Video

Capactive Proximity Switch

When connecting to power supply, RC oscillator does not work. When an object is clos eto capacitor electrode, the capacitor capacity will increase, and the oscillator will vibrate. Through the treatment of behind stage circuit, both signals of stop oscillation and oscillation will be converted to switch signs for checking the existence of object. this distance can be obtained, but to nonmetal object, the action distance is d etermined by material dielectric constant, the more dielectric constant, the more action distance will be obtained.

Working principle of Capactive Proximity Switch

Structural category	Object	Inductive surface	RC oscillator	Switching stage	Magnified output stage
Outward appearance illustration

Outward appearance illustration

The dielectric constants foe some important materials are as; osted as below;

Materials	Dielectric constant	Materials	Dielectric constant	Materials	Dielectric constant	Materials	Dielectric constant
Synthectic resin adhesive	3.6	Styrene	3	Alcohol	25.8	Polyvinyl	2 9
Mica	6	Prorcelain	4.4	Glass	5	Quartz glass	3 7
Ebonite	4	Petrolin	2.2	Cardboard	4.5	Silicon	2.8
Marble	8	Quartz sand	4.5	Cable rubber compound	2.5
Paper	2.3	Soft rubber	2.5	Gasoline	2.2
Organic glass	3.2	Water	80	Wood	2.7

Application illustration

Model				CM18	CM18
Product images
Dimension
Sense distance				0~3mm±10%	0~5mm±10%
Flush type	DC10~30VDC	NPN	NO	CM18-3003NA	CM18-3005NA
			NC	CM18-3003NB	CM18-3005NB
			NO+NC	CM18-3003NC	CM18-3005NC
		PNP	NO	CM18-3003PA	CM18-3005PA
			NC	CM18-3003PB	CM18-3005PB
			NO+NC	CM18-3003PC	CM18-3005PC
		Two-wire system	NO	CM18-3003LA	CM18-3005LA
		Two-wire system	NC	CM18-3003LB	CM18-3005LB
	AC90~250VAC		NO	CM18-2003A	CM18-2005A
			NC	CM18-2003B	CM18-2005B
			NO+NC	CM18-2003C	CM18-2005C
Sense distance				0~5mm±10%	0~8mm±10%
Non-flush type	DC10~30VDC	NPN	NO	CM18-3005NA	CM18-3008NA
			NC	CM18-3005NB	CM18-3008NB
			NO+NC	CM18-3005NC	CM18-3008NC
		PNP	NO	CM18-3005PA	CM18-3008PA
			NC	CM18-3005PB	CM18-3008PB
			NO+NC	CM18-3005PC	CM18-3008PC
		Two-wire system	NO	CM18-3005LA	CM18-3008LA
		Two-wire system	NC	CM18-3005LB	CM18-3008LB
	AC90~250VAC		NO	CM18-2005A	CM18-2008A
			NC	CM18-2005B	CM18-2008B
			NO+NC	CM18-2005C	CM18-2008C
Output current			DC	200mA
Output current			AC	300mA
Output voltage peak				Dc type below 3V, Ac type below 7V DC<3V, AC<7V
Consumption current				DC type 8mA at 12V, 15mA at 24V, AC below 10mA DC<15mA, AC<10mA
Standard detected object				Conductors and dielectric materials
Repeatability				0.02	0.02
Response frequency				DC50Hz/AC10Hz	DC50Hz/AC10Hz
Ambient temperature				-25℃-+75℃	-25℃-+75℃
Insulation resistance				50MΩ	50MΩ
Shell material				Metal	ABS Resin
Protection grade				IP54

CM18 IP67 NO+NC Capacitive Proximity Switch AC DC

Capactive Proximity Switch

Working principle of Capactive Proximity Switch

Outward appearance illustration

The dielectric constants foe some important materials are as; osted as below;

Application illustration