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Questions and Answers
What is the primary purpose of an electrical switch?
What is the primary purpose of an electrical switch?
Which of the following best represents a characteristic of process switches?
Which of the following best represents a characteristic of process switches?
What does the term 'normal' state refer to when discussing switch contacts?
What does the term 'normal' state refer to when discussing switch contacts?
Which section of the document would you find information about electrical switch types?
Which section of the document would you find information about electrical switch types?
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What does 'pole and throw' refer to in switch terminology?
What does 'pole and throw' refer to in switch terminology?
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In the context of electrical symbols, what does generic symbology refer to?
In the context of electrical symbols, what does generic symbology refer to?
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Which objective focuses on the understanding of switch types and contacts?
Which objective focuses on the understanding of switch types and contacts?
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What is the significance of the review section in the document?
What is the significance of the review section in the document?
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What feature distinguishes pushbutton switches that stay in their 'in' position?
What feature distinguishes pushbutton switches that stay in their 'in' position?
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How do selector switches differ from toggle switches?
How do selector switches differ from toggle switches?
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What is a primary use of joystick switches?
What is a primary use of joystick switches?
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What type of switch is designed to operate based on machine motion?
What type of switch is designed to operate based on machine motion?
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Which type of limit switch is equipped with a lever actuator?
Which type of limit switch is equipped with a lever actuator?
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What does a proximity switch detect?
What does a proximity switch detect?
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Which feature is NOT typical of joystick switches?
Which feature is NOT typical of joystick switches?
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What is the primary function of limit switches in machinery?
What is the primary function of limit switches in machinery?
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What is the primary function of the Nuclear Level Switch described?
What is the primary function of the Nuclear Level Switch described?
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How does the radiation from the source affect the detector?
How does the radiation from the source affect the detector?
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Which type of contacts will connect the circuit when a relay is activated?
Which type of contacts will connect the circuit when a relay is activated?
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What is true about the radioactive sources used in the Nuclear Level Switch?
What is true about the radioactive sources used in the Nuclear Level Switch?
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Why is it necessary to intelligently match switches to their tasks?
Why is it necessary to intelligently match switches to their tasks?
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What is the purpose of the relay mechanism in the context of the Nuclear Level Switch?
What is the purpose of the relay mechanism in the context of the Nuclear Level Switch?
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Which statement about the arrangement of the radioactive source and detector is correct?
Which statement about the arrangement of the radioactive source and detector is correct?
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What is a common characteristic of Normally-closed (NC) contacts?
What is a common characteristic of Normally-closed (NC) contacts?
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How does the brass bulb switch mechanism operate?
How does the brass bulb switch mechanism operate?
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What role does conductivity play in a liquid level switch?
What role does conductivity play in a liquid level switch?
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What is a common design for detecting solid materials in a storage bin?
What is a common design for detecting solid materials in a storage bin?
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What triggers a flow switch when detecting liquid or gas flow?
What triggers a flow switch when detecting liquid or gas flow?
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Why is it usually impractical to switch full load current through a conductive liquid in liquid level switches?
Why is it usually impractical to switch full load current through a conductive liquid in liquid level switches?
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How does a tuning fork level switch operate?
How does a tuning fork level switch operate?
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What is a differential pressure switch in a flow detection system designed to measure?
What is a differential pressure switch in a flow detection system designed to measure?
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What type of materials can level switches detect in addition to liquids?
What type of materials can level switches detect in addition to liquids?
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What does a normally-open switch signify in its schematic representation?
What does a normally-open switch signify in its schematic representation?
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Which of the following best describes a normally-closed switch?
Which of the following best describes a normally-closed switch?
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In generic symbology, how are normally-closed contacts represented?
In generic symbology, how are normally-closed contacts represented?
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What is a common visual characteristic of a normally-open switch in control logic schematics?
What is a common visual characteristic of a normally-open switch in control logic schematics?
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Which of the following statements about switch representations is true?
Which of the following statements about switch representations is true?
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What should not be confused with the symbol of a normally-open switch?
What should not be confused with the symbol of a normally-open switch?
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What does the schematic representation of a capacitor ensure?
What does the schematic representation of a capacitor ensure?
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Which of these symbols would signify a normally-open switch in a control logic schematic?
Which of these symbols would signify a normally-open switch in a control logic schematic?
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Study Notes
Switches
- A switch is an electronic device that interrupts the flow of electrons in a circuit.
- Pushbutton switches can be latched on or off with every push or remain in the "in" or "pressed" position until the button is released.
- Selector switches use a rotary knob or lever to select one of multiple positions.
- Joystick switches use a lever that can move in multiple directions, and activate contact mechanisms based on the direction and force of the lever motion.
Process Switches
- Process switches are designed to be operated by the motion of a machine, rather than by human interaction.
- Limit switches are specifically used to limit the motion of a machine by stopping its actuating power if it moves too far.
- A lever actuator limit switch has a lever tipped with a roller bearing.
- Proximity switches detect the approach of a metallic machine part using a magnetic or electromagnetic field.
- Temperature switches use a brass bulb filled with liquid or gas, which expands and generates pressure as it heats up, activating the switch mechanism.
- Liquid level (float) switches use a floating object that activates a switch mechanism when the level of liquid rises above a certain point.
- Liquid level (float) switches can also detect the level of solid materials like wood chips, grain, coal, or animal feed.
- Liquid flow switches detect gas or liquid flow rates above a certain threshold using a paddle or vane.
- Flow switches can also be constructed as differential pressure switches, measuring the pressure drop across a restriction in the pipe.
- Nuclear switches use radioactive source material and a radiation detector to detect liquid or solid material levels by measuring the attenuation of radiation.
Pole and Throw
- The number of contacts on a switch is referred to as the number of "poles".
- The number of "throws" refers to the number of positions a contact can be thrown to.
- Normally-open (NO) contacts connect the circuit when the relay is activated and disconnect it when inactive.
- Normally-closed (NC) contacts disconnect the circuit when the relay is activated and connect it when inactive.
Generic Symbology
- Generic switch contact designation uses vertical lines to represent contact points.
- Normally-open contacts are represented by lines not touching, while normally-closed contacts are represented by lines connected with a diagonal line.
- The capacitor symbol in control logic diagrams uses a single vertical line to represent the capacitor to clearly distinguish it from a normally-open switch contact.
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Description
This quiz covers various types of electronic switches, including pushbutton, selector, joystick, and process switches. You will learn about their functionalities, applications, and mechanisms. Test your knowledge on limit switches, proximity switches, and temperature switches.