hair straightener Soldering hotplate

[capwizard]

Re: hair straightener Soldering hotplate

it took 1 minute

[capwizard]

Re: hair straightener Soldering hotplate

I tried COF bounding and I failed. I need tempered glass.

[capwizard]

Re: hair straightener Soldering hotplate

I tried COF bounding and I failed. I need tempered glass.

It is very difficult to accurately locate the cof precise position.

Help?

[capwizard]

Re: hair straightener Soldering hotplate

I tried with Kapton tape. Still failed because Kapton tape does not transfer heat.

But I succeeded, I shorted and welded ac wire to an adjustable wrench.

it is funny because the PTC limited ac current to 0.5 A and it welded ac wire to the wrench. ( I have 15A breaker on it, nothing happens, this did not trigger it.)

What I mean is can we use PTC characteristics as an adjustable current limiter for a super simple AC welding machine?

[budm]

Re: hair straightener Soldering hotplate

What is the cold resistance of that PTC @ 25c ? That will determine what spike current will be before the PTC resistance goes up.
Incandescent lamp is also has PTC.
http://lednique.com/technology-basics/bulb-basics/

[capwizard]

Re: hair straightener Soldering hotplate

This is a very good question, I have never thought of that.

first PTC is at 126.5 k ohms, heated for 3 sec. it changes to 51.9 k ohms if heated for 5 seconds it changed to 23 ohms! After 10 minutes PTC stayed at 3.2 ohms then I grabbed it with my hand, it changed to 27.6 k ohms. After 5 more minutes, it changes to 239.4 ohms.

This is the strangest thing I have ever seen. I mean...resistor. This PTC seems to be very sensitive to temperature.

diif... Can you confirm it with yours?

[sam_sam_sam]

Re: hair straightener Soldering hotplate

This is a very good question, I have never thought of that.

first PTC is at 126.5 k ohms, heated for 3 sec. it changes to 51.9 k ohms if heated for 5 seconds it changed to 23 ohms! After 10 minutes PTC stayed at 3.2 ohms then I grabbed it with my hand, it changed to 27.6 k ohms. After 5 more minutes, it changes to 239.4 ohms.

This is the strangest thing I have ever seen. I mean...resistor. This PTC seems to be very sensitive to temperature.

diif... Can you confirm it with yours?

Thank you for posting your results this will help me a lot

[capwizard]

Re: hair straightener Soldering hotplate

but-but-but my friend I don't even know what is happening?

29.1c now, PTC is at 298.3k ohms I just barely touched it with my hand and it changed to 91.5k ohms @ 29.5 c then I connect it to the electricity for 3 seconds it goes down to 5.0 ohms.

[sam_sam_sam]

Re: hair straightener Soldering hotplate

but-but-but my friend I don't even know what is happening?

Yes yes yes

You have given the information about the way these device behaves and that is a lot of useful information

29.1c now, PTC is at 298.3k ohms I just barely touched it with my hand and it changed to 91.5k ohms @ 29.5 c then I connect it to the electricity for 3 seconds it goes down to 5.0 ohms. 29.1c now, PTC is at 298.3k ohms I just barely touched it with my hand and it changed to 91.5k ohms @ 29.5 c then I connect it to the electricity for 3 seconds it goes down to 5.0 ohms.

I have to agree with you that this is very strange behavior for a device

I have one question for you what is the resistance of the device after it gets to operating temperature

As I have mentioned before I have a plan for using a couple of these heaters in a device I want to make so this is why I am very interested in your opservation of this device

This information is giving an insight of how I am going to control these devices

But I going to use the 12 or 24 volt version of these devices

When I have the time and after I finish a project that I working on I am going to buy a few of them but one of them I going to do a forensic autopsy even though the device has has not failed

But I going to go at it as though it has failed to see how it made and it might give me an insight into why it behaves the way it does

[budm]

Re: hair straightener Soldering hotplate

Your result shows the resistance goes down with an increase of temperature that will make it NTC, something is not right. Are yuu sure your meter is OK? Resistance to be in 100's of thousands of Ohms at room temp does not sounds right.
May be Diff can verify the results of his PTC.
You can find out what the resistance is by measuring Current and V drops then calculate the resistance.


