Transcript Control Systems - U.Va. School of Engineering and Applied

Control Systems
An introduction to basic control
system design and implementation
Application Notes Posted
Definitions

Control System – A component or set of
components which determines the
operation or behavior of interconnected
equipment either manually,
automatically, or with some combination
of both.
What types of things would we want
to control?
Definitions

Manual Control Systems use some type of
user interface to allow a person to direct the
actions of machinery or other devices.
 Automatic Control Systems direct the
actions of machinery or other devices without
the need for human intervention.
 A Feedback Loop provides information about
the current state of a controlled device which
is then processed in some manner to augment
or fine tune the control of a system.
Switch Definitions
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Contacts – Conductors within a switch which touch to
make an electrical (closed) connection
Open – A switch’s contacts are not touching so the
switch (or portion thereof) is OFF
Closed – A switch’s contacts are touching so the
switch (or portion thereof) is ON
Poles – The number of sets of contacts of a switch
Throw - The number of different routes through which
current can flow through a switch
Types of Common Switches
Toggle
Rocker and Slide
Push Button
Rotary
Types of Special Switches
Tilt
Magnet
Key
Snap Action
Types of Special Switches
Relays
Switch Classifications

Switches are classified by:
Number of Poles
SPST Toggle & Pushbutton
(Single Pole Single Throw)
 Number of Throws
On-Off (On)-Off On-(Off)
 Rated Current
 Rated Voltage
 Type of Switch
 Switch Action

Switch Classifications
DPDT Slide
(Single-Pole 6-Throw)
On-Off-On
SP6T Rotary “Selector”
(Single-Pole 6-Throw)
DPDT Example

The Polarity
Reversing Switch
(See “A Presentation
of Random Material
in a Nonsensical
Order” for a review
of operation)
Rotary Switch Example

Use rotary switch to
select between
balloons to pop
Introduction to Logic
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For logical systems, there can only be
two values, for example:
On or Off
 True of False
 High or Low
 ‘1’ or ‘0’
 5 Volts or Ground (0 Volts)

Where will you use Logic?
Computer Science – Boolean
Statements, flow control, IF/THEN
statements in Programming
 Electrical Engineering – Digital Logic in
things like basic logic chips all the way
up to computers
 Philosophy – “If the world was a perfect
place then…”
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Logic Functions: NOT
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NOT – The inversion of a single input’s value
Truth Table
Input
Output
ON
OFF
OFF
ON
Symbol
Logic Functions: OR
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OR – The output is ON if one or more of the
inputs are ON.
Truth Table
Input
Symbol
Output
A
B
OFF
OFF
OFF
ON
OFF
ON
ON
OFF
ON
ON
ON
ON
Logic Functions: AND

AND – The output is ON only if both inputs
are ON.
Truth Table
Input
Symbol
Output
A
B
OFF
OFF
OFF
ON
OFF
OFF
ON
OFF
OFF
ON
ON
ON
Logic Functions: XOR

XOR – “Exclusive OR” Where the output is
ON if only one input is ON
Truth Table
Input
Symbol
Output
A
B
OFF
OFF
OFF
ON
OFF
ON
ON
OFF
ON
ON
ON
OFF
Example NOT Implementation

Light turns OFF when (normally closed)
button is pressed
Example OR Implementation
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Light turns ON when either (normally
open) pushbutton is pressed
Example AND Implementation
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Light turns ON when both (normally
open) pushbuttons are pressed
Efficient Control Wiring
Or…How to not have spaghetti in
front of the stage.
Efficient Control Wiring
Efficient Control Wiring
Efficient Control Wiring
Efficient Control Wiring
Efficient Control Wiring
Efficient Control Wiring
Grid Outlet
Control Position
Efficient Control Wiring
Using Relays
Why did you bother mentioning
these things, anyway?
Simple Relay Circuit for 120VAC
Simple Relay Circuit for 12VDC
Relay Reversing Circuit
Relay Reversing Circuit
Control Systems Topologies
Let’s Explore Several Common
Theatrical Control Systems and
Their Topologies and Distributions
Sound System Layout
Sound System Layout With Snake
A Closer Look at the Snake
Lighting Control System
Jazz Night 2006
Jazz Night 2006
Lighting System
Details:
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38 PAR38 150W
Incandescent
Fixtures
5700 Watts of Power
22 Remote
Controllable Dimmers
4 Separate Wall
Circuits
10 Channels of
Control
Jazz Night 2006
Stage Lighting System
Power Distribution
Power
Control
Cable
Dimmer
Lights