enough of a challenge to keep you busy for a while and even when you only finish this, you still have working, heated gloves. Also, then you can test, how much power is actually needed for these and calculate what type of battery would be good for this application. Also figuring out, where to place the tec, how to mount a heatsink and "heatsource" to it, distribute the heat into the glove etc... will be quite the challenge, since the tec usually is a hard, flat and square block and hands tend not to come in that form.

 

maybe its a better idea to just weave some heating wires into a normal glove that can be sandwiched between two others, then you don`t need a heatsink and you can heat all parts of the hand more evenly.

 

In hindsight, I will try to help you with the battery and regulation side of things, but when i continue to write about this glove, i do a lot of the work for you and thats just unfair to all the others doing science projects.

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4 hours ago, Heats with Nvidia said:

A lab power supply. A power supply that has an adjustable output voltage. Since this is a science project, its most probably for school and i don`t know about canadian schools, but schools over here usually have those. As long as it can supply enough power and is in the correct voltage range, you can use one to test your tec and gloves without any regulation like a schmitt trigger or without the need to buy batteries at all. Just concentrate on one working glove with a tec on it and when that works, we can work on doing the rest. But i think this will be enough of a challenge to keep you busy for a while and even when you only finish this, you still have working, heated gloves. Also, then you can test, how much power is actually needed for these and calculate what type of battery would be good for this application. Also figuring out, where to place the tec, how to mount a heatsink and "heatsource" to it, distribute the heat into the glove etc... will be quite the challenge, since the tec usually is a hard, flat and square block and hands tend not to come in that form.

 

maybe its a better idea to just weave some heating wires into a normal glove that can be sandwiched between two others, then you don`t need a heatsink and you can heat all parts of the hand more evenly.

 

In hindsight, I will try to help you with the battery and regulation side of things, but when i continue to write about this glove, i do a lot of the work for you and thats just unfair to all the others doing science projects.

Alr

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10 hours ago, Heats with Nvidia said:

maybe its a better idea to just weave some heating wires into a normal glove that can be sandwiched between two others

I presume this is about cooling: https://www.science.org/doi/10.1126/sciadv.aaw0536

or: https://www.nature.com/articles/s41467-019-09707-8

 

@Idkwhattodowithmylife if you need an idea how to present it (pictures and mockups): https://www.nature.com/articles/s41378-023-00583-3

Latitude: 51.51313252247575 | Longitude: -0.21951026552290004

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