Rotary Switches

Part Number	Description / PDF	Quantity
RM102772BCB C&K	SWITCH ROTARY 2POS 500MA 24V	611
MRK206-A NKK Switches	SWITCH ROTARY 2-6POS 0.4VA 28V	2272961
C7D0212S-30 Electroswitch	SWITCH ROTARY 12POS 500MA 125V	0
MRK403-A NKK Switches	SWITCH ROTARY 2-3POS 0.4VA 28V	9391142
44M45-04-1-07N Grayhill, Inc.	SWITCH ROTARY 85 DEG;C, 45 DEG 4	0
56SP30-01-4-02N Grayhill, Inc.	SWITCH ROTARY 2POS 200MA 115V	0
A11515RNCBE C&K	SWITCH ROTARY 3POS 0.4VA 20V	0
50KM36-01-1-10N Grayhill, Inc.	SWITCH ROTARY 36 DEG 1 DECK, 1 P	0
09M30-04-1-03N Grayhill, Inc.	SWITCH ROTARY 30 DEG 4 DECK, 1 P	0
44S30-01-2-04S Grayhill, Inc.	SWITCH ROTARY 4POS 1A 115V	0
09A30-03-6-02N Grayhill, Inc.	SWITCH ROTARY 2POS 250MA 115V	0
50AT45-01-1-08N-F Grayhill, Inc.	SWITCH ROTARY 8POS 150MA 115V	0
09M30-08-1-09S Grayhill, Inc.	SWITCH ROTARY 30 DEG 8 DECK, 1 P	0
KC50A30.001NPS E-Switch	SWITCH ROTARY 10POS 350MA 125V	0
50MP36-01-2-02N Grayhill, Inc.	SWITCH ROTARY MILITARY, PC MOUNT	0
50C45-01-1-04N Grayhill, Inc.	SWITCH ROTARY MILITARY W/O PANEL	0
A10415RNCB C&K	SWITCH ROTARY 4POS 0.4VA 20V	0
71BF36-06-2-05N Grayhill, Inc.	SWITCH ROTARY 5POS 250MA 115V	0
71MA30-01-1-03S Grayhill, Inc.	SWITCH ROTARY	0
50S36-01-2-02S Grayhill, Inc.	SWITCH ROTARY 2POS 150MA 115V	0

Rotary Switches

1. Overview

Rotary switches are electromechanical devices that use a rotating shaft to open or close electrical circuits. They enable multi-position switching through a circular arrangement of contacts. Widely used in industrial control systems, consumer electronics, and specialized equipment, these switches provide reliable manual control for complex operations. Their importance lies in offering precise configuration options in compact forms while maintaining robust electrical performance.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Single-Pole Multi-Throw (SPMT)	Controls one circuit with multiple output paths	Test equipment band selection
Multi-Pole Multi-Throw (MPMT)	Simultaneously controls multiple circuits with synchronized switching	Industrial machinery mode control
Pre-set Rotary Switches	Memory function with detent positioning	Audio equipment frequency tuning
Detent-Type Switches	Click-position feedback for precise alignment	Appliance timer controls
Illuminated Rotary Switches	Integrated LED indicators for position visualization	Medical device parameter selection

3. Structure and Components

Typical rotary switch construction includes:

Rotary shaft with precision indexing mechanism
Conductive contact segments (usually copper alloy)
Insulating substrate (phenolic resin or ceramic)
Protective housing (metal or high-temperature plastic)
Detent system for position stabilization

Advanced models incorporate EMI shielding, anti-corrosion plating, and sealed enclosures for harsh environments.

4. Key Technical Specifications

Parameter	Typical Range	Importance
Current Rating	0.1-10A	Determines load handling capacity
Voltage Rating	12-600VAC/DC	Defines circuit compatibility
Contact Resistance	5-50m	Impacts signal integrity
Insulation Resistance	>100M	Ensures electrical safety
Mechanical Life	10,000-100,000 cycles	Dictates maintenance intervals
Protection Rating	IP00-IP67	Environmental durability indicator
Rotation Angle	30 -360	Determines position count

5. Application Fields

Industrial automation (PLC control panels)
Consumer electronics (audio mixer controls)
Medical equipment (diagnostic device settings)
Automotive systems (HVAC control switches)
Aerospace (cockpit instrumentation selectors)

Example: In CNC machines, 4-pole rotary switches enable tool selection while maintaining electrical isolation between high-power and control circuits.

6. Leading Manufacturers and Products

Manufacturer	Country	Representative Product
OMRON	Japan	A6S Series heavy-duty switches
TE Connectivity	USA	ET Series sealed industrial switches
Eaton	USA	HS4 Series high-voltage switches
Nidec	Japan	EM-TSW precision audio switches
C&K Components	USA	7211 Series illuminated switches

7. Selection Recommendations

Define circuit requirements (voltage/current/load type)
Calculate required positions and pole configuration
Evaluate environmental factors (temperature/humidity/vibration)
Consider actuator type (knob size, locking mechanism)
Verify compliance with industry standards (UL/CSA/IEC)
Assess maintenance accessibility requirements

8. Industry Trends

Current development directions include:

Miniaturization with enhanced current capacity (down to 6mm mounting centers)
Integration with digital position sensors
Increased use of noble metal contacts for low-voltage applications
Development of RoHS-compliant actuator materials
Growing demand for panel-mount switches in IoT control systems