Electronics: Switches Flashcards
What are switches and how are they different from potentiators?
Switches always control simple open/close operations; they are not used for fine-tuning varying levels of current in a circuit.
How are the open and closed states of a switch represented in binary?
0 = open 1 = closed
What are the conductive parts of a switch called?
contacts
What is the difference between an actuator and an actuation?
A mechanical force is controlled by an actuator which brings the contacts together or apart. The force required to move the actuator is is called an actuation force.
What are poles and throws
Poles are each contact that copletes a ciruit.
A throw is one of the several positions that will allow a switch to make pole connections
What are different ways to classify a push button switch?
n. o - normally open, or BBM -break before move
n. c. normally closed, or MBB-move before break
What are different ways to classify actuator switches
SPST -single pole single throw
SPDT - single pole double throw
DPST double pole single throw
DPDT -double pole double throw
What is Arching?
The insulating air between the contacts can become ionized and the gas/current mixture forms an electric arc.
How can arching be prevented?
enclose the switch in an insulating gas mixture such as sulfur hexafluoride
or use a magnetic blowout that redirects any arc.
What is a mercury switch?
A mercury switch is operated by the gravitational effect on a ball of mercury in a vacuum tube. The mercury will always go to the lowest part of the tube. If the tube is rolled to the side, the mercury will change where it makes contact.
What are the advantages of a mercury switch?
Dont produce sparks and doesn’t corrode from repeated metal on metal contact
Slide switch?
A slide switch can have one or more poles, with each stop on the slide making or breaking the connection.
ition.
Toggle switch
A toggle switch is operated by a lever or rocking mechanism. Think of the little toggle switch on a guitar amplifier.
Edition.
Toggle switch
A toggle switch is operated by a lever or rocking mechanism. Think of the little toggle switch on a guitar amplifier.
Rotary Switch
A rotary switch has multiple pins that when rotated can make a connection. An example is the knob of a three-speed fan or the cycle selector on a basic washer or dryer.
Rocker Switch
A rocker switch is the type of switch that you may see on your surge protector; a push on the raised portion of the switch will activate the other position.
Keylock switch
A keylock switch is activated with the action of a key in the lock; think of your car’s ignition as one example.
What is contact bounce?
When a mechanical switch is actuated and the contacts meet, they may create a bit of noise (an unwanted signal that interferes or obscures the electrical signal you intend to transmit) by the physical properties of the two contacts coming together. This is called contact bounce.
What is a relay switch?
A switch that uses an electromagnetic field to control the opening and closing of a circuit is called a relay.
Which switches are mechanical?
Actuators, push-button, knife, bi-metal, mercury
Which switches are electromagnetic?
Relay switches
