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The temperature coefficient of resistors tends to be pretty low, compared to what (I understand) you are seeing, typically tens or hundreds of PPM (parts per million), but check the datasheet for your resistors to be sure. Consider using a constant current source to drive your LED, rather than a voltage source through a resistor. With only 100 ohms I ...


2

An old thread but just ran into it .. The issue of storing jump starters in car (where they should be stored frankly) seems to pose some risk as consumer reports state below. Unfortunately it is still very hard to find products with relevant storage temperatures. "All of the jump starters we tested had a maximum recommended operating/storage temperature,...


2

Two things I'd add to what's already been said in a couple of good answers: Even though the TLC27L2 says "rail-to-rail IO" on the front page of the datasheet, you should always look carefully at the specs to see what is meant by this claim. This chart from the datasheet shows that even though "rail-to-rail output" is claimed, you really ...


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Suspect the diodes first. Suspect the photodiode first. I don't think it's the LED, because I would expect the voltage across the LED to go down with increasing temperature, causing the current to go up. The leakage current in the photodiode is probably the culprit. Basically, as the temperature goes up, the photodiode will become more conductive. While ...


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The "Wemos D1 Mini" appears to be based on the ESP-8266. BTW, your voltage source is shown upside-down. The ESP-8266 ADC span is not very well controlled but it's approximately 1V. There is typically a divider - 220K in series with 100K on the input to accept approximately 3.2V F.S. The resistor + thermistor circuit is ideal (well, aside from self-...


1

The sensors appear to be pretty simple to hook up. I don't see a lot of room for getting things wrong in the example circuits. What I do notice is that the GY-906 DAA is in a metal can housing, and that the AliExpress modules show the housing sitting flush on the PCB. Since the traces are also on that side, I'd take a look and see in the housing has cut ...


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I don't think the output voltage changes much with supply voltage variations. For instance, look at this figure for the output voltage at 30 °C versus supply voltage change. I've added vertical lines for supplies of 2.7 volts and 3.3 volts: - BTW your schematic is incorrect: -


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On-die temperature and junction temperatures are similar, the difference being: On die temperature measurement is possible only if the device has a specific temperature diode sensor. On-die temperature is typically used by end use customers for various purposes - auto shutdown / power management / etc. Junction temperature, on the other hand, is an ...


1

Reading 4 wire RTDs with good/very good accuracy is not a trivial task. As previously mentioned, accurate current sources are needed to biasing the PT1000 resistances. VRef kind of sourcing can seem at first instance enough, but surely will not very accurate task. Not only possible VRef fluctuations, but also ADC side effects (input kick-backs etc.). Thus an ...


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