Kits
›
El contador de visitantes
RU
EN
ES
Contenido
Introduction
History: how light learned to count people
Lesson 0. Gates from transistors: for those who start from scratch
0.1. The idea: a transistor is a switch
0.2. Building
0.3. Check
Lesson 0 paste (Cmd+I)
Lesson 1. The beam and CD4011
1.1. Idea: how a shop counts people
1.2. Idea: the CMOS 4000 series
1.3. Idea: NAND for everything
1.4. Build
1.5. Check
Lesson 1 paste (Cmd+I)
Lesson 2. The F/F flip-flop
2.1. Idea: a counter is flip-flops that flip
2.2. Idea: flipping through exclusive OR
2.3. Idea: a NAND with three inputs
2.4. Build
2.5. Check
Lesson 2 paste (Cmd+I)
Lesson 3. The CD4029B counter
3.1. Idea: which bit to flip
3.2. Idea: controlling the counter
3.3. Idea: the bubbles on the TI drawing
3.4. Build
3.5. Check
Lesson 3 paste (Cmd+I)
Lesson 4. The CD4511B decoder
4.1. Idea: seven strokes
4.2. Idea: latch, blanking, lamp test
4.3. Idea: a switch on two transistors
4.4. Build
4.5. Check
Lesson 4 paste (Cmd+I)
Lesson 5. Direction
5.1. Idea: two beams one after another
5.2. Idea: remember the first
5.3. Idea: the clock is when both are blocked
5.4. Build
5.5. Check
Lesson 5 paste (Cmd+I)
Lesson 6. The visitor counter
6.1. Idea: two displays on the same beams
6.2. Idea: two digits — two counters
6.3. Idea: Reset holds
6.4. Build
6.5. Check
Lesson 6 paste (Cmd+I)
Summary
All the parts
Instructions in pictures
Lesson 6 in pictures
← Back to the lesson: Lesson 6. The visitor counter
6
The visitor counter
"inside" and "total in" displays
kh
HT-04
A
B
INSIDE
TOTAL IN
Q
Q
1×
CD4029
4×
3
CD4511
4×
4
∞
© 2026 Daniil Khanin · khanin.info · HT-04
54
CANVAS
1
Q
Q
1×
1×
Reset
Reset
RESET
2
CD4029
1×
3
14×
CD4029
PE
RESET
J4
GND
J1
GND
CI
GND
BD
GND
UD
IN
J2
GND
J3
GND
CLOCK
BOTH
Q4
U3
Q1
U0
CO
COU
Q2
U1
Q3
U2
3
CD4029
1×
3
14×
CD4029
PE
RESET
J4
GND
J1
GND
CI
COU
BD
GND
UD
IN
J2
GND
J3
GND
CLOCK
BOTH
Q4
T3
Q1
T0
CO
COT
Q2
T1
Q3
T2
4
CD4029
1×
3
14×
CD4029
PE
RESET
J4
GND
J1
GND
CI
OUT
BD
GND
UD
VCC
J2
GND
J3
GND
CLOCK
BOTH
Q4
V3
Q1
V0
CO
COV
Q2
V1
Q3
V2
© 2026 Daniil Khanin · khanin.info · HT-04
55
CANVAS …
5
CD4029
1×
3
14×
CD4029
PE
RESET
J4
GND
J1
GND
CI
COV
BD
GND
UD
VCC
J2
GND
J3
GND
CLOCK
BOTH
Q4
W3
Q1
W0
CO
COW
Q2
W1
Q3
W2
6
CD4511
1×
4
14×
CD4511
B
U1
C
U2
LT
VCC
BL
VCC
LE
GND
D
U3
A
U0
e
Ue
d
Ud
c
Uc
b
Ub
a
Ua
g
Ug
f
Uf
© 2026 Daniil Khanin · khanin.info · HT-04
56
CANVAS …
7
CD4511
1×
4
14×
CD4511
B
T1
C
T2
LT
VCC
BL
VCC
LE
GND
D
T3
A
T0
e
Te
d
Td
c
Tc
b
Tb
a
Ta
g
Tg
f
Tf
8
CD4511
1×
4
14×
CD4511
B
V1
C
V2
LT
VCC
BL
VCC
LE
GND
D
V3
A
V0
e
Ve
d
Vd
c
Vc
b
Vb
a
Va
g
Vg
f
Vf
9
CD4511
1×
4
14×
CD4511
B
W1
C
W2
LT
VCC
BL
VCC
LE
GND
D
W3
A
W0
e
We
d
Wd
c
Wc
b
Wb
a
Wa
g
Wg
f
Wf
10
Reset — press and let go: while pressed, the displays stay at 00
11
the lesson 4 display — Cmd+C, Cmd+V: legs a–g are already named
12
displays in pairs: tens on the left, units on the right; "inside" on top
© 2026 Daniil Khanin · khanin.info · HT-04
57
CANVAS …
13
7×
Segment LCD
Ta
a
Tb
b
Tc
c
Td
d
Te
e
Tf
f
Tg
g
14
7×
Segment LCD
Ua
a
Ub
b
Uc
c
Ud
d
Ue
e
Uf
f
Ug
g
15
7×
Segment LCD
Wa
a
Wb
b
Wc
c
Wd
d
We
e
Wf
f
Wg
g
16
7×
Segment LCD
Va
a
Vb
b
Vc
c
Vd
d
Ve
e
Vf
f
Vg
g
in
A
B
inside
total
out
A
B
inside
total
© 2026 Daniil Khanin · khanin.info · HT-04
58
← Back to the lesson
Lesson 6. The visitor counter