People / Object counter circuit have a wide variety of applications in
Banks, Hospitals, factories etc. This project focuses on building an effective
counter using IR as a sensing element and capable of counting from 0 to 99.
This project uses Two simple IC’s ( IC 555 & IC 4026 ) with IR transmitter
and Receiver to detect the incoming people/object.
Counters with
directional detection are useful for counting of objects moving along a
predefined path. These may find application as visitor counters and also for
counting of objects. Here we present a simple circuit that counts the number of
persons or the objects entering the premises. The counter section consists of
two IR LEDs & IR receiver as detectors. The movement of objects including
the direction of their movement is detected by the arrangement of the IR LED
and IR Receiver detector pairs. The IR Receiver of each pair is mounted
opposite to its corresponding IR LED fall directly on the IR Receiver detect.
Description
To understand its
working how we can interface 4026 with 7 segment display, first have
to look on its pin diagram -
Now let us
understand the working of individual pins-
1. Pin 1 or clock
pin- It receives clock signals, and at every positive clock and counter
advances one by one. You can provide clock with the switch, 555 timer or with
the help of logic gates. In short high pulse on this input increments the
counter.
2. Pin 2 or disable
clock (clk inhibit) pin- 4026 counter advances one by one by receiving positive
pulse at this time for this clock inhibit pin should be grounded. If it is
connected to supply than counter advancement will be inhibited means there will
be no meaning of clock pulse.
3. Pin 3 or enable
display (En in) pin- It enable the 7 segment display to display the numeric
value. It should be kept high for enabling the display. Mean output goes high
when only when display enable is high.
4. Pin 4 or enable
out- It Enables the carry out pin. In our circuit we have left this pin
unconnected.
5. Pin 5 or divide
by 10 output- It is used to complete one cycle for every 10 clock input cycle
and it also used to cascade more IC's.
6.Pin 6, pin7 and
Pin9 to pin 13 - These are 7 decoded output from a to g used to illuminates the
corresponding segment of 7 segment display to display the digit from 0 to 9.
7. Pin 14 or not 2
output (UNGATED "C" SEGMENT) signals- They are not gated by the
Display clock and therefore are available continuously. This feature is a
requirement in implementation of certain divider function such a as divide by
60 and divide by 12.
8. Pin 15 or Reset
pin- It is used to reset the counter. When it receives high it clears the
counter and counting again starts from zero. One important thing reset pin
should again made low to start the counter once again.
9. Pin 8 or ground
pin and Pin 16 known or Vdd it should be connected to power supply.
