Inductive Sensor - Revision history

Kienle at 15:43, 9 April 2020

2020-04-09T15:43:03Z

← Older revision		Revision as of 15:43, 9 April 2020
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	Ok, this one is actually easy to test. Out of all the 6 to 36V probes, none worked on 5V except the 8mm '''capacitive''' one. And even then, it was much less sensitive than on 12V and only triggered against metal parts, while with the higher supply voltage and a voltage divider on the output, it reliably also triggered against printed parts and had a larger trigger distance than on 5V.		Ok, this one is actually easy to test. Out of all the 6 to 36V probes, none worked on 5V except the 8mm '''capacitive''' one. And even then, it was much less sensitive than on 12V and only triggered against metal parts, while with the higher supply voltage and a voltage divider on the output, it reliably also triggered against printed parts and had a larger trigger distance than on 5V.

	==Voltage Divider==		==PNP: Voltage Divider==

	The "proper" approach seems to drive the sensor within the correct voltage range (6-36V) and to use a voltage divider circuit (eg., 15K and 10K for 12V) so that the pin that reads the sensor voltage gets no more than 5V (12 * 10/25 = 4.8). Schematics for 12V [https://reprapworld.com/documentation/proxsensor.pdf] [http://www.3d-proto.de/public/img/IndSensorSetup.png]		The "proper" approach seems to drive the (PNP) sensor within the correct voltage range (6-36V) and to use a voltage divider circuit (eg., 15K and 10K for 12V) so that the pin that reads the sensor voltage gets no more than 5V (12 * 10/25 = 4.8). Schematics for 12V [https://reprapworld.com/documentation/proxsensor.pdf] [http://www.3d-proto.de/public/img/IndSensorSetup.png]

	<html><img width="560" src="http://www.3d-proto.de/public/img/IndSensorSetup.png"></html>		<html><img width="560" src="http://www.3d-proto.de/public/img/IndSensorSetup.png"></html>

			==NPN: Two voltage sources (UNTESTED)==

			A PNP sensor (3 wires) takes
			* an input voltage that drives the sensor (any voltage between 6-36V). A typical setup would use 24V from the RAMPS board.
			* 5V thru a pull-up resistor (eg. 10K). A typical setup would use 5V from the Arduino.
			* common ground (for 5V and 6-36V)

			Schematic with 12V and 5V [https://forum.arduino.cc/index.php?topic=642404.0]

			<html><img width="560" src="https://forum.arduino.cc/index.php?action=dlattach;topic=642404.0;attach=329702"></html>

	=Links=		=Links=

Kienle at 15:14, 9 April 2020

2020-04-09T15:14:55Z

← Older revision		Revision as of 15:14, 9 April 2020
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	Ok, this one is actually easy to test. Out of all the 6 to 36V probes, none worked on 5V except the 8mm '''capacitive''' one. And even then, it was much less sensitive than on 12V and only triggered against metal parts, while with the higher supply voltage and a voltage divider on the output, it reliably also triggered against printed parts and had a larger trigger distance than on 5V.		Ok, this one is actually easy to test. Out of all the 6 to 36V probes, none worked on 5V except the 8mm '''capacitive''' one. And even then, it was much less sensitive than on 12V and only triggered against metal parts, while with the higher supply voltage and a voltage divider on the output, it reliably also triggered against printed parts and had a larger trigger distance than on 5V.

	The "proper" approach seems to drive the sensor within the correct voltage range (6-36V) and to use a voltage divider circuit (eg., 15K and 10K for 12V) so that the pin that reads the sensor voltage gets no more than 5V (12 * 10/25 = 4.8). ~~Schematic~~ [https://reprapworld.com/documentation/proxsensor.pdf]		==Voltage Divider==

			The "proper" approach seems to drive the sensor within the correct voltage range (6-36V) and to use a voltage divider circuit (eg., 15K and 10K for 12V) so that the pin that reads the sensor voltage gets no more than 5V (12 * 10/25 = 4.8). Schematics for 12V [https://reprapworld.com/documentation/proxsensor.pdf] [http://www.3d-proto.de/public/img/IndSensorSetup.png]

