A push button switch is an electromechanical device used to turn electrical circuits on or off by physically pressing or releasing a button. Push button switches provide a simple yet efficient way to control electronic devices and equipment.
In this guide, we will explore the 7 most common types of push button switches, their applications and factors to consider when selecting the appropriate switch.
What are Push Button Switches and How Do They Work?
A push button switch has a spring-loaded mechanism under the button or plunger. Pressing the button pushes the plunger down to close (turn-on) an electrical contact, allowing current to flow. Releasing the button breaks contact to open (turn-off) the circuit.
The main components are:
- Button or plunger: The part pressed by hand
- Contacts: Allow current flow when closed
- Terminals: For wire connections
- Spring: Provides restoring force to open contacts
Based on operating mode, push buttons are of two major types:
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Momentary: Contacts close only while button is pressed down. They open upon release.
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Maintained (or Latching): Contacts alternate between closed and open with each press and release. State is maintained without holding down the button.
Now let‘s look at the 7 common types of push button switches.
1. Power Push Button Switches
Power push button switches are designed to control high voltage/current electrical loads like motors, heaters, power supplies etc.
Features
- Voltage rating: Up to 600VAC
- Current rating: Up to 25A
- Contacts: Silver alloy for high conductivity
- 1NO/NC or 2NO/NC options
- Panel or surface mounting
- IP65 protection available
Applications
- Motor or generator control
- Switching lighting loads
- Turning power supplies on/off
A good example is the KA0-5 2 Position 380V 10A Push Button Switch.
It can handle 10A 380VAC loads. The green button is momentary while the red is latching. IP65 protection makes it dustproof and water jet resistant. Ideal for controlling high power machinery.
2. Illuminated Push Button Switches
Illuminated switches contain built-in LED lights to indicate status. Available in round or square shapes.
Features:
- LED colors: Red, green, yellow, blue etc
- Low voltage operation: 12/24V DC mostly
- Translucent button diffuses light
- Available with flashing or steady state LEDs
Applications:
- Control panels in machinery
- Audio/video equipment
- Gaming devices
- Automotive dashboards
For example, this round blue LED push button switch operates at 12V to provide bright visual feedback. Ideal for car dashboards or gaming equipment.
3. Waterproof Push Button Switches
Waterproof PB switches prevent damage in wet environments with sealing gaskets and IP65 or higher ingress rating.
Features:
- Sealing gasket
- IP65 or IP67 waterproof rating
- Stainless steel or polycarbonate body
- Mounting nut cover
- Available with LED indicator
Applications:
- Outdoor or marine equipment
- Car wash systems
- Swimming pool pumps
- Weather monitoring stations
The Wemos 16mm Blue LED Waterproof Metal Pushbutton Switch provides reliable operation in wet environments. IP67 rating, stainless steel body with sealing rubber gasket and LED indicator make it ideal for harsh conditions.
4. High Current Push Button Switches
High current switches can safely handle over 15-20A, making them ideal to switch motors, heaters and power transmission equipment.
Features:
- Current range: 15 to 25A
- Voltage: up to 600VAC
- Single or double-pole options
- Silver alloy contacts
- Two color options for ON/OFF status
Applications:
- 3-phase motors and pumps
- Magnetic contactors and braking resistors
- Heat processes like welding
CKN22012 offers 22mm diameter red/green body with 20A 600VAC rating, making it suitable for high capacity loads.
5. Miniature Push Button Switches
Mini PB switches feature compact 6x6x5mm size for applications with tight space constraints. Easy integration on densely packed PCBs.
Features:
- Compact dimensions: 6 x 6 x 5 mm typically
- SMT (Surface Mount Technology) for easy mounting on PCBs
- Available with LED lighting and waterproofing
- Ultra-low height options (~3mm)
Applications:
- Portable consumer electronics
- Office equipment
- Industrial process equipment
For example, the MCIGICM miniature push button switches offer durable plastic construction and easy surface mounting for flexible PCB integration.
6. Latching Push Button Switches
Latching PB switches maintain state between presses. Alternative action switch allows single press ON, second press OFF operation.
Features:
- Two position control
- Single-pole double throw (SPDT) contacts
- No need to hold down button
- Available with and without built-in LEDs
Applications:
- Stepper/servo motors
- Robotics
- Control relays
URBEST latching push buttons are versatile switches for broader compatibility. The self-locking mechanism also makes them useful across locations.
7. Mushroom Head Push Button Switches
Large exposed head allows easy operation and status visibility even with gloves on. Food processing and chemical plants often prefer them.
Features:
- Extended head diameter & height
- Stainless steel construction
- Industrial-grade performance
- Often come with LED indicators
Applications:
- Food processing equipment
- Industrial machine tools
- Chemical/pharma manufacturing
This 22mm red mushroom head provides an extended surface for convenient operation, even when wearing gloves and protective equipment common in factories.
How to Select the Right Push Button Switch?
Keep the following factors in mind when choosing a push button switch for your application:
Operating Voltage & Current
Select a switch rated to safely handle the operating voltage and current expected in your circuit.
Environment
Consider moisture, corrosion, temperature exposure etc. Harsh environments need appropriately sealed and constructed switches.
Size Constraints
Available panel cutout space and internal clearance determine suitable push button size and shape.
Force and Cycles Needed
The button plunger spring force and electrical/mechanical lifespan rating must align with your usage levels.
Contact Type
SPST, SPDT etc. contacts support different control needs. Select as necessary.
Approvals & Compliance
UL, CE marks indicate independently verified safety. Requirements vary across applications.
Understanding technical specifications is vital for long-lasting, trouble-free operation. Reach out to manufacturers if any doubt.
How to Install and Wire a Push Button Switch?
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Check switch ratings – operating voltage/current should match application
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Determine panel cutout and hole size needed
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Select appropriate wire gauge to safely carry expected load current
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Use insulated crimp connectors for reliable cable terminations
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Connect positive supply to common terminal on switch
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Connect load wires to the NO (Normally Open) points
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Test operation before final mounting to ensure proper wiring
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Install securely using the locknut or provided screws
Take precautions against shorts and shocks since push buttons switch live circuits!
Common Push Button Switch Problems & Solutions
Button pressing does not turn load ON/OFF
- Check wiring connections
- Faulty switch contacts – replace switch
- Load malfunctioning – test with another load
Switch feels stuck
- Dirt or debris accumulation – clean/replace
- Return spring fatigued – replace switch
LED not lighting up
- LED burnt out – replace switch
- Wiring polarity wrong – check connections
- Low voltage – check supply
Getting the right technical help quickly resolves most push button issues. We have experts on standby to assist further!
Conclusion
We have explored the working, types, selection factors, wiring and troubleshooting for push button switches. While they provide a simple interface, understanding technical specifications is important for smooth functioning.
Control panels, machinery, appliances and more – push button switches turn up everywhere and play a useful role. We hope this guide gives you clarity to choose and deploy them optimally in your own applications!
Check out more interesting guides on electrical devices like toggle switches and limit switches as well!
