Push button switches are crucial for operability control systems in Electronics or machinery across numerous applications such as appliances and industrial systems. This article focuses on highlighting the differences in the push button on and off symbols, and offers some guidance on how to select the suitable switch for particular applications, allowing you to make reasoned decisions in the context of circuit design. So, its better not to skip!

1) What is a push button switch

“A push button switch is an electrical device that is used to make or break a circuit by means of pressing a button.”

It is used in everyday practices like opening a door bell, an elevator, or switching on an appliance or any other electronic device. when the button is pressed, the switch either makes (closes) or breaks (opens) the circuit, which permits or stops the flow of current.

Generally, pushing the button back restores the circuit and the system turns to its former conditions. But, some push buttons are called latching switches they do not return back they remain to the place where they have been pressed till the time they are pressed once again.

There are switches with buttons made of plastic or metal, which can be pressed, and those buttons are connected to internal contacts which control the closing or opening of the electrical connection. When the button is pushed, the contacts touch and complete a circuit, but when the button is released, the contacts separate and break the circuit.

2) Common push button switch symbols and meanings

Here’s a brief revelation of initial push-button off and on symbols to help withstand confusion for those beginning to dive into the specifics of applications ( especially electrical switches symbols).

i) Normally Open (NO) Push Button Symbol

The symbol for a momentary push button switch normally open NO type, is usually drawn as two lines or are separated with a gap and with the indication which says ‘push’.

It means that on its own, this type of switch remains open and not connected until the button is pressed. On being pressed, the switch closes, hence current can flow through. On release, the switch goes back to its original state which is open.

ii) Normally Closed (NC) Push Button Symbol

In an NC pushbutton switch ( Switch off symbol), there are two pins or touch lines which are separated and open after being pressed by a break indication that could probably be a push language.

The NC switch also has the SWITCH=ON position that is OFF when in relaxed position of that particular. Pressing the NC switches cuts OFF current flow momentarily. When lifted, it goes back to its original position.

iii) Momentary Push Button Symbol

A momentary push button symbol is often similar to the NO or NC symbol with some additional marking to indicate that it is of momentary type or is meant for temporary switch connections.

A momentary switch only changes the state of circuit (open or closed) when force is applied on it, and when the force is removed it returns back to its original state. Also both, NO and NC push buttons can be momentary.

iv) DPST Push Button Symbol

The DPST push button symbol has two lines in parallel form containing an open circuit on one side and closed circuit on the other.

This switch is designed to provide control over two different electrical circuits simultaneously. It caters for situations when a single command is required to start two different circuits.

v) DPDT Push Button Symbol

The basic design incorporates two horizontal lines with gaps that make it possible for the device to house circuits with switches to enable the user change between the two circuits.

The device contains two circuits, with both having two outputs. Upon being pressed, the device cuts off the circuits to the usual path and directs them to the alternate path.

vi) Push Button With Delayed Action

The symbol consists usually of a traditional pushbutton with an hourglass added to it. This makes it visually interpretable when the button is pressed and how much time has elapsed since the action occurred.

vii) Mushroom Head Pushbutton

The symbol consists of a mushroom-like cap situated above it that is usually drawn higher than the rest of the part. This may be inscribed with the word “STOP” or an emergency sign and is implemented for emergency stop purposes and usually draws in red color.

vii) Maintained Contact One Double Circuit

This symbol key has two parallel lines whose meaning is circuits attached to a single push button which has the marking M or some marking for maintained contact. It infers that for pressing the button, both circuits devices are closed.

viii) Maintained Contact Two Single Circuits

This sign depicts two circuits composed separately, each containing a pushbutton sustaining contact which is held on by an M inscribed in the circuit. It implies two circuits controlled independently, each maintained after it has been pressed.

ix) Fast Closing Pushbutton

A fast-closing pushbutton symbol includes a button with arrows that indicate a quick push-button closure. Such types of pushbuttons are built to be pressed quickly and are AFPM or Automatic Frequency Power Management for machines or devices that need instant connection or engagement once pressed.

x)Fast Opening Pushbutton

Line drawings are also used in this symbol to represent fast disconnection. Such push buttons are used in most settings. But, in cases where safety emergency layouts require quick release actions, these buttons are handy.

xi) Pull Cord Pushbutton

A pull cord pushbutton symbol uses images of cords as a means of activation by thighs also pulling rather than pressing. This pushbutton is mainly used in places such as conveyor belts or assembly lines.

xii) Padlock Pushbutton

Push Button Padlock symbols are also available and consist of a small padlock in the easily lockable symbol on the button. An attractive feature of this button is its ability to be locked in actuated or non- actuated positions so that no more chances of accidental activation.

3) Common button function symbols and meanings

The following are a few of the more prevalent button function symbols and their meanings:

i) Power Button Symbol

The symbol which denotes the power button is described by a circle with a line crossing it at the top. Engaging it often leads to the turning on or off the device.