			<html><img width="560" src="http://www.3d-proto.de/public/img/IndSensorSetup.png"></html>

	=Links=		=Links=

Kienle at 13:40, 9 April 2020

2020-04-09T13:40:41Z

← Older revision		Revision as of 13:40, 9 April 2020
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	=Introduction=		=Introduction=
	Inductive sensors are used to sense the Z height on 3D printers. For Marlin with RAMPS - use one that ~~has a~~ 5V ~~output~~, as opposed to 12V, as RAMPS cannot handle 12V without using additional components.		Inductive sensors are used to sense the Z height on 3D printers. They detect metal[https://automation-insights.blog/2010/04/12/inductive-proximity-sensor-targets-material-does-matter/].

			For Marlin with RAMPS - use one that is driven with 5V, as opposed to 12V, as RAMPS cannot handle 12V without using additional components (voltage divider with two resistors).

	Part numbers look like LJ18A3-8-Z/BY-5V for the 2018 D3D with LCD screen - where we use the 8 mm distance sensing to facilitate the sensor not hitting the print bed.		Part numbers look like LJ18A3-8-Z/BY-5V for the 2018 D3D with LCD screen - where we use the 8 mm distance sensing to facilitate the sensor not hitting the print bed.
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	=Tom's Guide 2=		=Tom's Guide 2=
	*Comparison - essentially, all distance sensing ~~capacitive~~ sensors are quite good.		*Comparison - essentially, all distance sensing '''inductive''' sensors are quite good.

	<html><iframe width="560" height="315" src="https://www.youtube.com/embed/il9bNWn66BY" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></html>		<html><iframe width="560" height="315" src="https://www.youtube.com/embed/il9bNWn66BY" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></html>
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	=5V vs. 6-36V=		=5V vs. 6-36V=

	As already mentioned, pick the 5V version of the sensor if it is available to you. The 6-36V version can be a drop-in replacement by powering it with 5V~~, but only if you have a sensor with 8mm distance sensing~~. However, the sensor will be less sensitive ~~[https://toms3d~~.~~org/2017/03/02/autoleveling-3d-~~printers~~-9-myths-12-sensors-tested/~~]:		As already mentioned, pick the 5V version of the sensor if it is available to you. The 6-36V version can be a drop-in replacement by powering it with 5V. However, the sensor will be less sensitive. This approach has been tested to work with printers built in Ghent at [[January 2020 STEAM Camp]].

			However, there is one source that has done extensive testing and claims that driving 6-36V versions of sensors with 5V only succeeded for an 8mm-distance '''capacitative''' sensor, so no inductive sensor worked out [https://toms3d.org/2017/03/02/autoleveling-3d-printers-9-myths-12-sensors-tested/]:
	#2 You can just run a standard 6 to 36V probe from 5V		#2 You can just run a standard 6 to 36V probe from 5V
	Ok, this one is actually easy to test. Out of all the 6 to 36V probes, none worked on 5V except the 8mm capacitive one. And even then, it was much less sensitive than on 12V and only triggered against metal parts, while with the higher supply voltage and a voltage divider on the output, it reliably also triggered against printed parts and had a larger trigger distance than on 5V.		Ok, this one is actually easy to test. Out of all the 6 to 36V probes, none worked on 5V except the 8mm '''capacitive''' one. And even then, it was much less sensitive than on 12V and only triggered against metal parts, while with the higher supply voltage and a voltage divider on the output, it reliably also triggered against printed parts and had a larger trigger distance than on 5V.

	~~This approach has been tested with printers built in Ghent at [[January 2020 STEAM Camp]]~~.

