Pushbuttons: How they work and what they are used for

 

This means that it is a control element that can open or close the respective circuit by means of a circuit. The design and switching of these devices must therefore function as follows: It must be ensured that the switching contacts, which are live, are separated from the operating elements in such a way that they cannot be touched.

After the push-buttons have been pressed, they always return to their initial position, because the function behind them may only be carried out when they are pressed. Pushbuttons or also pressure switches can be installed in such a way that they can be operated by people, for example as on/off switches for power tools or household appliances and as light switches. They therefore come in the form of foot switches or handles.

However, there are also push-buttons and switches that are installed invisibly in the area of limit switches or alarm contacts and also in the area of electrical devices or on windows and doors to be secured. Pushbuttons and other triggers are used and installed in commercial, but also in some private applications.

A normally closed pushbutton releases the connection between two contacts, while a normally open pushbutton establishes the connection between two contacts. As mentioned above, the special mode of operation of a pushbutton is that it always returns to its initial position after being pressed.

This means that a pushbutton only performs its function while it is pressed. A switch, on the other hand, remains in its position after being pressed. In addition to electric push-buttons, there are also non-electric variants of these mechanisms. The keys of a piano, for example, belong to the non-electrical variant of push-buttons. This is because the actuating travel of each individual key on this instrument is non-electrically operated. A push-button, so to speak.

The electrically operated triggers, on the other hand, work with the movement of the contacts and can also perform two-level switching. In addition, they partly work with the principle of the Hall effect. It is precisely the Hall effect that enables over millions of switching cycles and thus favours a long service life of the releases.

The switching voltage of the releases ranges from 1.5 V up to 400 V. A 230 V pushbutton is therefore approximately in the middle of the possible switching voltage. The maximum switching current ranges from 0.0015 amperes to 20 amperes. A further distinction between the different releases concerns the colour of the signal and light sources of the releases.

These are very different, as the type of illuminant ranges from incandescent lamp, glow lamp, LED to neon lamp. The material of the triggers also varies from plastic to metal. There are many other distinctions between the different types of triggers, each of which is listed with the different models. This is because the protection class also often differs. Depending on the use of the releases, complete protection against contact, dust-tightness and protection against water must be guaranteed.

A special type of release - due to its flat design - is the membrane switch, which is used for electronic devices (e.g. TV and audio systems). Coarse hand or foot switches, on the other hand, are characterised by their good visibility and easy operability and are mostly used in emergency shutdowns.

In addition, there are also handles in which, on the other hand, handle switches are embedded. With these, tools can not only be guided but also switched at the same time. To sum up, it can therefore be said that the type of the different releases and their applicability are very different. For example, protection against vandalism is a major advantage of many triggers used in public spaces.