Push Button Wiring

and

Output Signal Active Options

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Your comfort level with your responses to the following 10 question assessment tool should indicate if the presentation that follows will increase you knowledge base on the topic outlined by the questions in this tool.

Pre-presentation Self Assessment Activity

1. V+

Using the symbol

(a)

and together with

Configure the push button as an active low device.(b)Configure the push button as an active high device.

2. V+

Using the symbol

(a)

and together with

Configure the push button as an active low device.(b)Configure the push button as an active high device.

V+

Pre-presentation Self Assessment Activity

3.

V+

Label push button 1 as an active high or active low device.

Label push button 2 as an active high or active low device.

V+

V+

5.V+

Label push button 3 as an active high or active low device.

6. Label push button 4 as an active high or active low device.

V+

4.

Pre-presentation Self Assessment Activity

How may ways are there to wire a push button as an active low device?

7.

How may ways are there to wire a push button as an active high device?

8.

Pre-presentation Self Assessment Activity

A. Wire a normally open push button as an;

9.

(a) Active low push button.(actually draw this circuit to make sure you can

do it.)(b) Active high push

button.

(c) Active high push button.

B. Wire a normally closed push button as an;

(d) Active high push button.

(actually draw this circuit to make sure you can do it.)

(actually draw this circuit to make sure you can do it.)

(actually draw this circuit to make sure you can do it.)

Can a normally

10.

(a) open push button be used to make an active low output

device?

(b) open push button be used to make an active high output

device?

(c) closed push button be used to make an active low output

device?

(d) closed push button be used to make an active high output

device?

Pre-presentation Self Assessment Activity

Push Button Wiring

and

Output Signal Active Options

NO

NC

or

or

NO

NC

Push buttons come in two flavors

Normally Open

Normally Closed

NO

Push button wiring also comes in two flavors

Normally Open

(a)

V+

NO

Voltage value at this point?

The voltage value equals the value of V+

Note:

and are symbols for ground connections.

NO

Normally Open

(b)

V+

NO

Voltage value at this point?

The voltage value equals the value of 0 Volts

Note:

and are symbols for ground connections.

Push button wiring also comes in two flavors

Normally Closed

(a)

V+ Voltage value at this point?

The voltage value equals the value of ?

NC

NC V+

Note:

and are symbols for ground connections.

Push button wiring also comes in two flavors

Normally Closed

(b)V

+

Voltage value at this point?

The voltage value equals the value of ?

NC

NC 0 Volts

Note:

and are symbols for ground connections.

Push button wiring also comes in two flavors

Normally Open

Normally Closed

(a)V

+

NO

V+

(b)

V+

NO

0 Volts

(a)

V+

NC

V+

(b)

V+

NC

0 Volts

The 4 ways to wire a push button

Push button signals are labeled one of two ways

V+

NO

V+

(b)

V+

NO

0 Volts

(a)

Push button signals are labeled one of two ways

V+

NO

(b)

V+

NO

0 Volts

V+

(a)This is know as an active low output

When the push button is held down the low signal is on the wire.

Push button signals are labeled one of two ways

V+

NO This is know as an active high output

When the push button is held down the high signal is on the wire.0 Volts

(b)

V+

This is know as an active low output

When the push button is held down the low signal is on the wire.V

+

(a)

Push button signals are labeled one of two ways

(b)

V+

NO

PB1

This is know as an active high output

When the push button is held down the high signal is on the wire.0 Volts

Shorthand for describing a push button signal without drawing the wiring.

PB1 means this is push button number 1

When the push button is held down the low signal is on the wire.

The line over the top means that the button is an active low device.

Push button signals are labeled one of two ways

PB1

When the push button is held down the high signal is on the wire.

Shorthand for describing a push button signal without drawing the wiring.

PB1 means this is push button number 1

When the push button is held down the low signal is on the wire.

The line over the top means that the button is an active low device.

PB2

PB2 means this is push button number 2

No line over the top means that the button is an active high device.

Push button signals are labeled one of two ways

PB1

Active Low Push Button

When the push button is held down the low signal is on the wire.

The line over the top means that the button is an active low device.

Active High Push Button

Notice that by using this notation, you will know what signal (the high signal or the low signal) that will appear on the wire when the button is engaged without knowing how the button is wired!

When the push button is held down the high signal is on the wire.

PB2

No line over the top means that the button is an active high device.

Post Presentation Self Assessment Activity

1. V+

Using the symbol

(a)

V+

and together with

Configure the push button as an active low device.(b)Configure the push button as an active high device.

V+

2. V+

Using the symbol

(a)

V+

and together with

Configure the push button as an active low device.(b)Configure the push button as an active high device.

V+

3.

V+

Label push button 1 as an active high or active low device.

Label push button 2 as an active high or active low device.

V+

V+

5.V+

Label push button 3 as an active high or active low device.

6. Label push button 4 as an active high or active low device.

V+

4.

PB1 PB2

PB3 PB4

Post Presentation Self Assessment Activity

How may ways are there to wire a push button as an active low device?

V+

PB1

V+

V+

PB2V+

PB3

V+

PB4

Post Presentation Self Assessment Activity

7.

2 ways – PB1 and PB4

How may ways are there to wire a push button as an active high device?

8.

2 ways – PB2 and PB3

A. Wire a normally open push button as an;

V+

PB1

V+

V+

PB2

V+

PB3

V+

PB4

Post Presentation Self Assessment Activity

9.

(a) Active low push button.(actually draw this

circuit to make sure you can do it.)

(b) Active high push button.(actually draw this

circuit to make sure you can do it.)

(c) Active high push button.(actually draw this

circuit to make sure you can do it.)

B. Wire a normally closed push button as an;

(d) Active high push button.(actually draw this

circuit to make sure you can do it.)

Can a normally

V+

PB1

V+

V+

PB2

V+

PB3

V+

PB4

Post Presentation Self Assessment Activity

10.

(a) open push button be used to make an active low output

device?

YES

(b) open push button be used to make an active high output

device?

YES

(c) closed push button be used to make an active low output

device?

YES

(d) closed push button be used to make an active high output

device?

YES

End of Presentation