	The "proper" approach is to drive the sensor within the correct voltage range (6-36V) and to use a voltage divider circuit (eg., 15K and 10K for 12V) so that the pin that reads the sensor voltage gets no more than 5V (12 * 10/25 = 4.8). Schematic [https://reprapworld.com/documentation/proxsensor.pdf]		The "proper" approach seems to drive the sensor within the correct voltage range (6-36V) and to use a voltage divider circuit (eg., 15K and 10K for 12V) so that the pin that reads the sensor voltage gets no more than 5V (12 * 10/25 = 4.8). Schematic [https://reprapworld.com/documentation/proxsensor.pdf]

	=Links=		=Links=

Kienle at 12:58, 9 April 2020

2020-04-09T12:58:04Z

← Older revision		Revision as of 12:58, 9 April 2020
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	*5V is the critical part - 5V '''input''' - so can be powered from the RAMPS board directly		*5V is the critical part - 5V '''input''' - so can be powered from the RAMPS board directly
	*LJ18 - the 18 refers to the diameter of the sensor in mm (actually, M18 external threading)		*LJ18 - the 18 refers to the diameter of the sensor in mm (actually, M18 external threading)
	*-8- refers to the distance of sensing		*-8- refers to the distance of sensing in mm
	*Z/BY refers to normally open vs normally closed		*Z refers to DC (vs. AC)
			*/
			* B refers to normally open (vs. normally closed)
			* Y refers to PNP (vs. NPN)

	=Tom's Guide 1=		=Tom's Guide 1=
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	*See part numbers and what they mean at Aliexpress - [https://www.aliexpress.com/item/M18-8mm-sensing-DC-5V-PNP-NO-LJ18A3-8-Z-BY-5V-cylinder-inductive-proximity-sensor/32718397681.html]		*See part numbers and what they mean at Aliexpress - [https://www.aliexpress.com/item/M18-8mm-sensing-DC-5V-PNP-NO-LJ18A3-8-Z-BY-5V-cylinder-inductive-proximity-sensor/32718397681.html]

	The BX vs BY is NPN vs PNP ~~Detection~~ - ~~appears~~ wiring ~~will be~~ different		The BX vs. BY is NPN vs. PNP (both normally open) - wiring is different!

	How to wire LJ18A3-8-Z/BX~~-5V~~ vs Z/BY?		How to wire LJ18A3-8-Z/BX vs. Z/BY?

	=Notes=		=Notes=
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	This approach has been tested with printers built in Ghent at [[January 2020 STEAM Camp]].		This approach has been tested with printers built in Ghent at [[January 2020 STEAM Camp]].

			The "proper" approach is to drive the sensor within the correct voltage range (6-36V) and to use a voltage divider circuit (eg., 15K and 10K for 12V) so that the pin that reads the sensor voltage gets no more than 5V (12 * 10/25 = 4.8). Schematic [https://reprapworld.com/documentation/proxsensor.pdf]

	=Links=		=Links=

Kienle at 12:38, 9 April 2020

2020-04-09T12:38:54Z

← Older revision		Revision as of 12:38, 9 April 2020
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	<html><iframe width="560" height="315" src="https://www.youtube.com/embed/il9bNWn66BY" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></html>		<html><iframe width="560" height="315" src="https://www.youtube.com/embed/il9bNWn66BY" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></html>

			Transcript: https://toms3d.org/2017/03/02/autoleveling-3d-printers-9-myths-12-sensors-tested/

	=Samples=		=Samples=
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	*See [[D3D BOM]] for sourcing.		*See [[D3D BOM]] for sourcing.
	*See [[D3D Height Controller]] for design		*See [[D3D Height Controller]] for design

			=5V vs. 6-36V=

			As already mentioned, pick the 5V version of the sensor if it is available to you. The 6-36V version can be a drop-in replacement by powering it with 5V, but only if you have a sensor with 8mm distance sensing. However, the sensor will be less sensitive [https://toms3d.org/2017/03/02/autoleveling-3d-printers-9-myths-12-sensors-tested/]:

			#2 You can just run a standard 6 to 36V probe from 5V
			Ok, this one is actually easy to test. Out of all the 6 to 36V probes, none worked on 5V except the 8mm capacitive one. And even then, it was much less sensitive than on 12V and only triggered against metal parts, while with the higher supply voltage and a voltage divider on the output, it reliably also triggered against printed parts and had a larger trigger distance than on 5V.

