Search
Push button switches are everywhere. You press a doorbell. You tap a computer power button. You click a desk lamp on and off. These actions feel simple, but the switches behind them behave in very different ways.
For beginners, DIY builders, and entry-level buyers, the confusion often comes down to two terms: momentary switch and latching switch. They look similar on the outside, but their function is not the same. Choosing the wrong type can lead to wiring problems, unexpected behavior, or product returns.
This guide explains how momentary and latching push button switches work, how they differ mechanically, where each type is commonly used, and how to identify them quickly using simple tools.
What Is a Push Button Switch?
A push button switch is a device that controls an electrical circuit by being pressed. When the button moves, internal contacts either open or close the circuit. What happens after you release the button is what separates momentary and latching designs.
Understanding this behavior is easier if you focus on one question:
Does the switch return automatically, or does it stay in its new state?
What Is a Momentary Switch?
A momentary switch only stays active while you are pressing it.
- When you press the button, the circuit closes.
- When you release it, the circuit opens again.
This behavior is often described as “press to make, release to break.” Internally, a spring pushes the button back to its default position as soon as your finger leaves it.
A simple way to think about a momentary switch is a bicycle brake lever. The brake works only while you squeeze it. Let go, and the brake disengages automatically.
Common Momentary Switch Applications
Momentary switches are used when the action should happen briefly and stop on its own:
- Doorbells
- Car horns
- Computer power buttons
- Game controllers
- Reset buttons on electronics
In these cases, holding the switch continuously would not make sense. The system either reacts once or stays active only while the button is pressed.
What Is a Latching Switch?
A latching switch changes state every time you press it.
- Press once, and the circuit turns on.
- Press again, and the circuit turns off.
The switch stays in its current state until it receives another press. This is often called maintained action or push-on / push-off behavior.
A latching switch works like a wall light switch. You flip it, and the light stays on. You flip it again, and it turns off.
Common Latching Switch Applications
Latching switches are used when the device needs to remain on or off without constant input:
- Desk lamps
- Vehicle fog lights
- Guitar effect pedals
- Power switches on equipment
In these applications, the switch itself controls the system state directly.
Mechanical Difference: What Happens Inside?
| Feature | Momentary Switch | Latching Switch |
| Internal mechanism | Spring-loaded return | Mechanical locking structure |
| Button behavior | Returns automatically when released | Stays in position after pressing |
| Contact movement | Contacts close only while pressed | Contacts change state with each press |
| Reset method | Released by spring force | Released by the next button press |
| Typical feel | Soft press with immediate return | Firm press with a “click” or toggle |
Push Button Switch Function and Contact Types (NO vs. NC)
Many push button switches include NO (Normally Open) and NC (Normally Closed) contacts. These terms describe the circuit state when the button is not pressed.
- NO (Normally Open): The circuit is open at rest and closes when pressed
- NC (Normally Closed): The circuit is closed at rest and opens when pressed
Both momentary and latching switches can use NO or NC contacts. The contact type controls how the circuit behaves, while the switch type controls how long that behavior lasts.
Understanding NO vs. NC helps avoid wiring mistakes, especially in control panels and safety circuits.
Comparing Applications: Momentary vs Latching
The easiest way to choose between the two is to look at how the action should behave.
- A momentary switch fits applications where the system should respond briefly or only while the user applies force. A doorbell rings only while pressed. A horn sounds only while held.
- A latching switch fits applications where the system should remain on or off until changed. A lamp stays on after a single press. A fog light remains active until turned off.
If the system already includes electronic logic or software control, a momentary switch is often used as a trigger. If the switch itself controls power directly, a latching design is more common.
How to Quickly Identify a Momentary or Latching Switch
By Touch
Press the button and release it.
- If it immediately returns to its original position, it is a momentary switch.
- If it stays in a new position or feels mechanically “locked,” it is a latching switch.
This method works well for panel-mounted switches.
By Multimeter Test
Set a multimeter to continuity mode. Connect the probes to the switch terminals and observe the reading:
- Momentary switch: continuity appears only while pressed
- Latching switch: continuity remains after release
This test is useful when the mechanical feel is unclear or when the switch is already installed.
By Product Markings or Datasheets
Manufacturers often label switches using terms such as:
- Momentary, Spring Return, OFF-(ON)
- Latching, Maintained, ON-OFF, Push On / Push Off
Checking the datasheet avoids guesswork, especially for procurement or replacement tasks.
Which One Do You Need?
If the action should stop automatically when released, choose a momentary switch.
If the system should stay on or off until changed, choose a latching switch.
For beginners and DIY projects, understanding this single distinction prevents most wiring and selection errors.
Final Thoughts
Momentary and latching push button switches may look similar, but their behavior is very different. One responds only while pressed. The other remembers its state. Once you understand how each works and where it is used, choosing the right switch becomes straightforward.
Whether you are wiring a small project, replacing a control panel switch, or sourcing components, knowing how push button switch function, contact type, and mechanical action work together helps you make better decisions with fewer surprises.