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1)What are the rating for these kind of presets? I need the maximum current they can withstand without any harm, (Imax). [data need for a 100k preset]
2)I'm hoping to use this kind of voltage divider method to set reference voltages to a voltage comparator circuit. Because ref voltage should be able to adjust. Is there any good method to set reference voltages rather than this?
Here's one you could use: -
The important parameters are shown in red
If you use the maximum power limit (0.2 W) and the resistance (100 k\$\Omega\$) you can calculate the maximum allowable voltage across the device: -
\$Power = \dfrac{Voltage^2}{Resistance}\$ therefore voltage = \$\sqrt{0.2\times 100k}\$ = 141V.
However, it says in the spec the voltage limit is 100 Vdc so, what current would flow into the 100 k\$\Omega\$ pot if this voltage were applied? Answer is 1 mA.
This tells you that you need to ensure you don't put more than 100 V across it and you won't get more than 1 mA and your power rating won't be exceeded.
Because the value of the pot is so high, it will never pass enough current to cause a problem with the wiper. This statement is made with the understanding that the wiper takes no current as per a comment made by the OP.
However, it's very important that if you have a circuit where the wiper does draw current, you keep it well within the boundaries stated in the data sheet.
I used pots like this one up to 7-9mA any higher than that tends to be damaging them.