This is usually the case chalked on electronic devices signifying what usually is a clear user instruction on how to switch the device off or on.

ii) Play and Pause Symbols

Typically depicted as a triangle facing right, the play button allows you to initiate a media item, such as a video clip or a melody.

On the contrary, the pause button is denoted by two vertical bars on the screen. The button allows the user to stop the media without quitting it entirely. Most of these symbols can be seen on media players, remote controls and streaming platforms.

iii) The Stop Symbol

The stop button is solid square in shape and when pressed, it is an absolute halt of whatever media or process being worked on.

The audio & video players consist of this symbol and it can be pressed to stop the playback and usually it is reset to the beginning.

iv) Fast Forward and Rewind symbols

The fast forward symbol is a button that shows two triangles pointing towards the right which means moving quickly through the particular media.

Conversely, on the other hand, the rewind symbol is represented by two triangles facing left which indicate moving backward. Both symbols are standard on media players and remote controls.

v)The Volume Control Symbols

Low volume is depicted by a loudspeaker icon/graph which has less amplitude compared to the one showing a loudspeaker with sound waves which implies a high volume.

A dull speaker symbol indicates mute, which can be effective immediately. Icons are utilized in audio devices, remotes, or even in software applications.

vi) Reset Button

This Symbol is often represented with a more circular arrow or a triangular shape in the middle of the larger circle, it can be observed that the reset symbol has a single defined purpose; putting the device turned on back to its original settings. Such actions are common on devices and on occasion should be expected so as to resolve some errors or system malfunctions.

4) Pushbutton switch symbols quick reference table

Alright, so here’s a quick reference table for common push button switch symbols including their meanings:

Symbol	Meaning	Function	Symbol
Normally Open (NO)	Usually two lines with a gap between	Circuit closes only when pressed
Normally Closed (NC)	Two lines touching, breaks when pressed	Circuit opens when button is pressed
Momentary Switch	Resembles NO or NC with “momentary” label	Only active while being pressed
Double-Pole Single-Throw (DPST)	Two parallel lines, each with a gap or connection	It controls two circuits simultaneously
Double-Pole Double-Throw (DPDT)	Two rows with alternate pathways	It switches two circuits between paths
Pushbutton with Delayed Action	A button with a built-in time delay.	Activates or deactivates after a set delay, used when a time lag is required.
Mushroom Head Pushbutton	A large, rounded emergency stop button.	Quickly pressed to stop operations in emergencies.
Maintained Contact One Double Circuit	A button that keeps two circuits engaged.	Keeps both circuits closed after being pressed for continuous operation.
Maintained Contact Two Single Circuits	A button that maintains contact for two circuits.	Keeps each circuit engaged independently after pressing.
Fast Closing Pushbutton	Shows a pushbutton with arrows or lines indicating rapid closure	Allows for quick activation, ideal where immediate connection is needed
Fast Opening Pushbutton	Symbol with arrows or lines indicating rapid disconnection.	Enables swift disconnection, used in systems requiring fast disengagement/ emergency stopping.
Pull Cord Pushbutton	Often shows a pull cord icon alongside the pushbutton, indicating activation by pulling.	Used in environments where pulling a cord is easier or safer than pressing a button.
Padlock Pushbutton	Symbol includes a padlock icon near the button, signifying a lockable feature.	Designed to be locked in position, preventing unauthorized use or accidental activation.

5) Common errors in the use of pushbutton switch symbols in circuit design

In circuit design, pushbutton switch symbols as design elements have the following common errors which may result in misunderstanding or circuits malfunction:

? Difficulties in distinguishing between NO and NC Symbols: The mixing up of symbols may lead circuits operating the reverse, like being accidentally switched on or off.

? Incorrect use of Momentary and Latching Symbols: Using a symbol for momentary or latching switch incorrectly may lead to a situation whereby the circuit will not be closed or broken as expected.

? Absence of Indicator Lights: Not including or placing the indicator light symbol fogs or muddies the perspective of the user as to the state of the circuit in cases of control panels.

? Absence of proper DPST and DPDT Symbols: Absence of the correct symbols of double-pole switches may lead to uncoordinated control of circuit.

6) FAQ

1. What is the difference between a momentary and a latching push button switch?

A momentary switch is active only when pressed down while latching switch will be in the last position where the user has pressed it last.

2. How do I choose the right push button switch for my circuit design?

Evaluate the required function (momentary or latching), the type of circuit, the voltage, the size of the components, and their endurance to achieve the best performance in your design.

3. How can I tell if a push button switch symbol is normally open (NO) or normally closed (NC)?

A properly designed Normally open NO has two lines apart and normally closed NC this has lines close to each other.

4. Can I use push button switch symbols interchangeably in different standards (IEC, ANSI, JIS)?

There are variations in the pushbutton symbols used in IEC, ANSI and JIS standards. So, make sure of compatibility but do not use interchangeably without verification.

5. What should I do if the push button switch symbol I need is not available in my design software?

If any standard symbol is missing, you manage to make that particular symbol with the help of the software or alternatively use a relevant symbol with the correct title for clarification.