Rotary Position Sensor - Revision history

Toaster at 23:10, 19 May 2020

2020-05-19T23:10:28Z

Gliderman: /* Potentiometer */ Add basic potentiometer information.

2020-05-19T00:02:42Z

Potentiometer: Add basic potentiometer information.

Gliderman at 23:01, 18 May 2020

2020-05-18T23:01:56Z

Gliderman at 22:58, 18 May 2020

2020-05-18T22:58:37Z

Gliderman at 21:28, 18 May 2020

2020-05-18T21:28:52Z

Gliderman: More headings

2020-05-18T21:26:40Z

More headings

Gliderman: Created page with "Rotary position sensors are used to track the rotational position of a shaft. This can be either absolute or relative position. =Encoder= Encoders typically output a digital..."

2020-05-18T20:17:22Z

Created page with "Rotary position sensors are used to track the rotational position of a shaft. This can be either absolute or relative position. =Encoder= Encoders typically output a digital..."

New page

Rotary position sensors are used to track the rotational position of a shaft. This can be either absolute or relative position.

=Encoder=

Encoders typically output a digital signal.

==Hall-effect==

Uses a magnet to detect the rotation of a shaft.

==Optical==

Similar to [[#Hall-effect|Hall-effect]] encoders, but using optics instead.

==Analog==

Produces a signal similar to a resolver. Also known as a sin-cos encoder.

=Resolver=

Can have multiple poles. Analog signal signal output.

@@ Line 1: / Line 1: @@
 Rotary position sensors are used to track the rotational position of a shaft. This can be either absolute or relative position.
-=Terms=
+==Terms==
-==Relative Position==
+===Relative Position===
-==Absolute Position==
+===Absolute Position===
-==Multi-turn==
+===Multi-turn===
-==Resolution==
+===Resolution===
-==Accuracy==
+===Accuracy===
-==Repeatability==
+===Repeatability===
-=Potentiometer=
+==Potentiometer==
 The inside of a potentiometer is a three terminal resistor. A resistive pad is connected between two terminals while a wiper connects between this pad and the last terminal. The wiper's position on the pad is controlled by the input shaft. As the wiper moves, the resistance measured from a pad terminal to the wiper terminal changes. In some applications, this resistance is directly used to control circuits. However, a potentiometer can be used as a controllable voltage divider by applying a voltage across the pad's terminals and measuring the voltage across a pad terminal to the wiper terminal. If the wiper terminal is connected to a load, the resultant output voltage can change, but for minimal loads this is typically negilible. There are limitations to the amount of power a potentiometer is capable of dissipating, so high power loads are typically not directly connected. Intermediate circuitry such as operational amplifiers or microcontrollers can take the output voltage and apply it to high power applications or convert to data for use elsewhere.
@@ Line 22: / Line 22: @@
 One issue with potentiometers is the output is not easily [[#Repeatability|repeatable]] and can easily be off by 10%[citation needed]. However, in applications where this is not a concern potentiometers make for a cheap way of rotary position measurement. A second issue stems from the mechanical connection between the pad and wiper. Over time, the wiper and pad will wear down which could affect the measurement of the potentiometer.
-==Linear Output==
+===Linear Output===
 To provide a consistent rate of change over the range of the potentiometer, a linearly resistive pad can be used. To achieve this, the pad is consistent throughout the range of the wiper, where the resistance across a one degree distance at any point on the pad is the same. Linear output potentiometers are commonly used for position measurement.
-==Logarithmic Output==
+===Logarithmic Output===
 In some specialized applications a logarithmic pad is used instead. Audio applications typically use logarithmic output potentiometers for volume control which matches how audio is heard by humans.
-=Encoder=
+==Encoder==
 Encoders typically output a digital signal.
-==Hall-effect==
+===Hall-effect===
 Uses a magnet to detect the rotation of a shaft.
-==Optical==
+===Optical===
 Similar to [[#Hall-effect|Hall-effect]] encoders, but using optics instead.
-===Transmissive===
+====Transmissive====
-===Reflective===
+====Reflective====
-==Analog==
+===Analog===
 Produces a signal similar to a resolver. Also known as a sin-cos encoder.
-==Capacitive==
+===Capacitive===
-==Inductive==
+===Inductive===
-=Resolver=
+==Resolver==
 Can have multiple poles. Analog signal signal output.
-=Linear Variable Differential Transformer=
+==Linear Variable Differential Transformer==
 Very similar to a resolver where a core moves in a field applied by primary coil. This is then transferred to two output coils where the amplitude of the signal changes based on the core's position.
-=Linear Variable Inductance Transducer=
+==Linear Variable Inductance Transducer==
 Operates by measuring the change in inductance as an iron core moves in and out of a coil.

@@ Line 16: / Line 16: @@
 =Potentiometer=
-==Linear==
+The ANSI electrical symbol is a resistor with an arrow pointing at the side, while the IEC electrical symbol is a box with an arrow pointing at the side. '''(TODO: Insert images of the symbols)'''
-==Logarithmic==
+One issue with potentiometers is the output is not easily [[#Repeatability|repeatable]] and can easily be off by 10%[citation needed]. However, in applications where this is not a concern potentiometers make for a cheap way of rotary position measurement. A second issue stems from the mechanical connection between the pad and wiper. Over time, the wiper and pad will wear down which could affect the measurement of the potentiometer.
 =Encoder=

← Older revision		Revision as of 23:01, 18 May 2020
Line 16:		Line 16:

	=Potentiometer=		=Potentiometer=
		+
		+	==Linear==
		+
		+	==Logarithmic==

	=Encoder=		=Encoder=

← Older revision		Revision as of 22:58, 18 May 2020
Line 44:		Line 44:

	Can have multiple poles. Analog signal signal output.		Can have multiple poles. Analog signal signal output.
		+
		+	=Linear Variable Differential Transformer=
		+
		+	Very similar to a resolver where a core moves in a field applied by primary coil. This is then transferred to two output coils where the amplitude of the signal changes based on the core's position.
		+
		+	=Linear Variable Inductance Transducer=
		+
		+	Operates by measuring the change in inductance as an iron core moves in and out of a coil.