500*c capable Thermistor January 03, 2018 05:13AM |
Registered: 6 years ago Posts: 10 |
Re: 500*c capable Thermistor January 03, 2018 05:25AM |
Registered: 10 years ago Posts: 14,672 |
Re: 500*c capable Thermistor January 03, 2018 05:32AM |
Registered: 6 years ago Posts: 10 |
Re: 500*c capable Thermistor January 03, 2018 07:00AM |
Registered: 6 years ago Posts: 1,007 |
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Intensify
I think i read somewhere that some one had put a delay of 10 seconds of warmup time before checking the temperature wouldn't that overcome this problem of the low temperature reading?. I lost the link i have 3 windows open with 10+ tabs researching
[groups.google.com]
[groups.google.com]
Re: 500*c capable Thermistor January 03, 2018 06:56PM |
Registered: 6 years ago Posts: 10 |
Quote
MKSA
Quote
Intensify
I think i read somewhere that some one had put a delay of 10 seconds of warmup time before checking the temperature wouldn't that overcome this problem of the low temperature reading?. I lost the link i have 3 windows open with 10+ tabs researching
[groups.google.com]
[groups.google.com]
I think you should first learn about PID in addition to ADC, thermistor linearity (mainly lack of it)... !
I read about a 3D printer setting a house on fire. May be it was this guy ?
Re: 500*c capable Thermistor January 04, 2018 04:10AM |
Admin Registered: 16 years ago Posts: 13,886 |
Re: 500*c capable Thermistor January 04, 2018 02:32PM |
Registered: 10 years ago Posts: 14,672 |
Re: 500*c capable Thermistor January 05, 2018 03:27AM |
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Re: 500*c capable Thermistor January 05, 2018 09:53AM |
Registered: 10 years ago Posts: 14,672 |
Quote
MKSA
DC42, why not use a current source, take advantage of the 3 wires, in fact implement the same circuitry and measurement method normally used. PT100 which are common and cheap, could become the standard as there is a real need for higher extrusion temp.
Could be a selling point for the Duet ?
Re: 500*c capable Thermistor January 05, 2018 12:07PM |
Registered: 6 years ago Posts: 1,007 |
Quote
dc42
Quote
MKSA
DC42, why not use a current source, take advantage of the 3 wires, in fact implement the same circuitry and measurement method normally used. PT100 which are common and cheap, could become the standard as there is a real need for higher extrusion temp.
Could be a selling point for the Duet ?
Interesting idea. However, when using a PT1000 a fixed current source would have to be very accurate, would provide only a marginal improvement in resolution (less less than 2x), and would need to be disabled when using a thermistor.
It wouldn't help when using a PT100 because the main issue then is that the operating current needs to be kept low to avoid self-heating, which means you need an ADC that is accurate at reading small voltages. The MAX31865 chip we use on the daughter board is very good at this. If PT100 were to become standard equipment on 3D printers, we would include the MAX31865 on the Duet. But I think there may be a gradual move to PT1000 instead.
Re: 500*c capable Thermistor January 10, 2018 07:38PM |
Registered: 6 years ago Posts: 10 |
Does this work with the anet a8? Is there a guide?Quote
The latest release of RepRapFirmware supports PT1000 thermistors connected directly to thermistor inputs, see [duet3d.com]. It's not as good as a PT100 connected to the PT100 daughter board, because the resolution from reading the PT1000 that can be guaranteed is around 0.4C at room temperature, dropping to 0.8C at 400C. In fact we use 2-bit oversampling (to get 14 bits resolution from a 12 bit ADC) to increase the resolution of the displayed temperature to one quarter of these values. But I don't like to rely on oversampling because it assumes that noise in the reading is random, which it almost certainly isn't.
Re: 500*c capable Thermistor January 15, 2018 04:00PM |
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Re: 500*c capable Thermistor January 17, 2018 07:12AM |
Registered: 6 years ago Posts: 10 |
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hayedid
I have b3's pico hotend and 500C thermistor. It is a well designed unit.
Re: 500*c capable Thermistor September 27, 2020 01:45PM |
Registered: 4 years ago Posts: 13 |