Difference between revisions of "Switches"

From OpenCircuits
Jump to navigation Jump to search
(Adding link to switch terminology page)
(linkify to article that goes into more detail, etc.)
 
(19 intermediate revisions by 7 users not shown)
Line 1: Line 1:
[[Switch Terminology]] _P_T - SPST - SPDT - DPST - DPDT - 3PDT - ....
+
== Switch Basics ==
 +
{{mergefrom|Switch Terminology}}
  
[[Image:Main-G5Q-14.jpg|69px|Relays]] [[Relays]] - Use these to control large power sources that a microcontroller cannot do alone
+
 
 +
A switch is often to turn something on or off. In the simplest case it is just a wire that is connected or not. Unplugging an appliance is one way to switch it off. A switch is usually a mechanical device where some sort of handle connects or disconnects conductors inside the switch. Another way of thinking of a switch is that it is like a resistor that sometimes has infinite resistance and sometimes has 0 resistance. A computer keyboard is made of a large number of switches. Some switches stay in the on or off position, others only stay on or off while you switch them, these are called momentary switches. A light switch is normally not momentary, a doorbell switch normally is momentary.
 +
 
 +
Uses:
 +
*On Off control
 +
*Range change, as in a meter
 +
*Data input
 +
 
 +
Links
 +
*[http://en.wikipedia.org/wiki/Electrical_switch Switch From Wikipedia,the free encyclopedia ( inc. Schematic and Picture )]
 +
*[http://www.kpsec.freeuk.com/components/switch.htm Switches]
 +
* [[Switch Terminology]] _P_T - SPST - SPDT - DPST - DPDT - 3PDT - ....
 +
 
 +
== Relays ==
 +
{{mergefrom|relays}}
 +
 
 +
A [[relay]] is a switch that is turned on and off by an electro-magnet. (So-called "solid state relays" do not use an electro-magnet ).  Like other switching devices it allows a small amount of power to control a large amount of power.  A nice feature of relays is that there is no electrical connection between the control circuit and the circuit connected to the switch. ( this is called electrical isolation ).  They are often used to let low power digital circuits control normal 110v power in a home.
 +
 
 +
Uses:
 +
*Turn on several circuits with one control circuit.
 +
*Control motors.
 +
*Isolate a low voltage circuit from power line.
 +
*Reverse current ( double pole double throw relay )
 +
* [[relay CPU]]
 +
 
 +
Links
 +
 
 +
*[[Image:Main-G5Q-14.jpg|69px|Relays]] [[Relays]] - Use these to control large power sources that a microcontroller cannot do alone
 +
*[http://en.wikipedia.org/wiki/Relay Relay From Wikipedia, the free encyclopedia]
 +
*[http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=119 Controlling Big, Mean, Devices]
 +
*[http://www.kpsec.freeuk.com/components/relay.htm Relays]
 +
*[http://cp.literature.agilent.com/litweb/pdf/5988-6917EN.pdf Maximizing the Life Span of Your Relays]]
 +
*[[Driving_Large_Loads_with_the_Arduino#Relay Driving Large Loads with the Arduino]]
 +
*[http://relays.tycoelectronics.com/appnotes/ Tyco Electronics Application Notes]
 +
 +
 
 +
[[Category:Components]]

Latest revision as of 18:40, 29 January 2024

Switch Basics[edit]

It has been suggested that [[::Switch Terminology|Switch Terminology]] be merged into this page or section. (Discuss)


A switch is often to turn something on or off. In the simplest case it is just a wire that is connected or not. Unplugging an appliance is one way to switch it off. A switch is usually a mechanical device where some sort of handle connects or disconnects conductors inside the switch. Another way of thinking of a switch is that it is like a resistor that sometimes has infinite resistance and sometimes has 0 resistance. A computer keyboard is made of a large number of switches. Some switches stay in the on or off position, others only stay on or off while you switch them, these are called momentary switches. A light switch is normally not momentary, a doorbell switch normally is momentary.

Uses:

  • On Off control
  • Range change, as in a meter
  • Data input

Links

Relays[edit]

It has been suggested that [[::relays|relays]] be merged into this page or section. (Discuss)


A relay is a switch that is turned on and off by an electro-magnet. (So-called "solid state relays" do not use an electro-magnet ). Like other switching devices it allows a small amount of power to control a large amount of power. A nice feature of relays is that there is no electrical connection between the control circuit and the circuit connected to the switch. ( this is called electrical isolation ). They are often used to let low power digital circuits control normal 110v power in a home.

Uses:

  • Turn on several circuits with one control circuit.
  • Control motors.
  • Isolate a low voltage circuit from power line.
  • Reverse current ( double pole double throw relay )
  • relay CPU

Links