Temperature Controller
R. Theagarajan. ME., MSc., PhD Rtd. Professor in Engineering email: rtheagarajan@yahoo.com rtrajan59@gmail.com
Temperature Controller – Basic requirements
Temperature Controller – Basic requirements Display devices to show temperature Seven segment display - Six I/O lines LCD display - Ten I/O lines
Temperature Controller – Basic requirements Display devices to show temperature Seven segment display - Six I/O lines LCD display - Ten I/O lines Input devices to set temperature limits Key pad, TWS - Four I/O lines
Temperature Controller – Basic requirements Display devices to show temperature Seven segment display - Six I/O lines LCD display - Ten I/O lines Input devices to set temperature limits Key pad, TWS - Four I/O lines Output indicators - Three I/O lines High, Red color LED Normal, Green color LED Low, Yellow color LED
Temperature Controller – Basic requirements Display devices to show temperature Seven segment display - Six I/O lines LCD display - Ten I/O lines Input devices to set temperature limits Key pad, TWS - Four I/O lines Output indicators - Three I/O lines High, Red color LED Normal, Green color LED Low, Yellow color LED Output Alarm, Buzzer One I/O line
Temperature Controller – Basic requirements Input from the sensor unit Thermistor - One I/O line Thermocouple - One I/O line
Temperature Controller – Basic requirements Input from the sensor unit Thermistor - One I/O line Thermocouple - One I/O line ADC to read analog input, Convert to digital to feed it to microcontroller Eight I/O lines
Temperature Controller – Basic requirements Input from the sensor unit Thermistor - One I/O line Thermocouple - One I/O line ADC to read analog input, Convert to digital to feed it to microcontroller Eight I/O lines If ADC is multi-channel, then other lines are required Three I/O lines to select the channel One I/O line for start of conversion One I/O line for End of conversion One I/O line to enable the output
Temperature Controller – Basic requirements Number of Input pins required Thumb wheel switch - Four input lines Analog input to ADC - One I/O line Number of output pins required Seven segment display - 6 lines Output indicators - 3 lines Alarm - one line ADC output - eight lines Start and Output enables lines - 2 Total number of lines required are 24
Vdc
ADC
Vdc
Osc
ADC
R1
Vdc
Clock
C1
ADC
R1
Vdc
Clock
C1
ADC
R1
Vdc
Clock
ADC
C1 V.ref
VR
R1
Vdc
Clock
ADC
C1 V.ref
+12
VR R2
R3
R1
Vdc
Clock
ADC
C1 V.ref
+12
A2 A1 A0
VR R2
R3
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
A2 A1 A0
VR R2
R3
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
A2 A1 A0
VR R2
R3
ALE
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR R2
R3
ALE
+5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR R2
R3
ALE
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR R2
R3
ALE
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR R2
R3
ALE
C
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR R2
R3
ALE
PA
C
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
ALE Latch
R2
R3
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
ALE Latch
R2
R3
7447
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
ALE Latch
R2
R3
7447
R.pad
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
ALE
PB
R2
R3
Latch
7447
R.pad
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
C
TWS
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
OE +5 V
R1
Vdc
Buffer
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
PC
C
TWS
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
Buffer
Buffer
TWS
TWS
Latch
7447
R.pad
Latch
7447
R.pad
PC
C
ALE
PB
R2
R3 +5
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
Buffer
Buffer
Buffer
Buffer
TWS
TWS
TWS
TWS
Latch
7447
R.pad
Latch
7447
R.pad
PC
C
ALE
PB
R2
R3 +5
OE +5 V
R1
Vdc
D-bus
Clock
ADC
C1 V.ref
+12
SOC
A2 A1 A0
VR
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
74138
OE +5 V
R1
Vdc
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
VR
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
74138
Enable OE +5 V
R1
Vdc
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
VR
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
74138
Enable OE +5 V
R1
Vdc
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
VR
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
74138 Enable Enable OE +5 V
R1
Vdc
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
VR
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
74138 Enable Enable OE +5 V
R1
Vdc
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
VR
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
74138 Enable Enable OE +5 V Vdc
R1
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
VR
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
74138 Enable Enable OE +5 V Vdc
R1
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
7805
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
Latch
7447
R.pad
R2
R3 +5
+5
-
74138
+
Enable Enable
K OE +5 V Vdc
R1
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
7805
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
7475
7447
R.pad
R2
R3 +5
+5
-
-
74138
+
+
Enable LM335
K
Enable
OE +5 V Vdc
R1
SOC
D-bus
Clock
ADC
C1 V.ref
+12
PC
A2 A1 A0
7805
PA
Buffer
Buffer
Buffer
Buffer
5
1
6
2
PC
ď C
Low Limit
High Limit
ALE
PB
Latch
7447
R.pad
7475
7447
R.pad
R2
R3 +5
Avoid Plastics Plant a Tree Let us take care of our earth for future generation