Switch
Contents |
[edit] Introduction
A ‘switch’ is typically an electrical device which can either be turned on or off, depending on whether the requirement is to activate an electric circuit (turn on) or close it (turn off). Switches can be used to turn on/turn off lights and other electrical appliances and are used for a myriad of other domestic, commercial and industrial applications; this includes changing TV channels, pressing the keys on a computer keyboard and activating/deactivating car door-opening mechanisms.
[edit] How it works
When a switch is turned on, an electrical circuit is completed, allowing electric current to flow, causing the activation of the desired effect (e.g to turn a light on). Closing the switch (off position) breaks the circuit and stops the effect in question.
[edit] Manual v automatic
Switches can be activated manually or automatically:
Manual-type examples:
Automatic-type examples:
- Central heating on-off timer.
- Automatic pump.
- Smoke alarm.
As there is usually no manual activation with automatic switches, there must be an agent that causes the switch to activate. In an automatic pump, for instance, that agent is water: when the water level reaches a predetermined level, it completes a circuit causing the pump to operate. When the water level drops, the circuit is ‘broken’ and the pump stops.
[edit] Toggle
Another type of switch is a ‘toggle’ – a manually activated switch that has a protruding lever which makes it easy to actuate banks of toggle switches that need to be activated or deactivated simultaneously.
[edit] Railroad switch
A ‘switch’ in the railway sector is a mechanical device that allows a railway track to be ‘switched’ from one position to another, thereby diverting a train onto a different track. This type of switch is sometimes referred to as ‘points’.
[edit] Related articles on Designing Buildings Wiki
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
Bridging the gap between clients and contractors
Concerns remain around contractor quality, capability, and delivery.
Construction Management, 10 June.
Heat pumps beat boilers in new home tests.
Building Safety Act implementation in Wales
CIAT to host industry panel on 26 June.
New and updated CLC building safety guidance.
New UK National Buildings Database.
Building Safety Wiki Interviews
Chief executive of the British Woodworking Federation.
Planning condition discharge in England and Wales
A brief explanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
Shading for housing, a design guide
From the Good Homes Alliance and British Blind and Shutter Association.
UK Standard Skills Classification (SSC)
A shared framework for describing skills needs.
Social media ban consultation comes to close
CIOB urges UK Government to consider social media’s role in careers guidance in ban debate.