If you cool the ceramics the resistance will
decrease and more power/energy will pass.

https://www.gmnameplate.com/company/...re-ptc-heaters

PTC heaters utilize Positive Temperature Coefficient materials i.e. materials that exhibit a positive resistance change in response to the increase in temperature. As the temperature increases, the electrical resistance of the material also increases, thus limiting the current flow. Simply put, the material allows current to pass when it’s cold, and restricts current to flow as the threshold temperature increases.

[gabiz_ro]

Re: hair straightener Soldering hotplate

Could be some NTC and PTC combined.
Don't remember mine if is 250 or 270 Celsius at 220V
But reading are
cold 3.58k
5 sec 0.7k increase quick
10 sec 218 ohm increase slowly
60 sec 244 ohms slowly decrease to 188 ohm then slowly increase to 260 ohms then fluctuate between 260-270 ohms and 0.35-0.4k few seconds later 0.6k and increasing (but during noted last sequence and check again was 0.45k and increasing)
To be more clear:
After disconnect
244 ohms and slowly decreasing until reach 188 ohms
Then slowly increased until 260 ohms
Then start to fluctuate
261 ohms 0.35 Kohms
264 ohms 0.38 Kohms
268 ohms 0.39 Kohms
270 ohms 0.4 Kohms
Then jump to 0.6 Kohms ind increasing slowly
Few seconds later when I check again was 0.45 Kohms and slowly increasing

[diif]

Re: hair straightener Soldering hotplate

0.8 k ohms on the one I've used and tested and 1.5 k ohms on my other.

[capwizard]

Re: hair straightener Soldering hotplate

Thank you Mr. diif

first things I did in the morning was to test this controversy PTC thermistor. Yes, First it shows 9.8 K ohms but when I squeeze it they change it to 534.6k and then after 10 minutes it changes back to 323.2K ohms

I think it’s very strange that when I am extruding this PTC which will change the resistance. So I opened one ptc to see what was happened and the result is two pieces of metal, they don't even touch each other? I think that's the reason why.

I have a question can we use this as a pressure sensor?

[sam_sam_sam]

Re: hair straightener Soldering hotplate

I have a question is the brown material conducive sandwich between the two metal plate and if that is case what is the resistance from one end of the brown material to the other end of it

[capwizard]

Re: hair straightener Soldering hotplate

no, the brown material is Kapton tape, they did not sandwich between with the metal plates, Kapton tape just warped two metal plates together.

how is it works I don't understand either?

[capwizard]

Re: hair straightener Soldering hotplate

no, the brown material is Kapton tape, they did not sandwich between with the metal plates, Kapton tape just warped two metal plates together.

2 metal plates ( i tested they are both very low ohms) loosely touched together. why they are not shorted together?

How is it works I don't understand either?

HELP!

[gabiz_ro]

Re: hair straightener Soldering hotplate

Post photo of wire to plate.
If wire go inside then isn’t connected to metal plate.
One may be PTC other NTC.
They are in thermal contact,one is heating the other,when temp reach threshold point current is limited

[capwizard]

Re: hair straightener Soldering hotplate

I couldn't sleep last night! so, I (picture 1,2,3) the PTC.

The result is, it was not a new technology. In the past, every household has one of PTC in their CRT TV degaussing circuit. (Picture 4, 5)

I need to apologize on the previous posts, I didn't know what that was, so, I threw the PTC away. I hope that I will not cause misleading errors.

I have a question can we use without an aluminum shell?

If I can get ( picture 5), then I can make and design my own PTC heating elements?

[budm]

Re: hair straightener Soldering hotplate

I couldn't sleep last night! so, I (picture 1,2,3) the PTC.

The result is, it was not a new technology. In the past, every household has one of PTC in their CRT TV degaussing circuit. (Picture 4, 5)

I need to apologize on the previous posts, I didn't know what that was, so, I threw the PTC away. I hope that I will not cause misleading errors.

I have a question can we use without an aluminum shell?

If I can get ( picture 5), then I can make and design my own PTC heating elements?

Well, thank you for the clarification, missing data is always the problem.

[capwizard]

Re: hair straightener Soldering hotplate

2 non-ferrous metal plates sandwiched with 3 non-ferrous, surface metal plating, PTC (back and front is 7.2 ohms, surface is low ohms) loosely touched together only wrapped loosely with Kapton tape.