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Electronics => Projects, Designs, and Technical Stuff => Topic started by: ammjy on February 23, 2018, 06:34:28 pm

Title: wanna know torgue of this kind of potentiometers !
Post by: ammjy on February 23, 2018, 06:34:28 pm

Hello, guys ! ) always thanks you for help.

http://www.dwengo.org/sites/default/files/tutorials/potentiometer.jpg (http://www.dwengo.org/sites/default/files/tutorials/potentiometer.jpg)

i really want know torgue of this kind of potentiometer !

for example, bourns company potentiometer have torgue value in specifications.

but, i can't find about it for chinese cheap potentiometers !.

please, let me know !
Title: Re: wanna know torgue of this kind of potentiometers !
Post by: Benta on February 23, 2018, 07:23:15 pm
Quote
for example, bourns company potentiometer have torgue value in specifications.

but, i can't find about it for chinese cheap potentiometers !.

I'm really surprised! Cheap Chinese potentiometers are otherwise always supported by excellent data sheets.

[/sarcasm]
Title: Re: wanna know torgue of this kind of potentiometers !
Post by: frozenfrogz on February 23, 2018, 07:33:43 pm
I guess you are SOL unless being able to measure it yourself though variance might be very high for these cheap pots.
If actuating force is of great importance in your design, why not stick to quality parts that give you reliable figures to work with? If I remember correctly the rotational torque values that Bournes provides are also quite fuzzy and give you a kind of best case / worst case data.
Title: Re: wanna know torgue of this kind of potentiometers !
Post by: ammjy on February 23, 2018, 08:45:07 pm
Thanks Reply !

the problem is my cheap potentiometer don't have model number on the body... but, body is almost same with linked photo.
Title: Re: wanna know torgue of this kind of potentiometers !
Post by: ammjy on February 23, 2018, 08:48:42 pm
Thanks Reply !

i will buy Bourns potentiometer. but before buy, if i know torque of my potentiometer, i can understand which torque have which rotation resistance.

because, i should use potentiometer for sensing degree for my wings. so, for wing move it self, should use low torque.


my cheap potentiometer torque is little bit strong. so if i know torque of this, i can predict torque with values.
Title: Re: wanna know torgue of this kind of potentiometers !
Post by: janoc on February 23, 2018, 09:23:12 pm
Thanks Reply !

i will buy Bourns potentiometer. but before buy, if i know torque of my potentiometer, i can understand which torque have which rotation resistance.

because, i should use potentiometer for sensing degree for my wings. so, for wing move it self, should use low torque.


my cheap potentiometer torque is little bit strong. so if i know torque of this, i can predict torque with values.

Um, if your design depends on the mechanical resistance of the pot, you are doing it wrong, IMO. The resistance/force varies a lot even on good quality pots from the same series. Moreover, it will change over time as the pot wears, gets dirty, even with temperature (grease and any seals get stiffer when cold). Also pots are not great as position sensors if you want the system to be reliable.

You may want to reconsider your position sensing arrangement - e.g. an optical encoder + encoder disk could work a whole lot better than a pot. Or maybe even capacitive sensor could be used - depends on what exactly are you trying to do.
Title: Re: wanna know torgue of this kind of potentiometers !
Post by: ammjy on February 23, 2018, 09:35:30 pm
Thanks you, Mr. Janoc !

i really got your point !

yes... i agree to your advise...
Title: Re: wanna know torgue of this kind of potentiometers !
Post by: langwadt on February 23, 2018, 09:50:18 pm
Thanks Reply !

i will buy Bourns potentiometer. but before buy, if i know torque of my potentiometer, i can understand which torque have which rotation resistance.

because, i should use potentiometer for sensing degree for my wings. so, for wing move it self, should use low torque.


my cheap potentiometer torque is little bit strong. so if i know torque of this, i can predict torque with values.

Um, if your design depends on the mechanical resistance of the pot, you are doing it wrong, IMO. The resistance/force varies a lot even on good quality pots from the same series. Moreover, it will change over time as the pot wears, gets dirty, even with temperature (grease and any seals get stiffer when cold). Also pots are not great as position sensors if you want the system to be reliable.

You may want to reconsider your position sensing arrangement - e.g. an optical encoder + encoder disk could work a whole lot better than a pot. Or maybe even capacitive sensor could be used - depends on what exactly are you trying to do.

or https://www.digikey.com/en/product-highlight/a/akm-semi/ak7451-magnetic-angle-sensor (https://www.digikey.com/en/product-highlight/a/akm-semi/ak7451-magnetic-angle-sensor)
Title: Re: wanna know torgue of this kind of potentiometers !
Post by: ammjy on February 23, 2018, 09:56:27 pm
Thanks you reply, Mr. Lengwadt !