Snap Action, Limit Switches

Part Number	Description / PDF	Quantity
51.801B Altech Corporation	FOOT SWITCH (3X)L1BK SPDTMOMSLDR	0
608.3000.207 Altech Corporation	LIMIT SWITCH IN65-SU1Z SM	0
51.709B Altech Corporation	FOOT SWITCHFM2SU1R(2X)F1BK SPDTM	0
618.6335.253 Altech Corporation	LIMIT SWITCHPLASTIC BODY I88-UV1	0
51.105R Altech Corporation	FOOT SWITCHFS1SU1STDCLR 1NO/1NCS	0
609.0148.025 Altech Corporation	LIMIT SWITCH WITH CABLE EEX-SU1Z	0
609.0145.007 Altech Corporation	LIMIT SWITCH WITH CABLE EEX-SU1Z	0
607.3201.051 Altech Corporation	ASI SWITCH ASI BI2 W D	0
51.216R Altech Corporation	FOOT SWITCHFS2SU1DSU1S(2X)STDCLR	0
606.1300.011 Altech Corporation	FOOTSWITCH WITHOUT COVER F1-SU1Z	9
608.5135.120 Altech Corporation	LIMIT SWITCH BI2-U1Z AH 270GR	0
614.1135.653 Altech Corporation	LIMIT SWITCHPLASTIC BODY D-U1Z A	0
51.204R Altech Corporation	FOOT SWITCHFS1U1RS(2X)STDCLR 1NO	0
51.664R Altech Corporation	FOOT SWITCHFM1SU1DSU1F1UBKREDGD	0
608.8171.016 Altech Corporation	LIMIT SWITCHPLASTIC BODY TI2-SU1	4
51.466R Altech Corporation	FOOT SWITCHFL1SU1DSU1SUSTDCLRGDA	0
601.9390.043 Altech Corporation	SWITCH SAFETY HINGE SHS3-U1Z-SA-	0
607.3200.058 Altech Corporation	SOLENOID LOCKING SWITCH ASI ASI	0
608.6117.017 Altech Corporation	LIMIT SWITCH I88-U1Z RIWK	20
607.3302.016 Altech Corporation	ASI SWITCH ASI I88 RIWK	0

Snap Action, Limit Switches

1. Overview

Snap-action switches and limit switches are critical electromechanical components that enable precise control of electrical circuits through mechanical motion. Snap-action switches feature a rapid-acting contact mechanism that ensures quick response to positional changes, while limit switches specifically detect the presence or absence of objects at predefined positions. These devices are fundamental in automation systems, safety circuits, and equipment interlocking, providing reliable feedback for process control and machine protection.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Standard Snap-Action Switch	Fast contact actuation, compact size, tactile feedback	Appliances, control panels
Heavy-Duty Limit Switch	Metal housing, high mechanical endurance	Industrial machinery, conveyor systems
Sealed Snap Switch	IP67-rated enclosure, resistant to dust/moisture	Outdoor equipment, washdown environments
Miniature Snap Switch	Sub-10mm dimensions, low operating force	Medical devices, IoT sensors

3. Structure and Components

Typical construction includes: - Actuator Mechanism: Lever, plunger, or roller assembly for motion detection - Contact System: Silver alloy contacts with snap-action spring for rapid switching - Housing: Thermoplastic (UL94 V-0) or metal enclosure with mounting features - Terminal Options: Quick-connect terminals, PCB pins, or screw terminals - Environmental Seals: Optional EPDM gaskets or molded-in sealing lips

4. Key Technical Parameters

Parameter	Typical Range	Importance
Rated Current	0.1-15A	Determines load capacity and contact lifespan
Operating Voltage	12-600VAC/DC	Affects insulation requirements and arcing resistance
Mechanical Life	10 -10 operations	Indicates durability under non-load conditions
Electrical Life	10 -10 operations	Measures contact longevity under rated load
Actuation Force	0.5-20N	Affects sensitivity and mechanical interface design
Response Time	1-10ms	Critical for high-speed automation applications

5. Application Fields

Industrial Automation: CNC machine tool positioning, robotic end-effectors
Building Systems: HVAC damper control, automatic door systems
Medical Equipment: Diagnostic analyzers, infusion pump occlusion detection
Consumer Electronics: Smart home devices, gaming console controllers
Transportation: Elevator door safety systems, railcar detection

6. Leading Manufacturers and Products

Manufacturer	Product Series	Key Features
Omron	D4MC Series	IP67 rating, 10 mechanical operations
TE Connectivity	Micro Switch TL Series	UL-certified, 15A rating
ABB	PLS Series	Adjustable actuator, explosion-proof design
OMRON	Z-15 Series	0.1A low-current switching capability

7. Selection Guidelines

Key considerations include: - Environmental conditions (temperature range, presence of contaminants) - Actuation force requirements vs. mechanical interface limitations - Contact configuration (SPDT/DPDT) and circuit requirements - Certification needs (UL, CSA, CE marks) - Mounting constraints (panel cutout dimensions) Example: For an automatic door system, specify a sealed IP65 switch with 10A/250VAC rating and lever actuator to ensure reliable operation in dusty environments.

8. Industry Trends

Current development directions include: - Integration with IoT systems through embedded sensing and wireless communication - Miniaturization for wearable and portable device applications - Enhanced material science for extended lifespan in harsh environments - Development of hybrid switches combining snap-action with proximity sensing - Increased focus on RoHS-compliant and recyclable materials - Smart diagnostics capabilities with condition monitoring sensors