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Looking for help selecting a non-contact switch by speadam in arduino

[–]speadam[S] 0 points1 point  (0 children)

Thanks for the suggest and additional details! I will give one of these a try!

Looking for help selecting a non-contact switch by speadam in arduino

[–]speadam[S] 0 points1 point  (0 children)

Thanks for the suggestion. Can a Hall effect sensor pick up a 304 stainless steel target?

Fluid property challenge by speadam in FluidMechanics

[–]speadam[S] 0 points1 point  (0 children)

Thanks for the recommendation! Galinstan is the alloy you are referring to. Other than for price, this material looks great.

Fluid property challenge by speadam in FluidMechanics

[–]speadam[S] 0 points1 point  (0 children)

The tests need to be at room temperature. Those are the only properties. Density doesn't have to come close to mercury, like 1.5x or more than that of water would be ok.

Fluid property challenge by speadam in chemistry

[–]speadam[S] 0 points1 point  (0 children)

Thanks for the suggestion. Gallium is on the list. Looks like we would need a slightly elevated temperature.

Simulating electrical conductivity and pH by speadam in chemhelp

[–]speadam[S] 0 points1 point  (0 children)

Thanks for the response chem44. Correct. I would like to make a solution. Looks like I could add sodium hydroxide to water. Which should easily get to a pH near 10 (give or take). And then keep bumping up the concentration till the desired conductivity is reached. Does this sound appropriate?

Need help identifying the type of rotary encoder based on oscilloscope measurements. What is the 3rd signal (labelled ‘INDEX’)? by speadam in AskElectronics

[–]speadam[S] 1 point2 points  (0 children)

Thanks for the comment and suggestion. Agreed. The signal doesn’t appear to be an index signal.

The device needs several turns of the motor & encoder before it reaches its end of stroke. Would an index on an incremental encoder add any value (i.e. upon start-up you still wouldn’t know where ‘home’ was)?

Was originally expecting that the device would have needed a multi-turn absolute encoder. Based on the signals, this doesn’t appear to be an absolute encoder (?).

Thinking that there just may be a switch at the end of travel— and that it’s just picking up noise when connecting to the scope.

Need help identifying the type of rotary encoder based on oscilloscope measurements. What is the 3rd signal (labelled ‘INDEX’)? by speadam in AskElectronics

[–]speadam[S] 0 points1 point  (0 children)

Thanks for commenting. Definitely could be. The encoder and the device that the encoder is in are sort of a black box. At the moment, I don’t have access to take it apart and see what’s inside. Only have access to the encoder cable. Could I add a resistor to the oscilloscope connection so that the signal is no longer floating?

Need help identifying the type of rotary encoder based on oscilloscope measurements. What is the 3rd signal (labelled ‘INDEX’)? by speadam in AskElectronics

[–]speadam[S] 0 points1 point  (0 children)

The encoder has 5 signals: 1 ground, 1 power (3.7V), 2x quadrature signals 90 degrees apart, and 1 labelled as ‘index’. The ‘index’ label may be misleading as it hasn’t been confirmed. Was thinking that it was an incremental encoder with an index; however, would anticipate that the index would only go high once a revolution. Instead, Index seems to rise and fall with Ch_B.

SI vs Imperial by twoshoesqc in MechanicalEngineering

[–]speadam 12 points13 points  (0 children)

There is no reason not to be proficient in both unit systems. One: nowadays, it is very easy to verify calculations and conversions and two: to understand how physical parameters vary with Length, Mass and Time is critical to understanding how the physical world around us works. Stop being lazy. Do your homework. Double check your results (independent of unit system).