Ring
Counter Circuit Working Principle with Animation and Video
By
Jaseem Vp
Digital counters have several
applications in electronics circuits. Counters in digital electronics are
used at different situations. Here we are going to deliver the idea of
a Ring counter circuit, which is a register counter. Working animation and circuit simulation video of ring counter are also given along
with this article. A ring counter is formed by feeding the output of a shift
register to its own input.
The data pattern enclosed within the shift register will re-circulate as with
respect to the clock pulse. Ring counter is one of the shift register
applications. We have already posted Johnson counter circuit with animation. With little
modification on ring counter we can obtain Johnson counter circuit. A ring
counter has N states where ‘N’ is the number of flip-flops. So let’s discus
about digital counter circuit design (Ring counter) in detail with animation/ simulation.
Digital
counter schematic Circuit
Components
required for digital electronics counters
- Power
supply
- IC
7474 x 4
- LEDs
x 4
- Resistors
47kΩ x 4
- Clock
circuit
Ring
counter State/ truth table
Working of
ring counter circuit
- This
counter is a circulated shift register. Here a 4 bit shift register is
implemented with 7474 flip flops. This is a synchronous counter because
clock signal is common for all flip flops.
- The
‘Q’ output of first flip flop is directly fed to the ‘D’ input of
following flip flop unit.
- The
final ‘Q’ output from the last flip flop is connected to the ‘D’ input
of 1st unit; hence it is called as a circulating shift register.
- ‘Preset’
pin of 1st unit is connected to Vcc via a
switch (Push to OFF switch). Preset pin is used to set the output of a
flip flop to logical high (1) forcefully.
- The
‘Presets’ of other flip flops are directly coupled to Vcc in order to work properly because these pins are
active low logic pins (This connection is not shown in above circuit.
For simplicity it is removed). But don’t forget to connect it while you
are implementing practically.
- Similarly
‘Clear’ pins are also connected to Vcc due to
the above said reason.
- We
are already familiar with shift registers that for each clock pulse the
data will be shifted to next register (flip flop).
- Initially
all the outputs of flip flops are at low, to start ring counter you need
to set the output of first flip flop manually high.
- For
this purpose you just push the switch (SW2), then the output of first
flip flop goes high.
- This
output will be shifted to the next flip flop during the next clock pulse
and so on. At the same time the low output from last flip flop is
shifted to the input of 1st flip flop.
- Please
refer the animation and video for better understanding.
Ring
counter circuit animation
Ring
counter circuit simulation video
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