Single Pole, Single Throw (SPST) Rotary Limit Switches
Last Updated: February 12, 2025
Description
Single Pole, Single Throw (SPST) Rotary Limit Switches are devices that control the connection of a single conductor in a single branch circuit. They function as simple on-off switches, making or breaking the connection based on the position of the switch.
Working Principle
SPST Rotary Limit Switches operate by means of a rotating shaft. When the shaft reaches a predetermined number of revolutions or a specific angle, the switch activates, either making or breaking the electrical connection. This simple mechanism is useful because it provides a reliable method for controlling electrical circuits with minimal complexity. The straightforward design of SPST switches makes them ideal for applications where a basic on-off control is sufficient.
Applications
SPST Rotary Limit Switches are commonly used in applications where a simple on-off control is required. Specific examples include:
- Stopping a length of rod or web at the correct cutting point.
- Slowing a fast-closing containment door before it crashes to the floor.
- Switching a loading system when the loaded pallet reaches a set level.
- Stopping a washing machine when the load becomes unbalanced.
Advantages over other Rotary Limit Switches
One of the primary advantages of SPST Rotary Limit Switches over other types of rotary limit switches is their simplicity. With only one pole and one throw, they are easier to install and maintain compared to more complex switches like SPDT or DPDT, which have multiple poles and throws. This simplicity can lead to reduced costs and increased reliability in applications where only basic control is needed.
Limitations
The main limitation of SPST Rotary Limit Switches is their lack of versatility. They can only control a single circuit and provide a simple on-off function. This makes them unsuitable for applications requiring more complex switching operations, such as those needing multiple circuits or directional control.
Considerations
When considering SPST Rotary Limit Switches, several factors should be taken into account:
- Initial Costs: SPST switches are generally less expensive than more complex switches due to their simple design.
- Operating Expense: The straightforward operation of SPST switches typically results in lower operating expenses.
- Durability: While durable, the mechanical nature of these switches means they may wear out over time, especially in high-use applications.
- Accuracy: SPST switches provide reliable on-off control but may lack the precision required for applications needing fine control.
- Replacement and Maintenance Costs: Maintenance is generally minimal, but replacement costs should be considered if the switch is used in a high-cycle environment.
from DigiKey
Switch SPST-NO Panel Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: "Quick Connect - 0.250"" (6.3mm)"
from RS Components, Ltd.
Limit switch, variable rod lever.DPDB [See More]
- Switch Configuration: Single Pole, Single Throw (SPST)
- Actuator Type: Wobble Type (Spring); Coil Spring
- Normal State: Normally Open; Normally Closed
- Connections: Screw Terminal
from DigiKey
Switch SPST-NO Surface Mount, Right Angle [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Gull Wing
from RS Components, Ltd.
Limit switch Flex rod Steel Pg13,5 [See More]
- Switch Configuration: Single Pole, Single Throw (SPST)
- Actuator Type: Wobble Type (Spring); Coil Spring
- Normal State: Normally Open; Normally Closed
- Maximum Current Rating: 10
from DigiKey
Switch SPST-NO Surface Mount, Right Angle [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Gull Wing
from RS Components, Ltd.
Limit switch Flex rod Coil spring M20 [See More]
- Switch Configuration: Single Pole, Single Throw (SPST)
- Actuator Type: Wobble Type (Spring); Coil Spring
- Normal State: Normally Open; Normally Closed
- Maximum Current Rating: 10
from DigiKey
Switch SPST-NO Surface Mount, Right Angle [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: SMD (SMT) Tab
from RS Components, Ltd.
Limit switch Flex rod G1/2 [See More]
- Switch Configuration: Single Pole, Single Throw (SPST)
- Actuator Type: Wobble Type (Spring); Coil Spring
- Normal State: Normally Open; Normally Closed
- Maximum Current Rating: 10
from DigiKey
Switch SPST-NO Surface Mount, Right Angle [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: SMD (SMT) Tab
from DigiKey
Switch SPST-NO Surface Mount, Right Angle [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: SMD (SMT) Tab
from DigiKey
Switch SPST-NO Surface Mount, Right Angle [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: SMD (SMT) Tab
from DigiKey
Switch SPST-NO Through Hole [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Solder Terminal; Solder Lug
from DigiKey
SWITCH SNAP ACT SPST-NO 0.1A 30V [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Gull Wing
from DigiKey
Switch SPST-NO Through Hole [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: PC Pin
from DigiKey
SWITCH DETECT SPST-NO 0.001A 5V [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: SMD (SMT) Tab
from DigiKey
Switch SPST-NO Surface Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Gull Wing
from DigiKey
SWITCH SNP ACT SPST-NC 0.1A 125V [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NC
- Normal State: Normally Closed
- Contact Type: Momentary Contact
- Connections: Wire Leads
from DigiKey
Switch SPST-NO Chassis Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Solder Terminal; Solder Lug
from DigiKey
SWITCH SNAP ACT SPST-NC 0.1A 12V [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NC
- Normal State: Normally Closed
- Contact Type: Momentary Contact
- Connections: SMD (SMT) Tab
from DigiKey
Switch SPST-NO Chassis Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: "Quick Connect - 0.250"" (6.3mm)"
from DigiKey
Switch SPST-NO Chassis Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: "Quick Connect - 0.250"" (6.3mm)"
from DigiKey
Switch SPST-NO Chassis Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: "Quick Connect - 0.250"" (6.3mm)"
from DigiKey
Switch SPST-NO Chassis Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: "Quick Connect - 0.250"" (6.3mm)"
from DigiKey
Switch SPST-NO Surface Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Gull Wing
from DigiKey
Switch SPST-NO Surface Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Gull Wing
from DigiKey
Switch SPST-NO Panel Mount, Snap-In [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: "Quick Connect - 0.187"" (4.7mm)"
from DigiKey
Switch SPST-NC Panel Mount, Snap-In [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NC
- Normal State: Normally Closed
- Contact Type: Momentary Contact
- Connections: "Quick Connect - 0.187"" (4.7mm)"
from DigiKey
Switch SPST-NO Chassis Mount [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Screw Terminal; Screw Terminal
from DigiKey
SWITCH DETECTOR SPST-NO 1MA 5V [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Normal State: Normally Open
- Contact Type: Momentary Contact
- Connections: Gull Wing
from SVF Flow Controls, Inc.
The NEXUS-PS is a low profile sensor that delivers valve position status in demanding environments (IP-67). The technology utilizes two reed devices that sense a magnetic target in the Open and Closed positions. The sensor element is SPST N.O. and the rotating component contains the magnetic target... [See More]
- Switch Configuration: Single Pole, Single Throw (SPST)
- Contact Type: Mantained Contact
- Switch Type: Electromechanical
- Maximum Current Rating: 0.3000
from Shenzhen Shengyu Electronics Technology Limited
SWITCH SNAP ACT SPST-NO 5A 125V [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Maximum DC Voltage Rating: 125
- Maximum Current Rating: 5
from Acme Chip Technology Co., Limited
SWITCH SNAP ACT SPST-NO 5A 125V [See More]
- Switch Configuration: Single Pole, Single Throw (SPST); SPST-NO
- Maximum DC Voltage Rating: 125
- Maximum Current Rating: 5
- Operating Temp: -20 to 125