We are surrounded by machines. Especially in industrial environments, machines are everywhere. People control machines and our lives become easier. When we want machines to start, stop and do different tasks, we need some interfaces. This is where push button switches come into play. Push button switches have various types each having a different function.
Before looking at the types, let’s define what a push button switch is.
The push button switch is an electrical device that transfers the operator’s pushing action to the machine. It helps the operator to make more accurate decisions and maintains control of the system. The function of the push button switch is to start and stop the machine.
Push Button Switch Types
Push button switches have various types. Some of them are:
1. Flush push button switch
The flush push button switch requires direct pressure on the operator’s surface. It has the actuator flush with the mounting ring and is often used for start buttons that need to be protected from accidental initiation.
2. Extended push button switch
The extended push button switch has the actuator protruding about ¼ inch beyond the mounting ring and allows easier activation because the machine operator does not need to place a finger squarely on the actuator to operate the push button. It is usually used for the most prominent commands on an automation panel.
3. Mushroom push button switch
The mushroom-head push button switch has an actuator that extends over the edges of the mounting ring and has a diameter larger than a standard push button. Because of their size and shape, mushroom-head push buttons are more easily seen and actuated and for these reasons are used as emergency stop buttons.
4. Emergency stop push button switch
It demands a more active decision on behalf of the worker to reset a control function.
5. Illuminated push button switch
The illuminated push button operator unit often uses integrated light-emitting diodes (LED) to provide the desired illumination. The illuminated push button switch combines illuminating and actuating functions in one operator. It saves space and cost.
6. Double push button switch
The double push button switch combines two operators in the same body. It saves space and cost. Besides, some models have an illumination function.
Color Coding of Push Button Switches
Every color of a push button switch has a different meaning.
Parts of a Push Button Switch
The construction of a push button switch consists of different parts.
The conducting part of a switch that makes or breaks a circuit. Available as “normally open”, in which the circuit is open in its neutral state, or “normally closed”, in which the circuit will be closed. The activation of the operator will reverse the neutral state of the contact.
The part of a push button that encapsulates the contact. Blocks are held to the back of a device with a contact block holder.
Operator / Actuator
The part of the device that is touched to operate.
The part of a push button that holds and activates the light bulb when it receives the appropriate signal.
Operating Types of Push Button Switches
A circuit that remains closed after pressure is released from the button. Momentary-type push button operators return to their normal on or off state as soon as the operator is released.
A closed circuit that lasts only as long as pressure is maintained on the button. Unlike momentary push button operators, maintained types require you to press and release the operator to switch the contacts to their “on” state and to press and release the operator a second time to return the contacts to their off state.
Modular and Compact Push Button Switches
The manufacturer’s push-button series generally consists of two different types: Modular and compact.
Modular models are installed by combining the head, holder, and auxiliary contact of the button like a LEGO. In case of a project revision, these parts can be changed easily.
Compact models are all-in-one models. When there is a project revision, the whole push button must be changed. Compact models are more affordable than modular ones.