board game counter - analog
DESCRIPTION
Random Number Generator Analog Design - Demo Board Game Counter - Analog Random Number Generator Analog Design - Demo Digital Electronics TM 1.2 Introduction to Analog This presentation will Review the Random Number Generator block diagram. Review the circuit design of the analog section of the Random Number Generator. 2 Project Lead The Way, Inc. Copyright 2009TRANSCRIPT
Understanding Analog DesignThe Random Number Generator
© 2014 Project Lead The Way, Inc.Digital Electronics
Random Number GeneratorAnalog Design - Demo
2
This presentation will• Review the Random Number Generator block
diagram.
• Review the circuit design of the analog section of the Random Number Generator.
2
Random Number Generator Block Diagram
3
0 0 0 1 1 1
0 1 1 0 0 1
1 0 1 0 1 0
1 2 3 4 5 6
AnalogSection
SequentialLogic
Section
CombinationalLogic
Section
The Analog Section produces a dampened square wave that “rolls” the count and slowly stops.
On every pulse of the clock, the Sequential Logic Section increments a binary count from 1 to 6, then repeats.
The Combinational Logic Section encodes the binary count into the die’s seven dots.
CLOCK
L1L2L3L4L5L6L7
A
B
C
4
AnalogSection
CLOCKCombinational
LogicSection
The Analog Section produces a dampened square wave that “rolls” the count and slowly stops.
On every pulse of the clock, the Sequential Logic Section increments a binary count from 1 to 6, then repeats.
The Combinational Logic Section encodes the binary count into the die’s seven dots.
L1L2L3L4L5L6L7
SequentialLogic
Section
A
B
C
Random Number Generator Block Diagram
5
Schematic Diagram
CLOCK
Random Number Generator Analog Section
A Simplified Version
6
• When the push button switch is pressed, the 100uf capacitor (C1) will quickly charge to 5 volts through the 1.2 k resistor (R8).
• As long as the push button switch remains pressed, top end of the 10 k resistor (R9) will be held at 5volts. This results in a simplified version that is equivalent to a standard 555 time oscillator.
Actual Version Simplified Version
Analysis of Simplified Version
7
nF 470 C k 18 R k 10 R BA
mSec 982.14T
nF 470 k 182k 10 693.0T
C R2R 693.0T BA
Hz 66.74 ƒmSec .T
ƒ
9821411
Period:
Frequency:
RAA
RB
C
Simulation of Simplified Version
8
VOUT
VC
Simplified Version – Timing Analysis
9
mSec 15T
Hz 66.66 ƒmSec
ƒ
Tƒ
151
1
Period:
Frequency:
VOUT
VC
The Actual Version
10
• When the push button switch is pressed and held, the actual analog section of the Board Game Counter performs like a standard 555 time oscillator. However, for the Board Game Counter to operate correctly, the oscillation must slow and eventually stop.
• This is where the 100uF capacitor (C1) and the 1.2 k resistor (R8) play a role.
Actual Version Simplified Version
Simulation of Actual Version
11
VOUT
VCVLimit
PushButton Pressed
PushButton Released
Actual Version – Timing Analysis
• When the push button is pressed, the 555 Timer produces a 66 Hz square wave.
• Once the push button is released, the frequency gradually decreases (period increases).
• Eventually the oscillation will stop.
12
VOUT
VCVLimit
PushButton Pressed
PushButton Released
A CB
Timing Analysis at Time A
13
A
mSec 536.15T
Hz 64.36 ƒT
ƒ
1
Period:
Frequency:
Timing Analysis at Time B
14
B
mSec 50.27T
Hz 36.36 ƒT
ƒ
1
Period:
Frequency:
Timing Analysis at Time C
15
C
mSec 429.51T
Hz 19.44 ƒT
ƒ
1
Period:
Frequency:
16
SequentialLogic
Section
CombinationalLogic
Section
Analog Section
Discussed in a future lesson
Random Number Generator Analog Section