4. 2 Digit Object/Product counter
Object counters or product counters are important
applications used in industries, shopping malls, etc.
They count objects or products automatically and so
reduce human efforts. In this tutorial we are going to
design a simple object counter circuit without using
any microcontroller.
5. Components
1. LM358 IC - 1
2. 555 timer IC -1
3. Voltage Regulator 7805 -1
4. 150 Ohm - 2
5. CD4033 -2
6. 10K resistor -2
7. 100K resistor -1
8. 10K POT -1
9. 220uF capacitor -1
10. IR sensors-1
11. Bread board-1
12. 9 Volt Battery -1
13. Battery Connector-1
14. LED -2
7. EXPLAINATION
In this circuit we have used a comparator
(IC LM358) and IR transmitter and
receiver pair for detecting an object.
And then we have used a 555 timer IC to
generate a pulse for triggering the seven
segment decoder (CD4033) and two
common cathode seven segment display
units are connected with 7 segment
decoder IC.
8. EXPLAINATION
555 timer IC is configured in mono-
stable mode for generating pulse.
A LM7805 Voltage regulator is used
for providing constant 5 volt power
supply for the circuit.
And a 9 volt battery used for powering
the whole circuit.
9. WORKING
In this circuit we detects object by using IR
sensor and comparator and then we applied
output of comparator to mono-stable multi-
vibrator. This mono-stable multi-vibrator
generates a pulse of fix time period which can
be set by using given formula.
T=1.1RC
11. WORKING
In this circuit we have selected R1 is 10K and
C1After getting a pulse from 555 timer we
applied this to clock pin of 7 segment decoder
(U4) and then carry out signal (pin 5) to clock pin
of another 7segment decoder (U3). After getting
pulse from 555 timer 7 segment counter changes
number value of segment display.
12. WORKING
when number counting reaches at 10 in
U4 decoder then it sends carry out signal
or pulse to seconds 7segment decoder
(U3) and then second display changes his
number value. And this process repeats
again. This object counter circuit can
count 00-99.