was requested by Mr.Joe, one of the keen followers of this blog. The circuit
initially was intended to be used for generating LED strobe light effects and
was asked to be modified such that it could be used as an LED sequencer as well
as a blinker. The change over would be implemented via a toggle switch.
and competent this device is. Basically the IC a Johnson’s decade counter/divide
by 10 IC, fundamentally used in applications where sequencing positive output
signals are required or desired.
orderly shifting of the outputs take place in response to a clock pulse that
needs to be applied at the clock input pin #14 of the IC.
responds and pushes its output’s positive from the existing pin out to the next
pin out in the order.
providing the above clock pulses to the IC 4017. VR1 may be adjuted for
determining or fixing the speed of the sequencing.
specific order which makes the LEDs look like as if they are running or chasing
during the operations.
effect, the diodes would not be required, however as per the present ask the
diodes become important and allows the circuit to be used as a blinker also,
depending upon the position of the switch S1.
like a light chaser and produces the normal chasing effect over the LEDs which
start illuminating in sequence from top to the bottom, repeating the operations
as long as the circuit remains powered.
the oscillator are shifted into the input of the transistor T1, which instantly
stats to pulsate all the LEDs together in response to the received clocks from
ordinary light chaser circuit with an additional feature through which the
circuit now is also able to function as a LED flasher.
gates from the IC 4049 either to the positive or the negative of the supply.
The supply pins of the IC 4049 also need to be connected to the relevant supply
rails of the circuit, kindly refer to the datasheet of the IC.
chaser cum flaher circuit:
R4 = 100k
ch_client = “swagatam”;
ch_width = 550;
ch_height = 90;
ch_type = “mpu”;
ch_sid = “Chitika Default”;
ch_backfill = 1;
ch_color_site_link = “#3D76CC”;
ch_color_title = “#3D76CC”;
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All LEDs = RED, 5mm or as per choice,