			This approach has been tested with printers built in Ghent at [[January 2020 STEAM Camp]].

	=Links=		=Links=

Kienle at 12:06, 9 April 2020

2020-04-09T12:06:32Z

← Older revision		Revision as of 12:06, 9 April 2020
Line 9:		Line 9:

	*5V is the critical part - 5V '''input''' - so can be powered from the RAMPS board directly		*5V is the critical part - 5V '''input''' - so can be powered from the RAMPS board directly
	*LJ18 - the 18 refers to the diameter of the sensor in mm		*LJ18 - the 18 refers to the diameter of the sensor in mm (actually, M18 external threading)
	*-8- refers to the distance of sensing		*-8- refers to the distance of sensing
	*Z/BY refers to normally open vs normally closed		*Z/BY refers to normally open vs normally closed

Marcin: /* OSE Use Case */

2019-10-15T02:51:04Z

OSE Use Case

← Older revision		Revision as of 02:51, 15 October 2019
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	=OSE Use Case=		=OSE Use Case=
	*'''OSE currently uses the LJ18A3-8-Z/BY-5V sensor'''		*'''OSE currently uses the LJ18A3-8-Z/BY-5V sensor'''. Sourcing - [https://www.aliexpress.com/item/32718397681.html?spm=2114.search0104.3.2.5c786d64XyNwAB&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_204_10130_5727215_318_10547_10546_10059_10884_10548_5727315_10545_10887_10696_100031_10084_10083_10103_10618_452_10307_532,searchweb201603_60,ppcSwitch_0&algo_expid=3db8b377-2748-4424-801c-b2eba9d9e56d-0&algo_pvid=3db8b377-2748-4424-801c-b2eba9d9e56d&transAbTest=ae803_4&priceBeautifyAB=0]
	*This allows for a longer sensing distance, which is useful for larger machines (1 meter bed and larger)		*This allows for a longer sensing distance, which is useful for larger machines (1 meter bed and larger)

Marcin: /* Introduction */

2019-10-15T02:50:26Z

Introduction

← Older revision		Revision as of 02:50, 15 October 2019
Line 1:		Line 1:
			=OSE Use Case=
			*'''OSE currently uses the LJ18A3-8-Z/BY-5V sensor'''
			*This allows for a longer sensing distance, which is useful for larger machines (1 meter bed and larger)

	=Introduction=		=Introduction=
	Inductive sensors are used to sense the Z height on 3D printers. For Marlin with RAMPS - use one that has a 5V output, as opposed to 12V, as RAMPS cannot handle 12V without using additional components.		Inductive sensors are used to sense the Z height on 3D printers. For Marlin with RAMPS - use one that has a 5V output, as opposed to 12V, as RAMPS cannot handle 12V without using additional components.

Marcin: /* Notes */

2018-06-06T21:50:58Z

Notes

← Older revision		Revision as of 21:50, 6 June 2018
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	*See [[D3D BOM]] for sourcing.		*See [[D3D BOM]] for sourcing.
	*See [[D3D Height Controller]] for design		*See [[D3D Height Controller]] for design

			=Links=

Marcin: /* Samples */

2018-06-06T21:08:08Z

Samples

← Older revision		Revision as of 21:08, 6 June 2018
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	*Ouput Status: Normally Open		*Ouput Status: Normally Open
	*Part number: LJ18A3-8-Z/BX		*Part number: LJ18A3-8-Z/BX
			*See part numbers and what they mean at Aliexpress - [https://www.aliexpress.com/item/M18-8mm-sensing-DC-5V-PNP-NO-LJ18A3-8-Z-BY-5V-cylinder-inductive-proximity-sensor/32718397681.html]

	The BX vs BY is NPN vs PNP Detection - appears wiring will be different		The BX vs BY is NPN vs PNP Detection - appears wiring will be different