Circuit Finder

16 Stage Bi-Directional LED Sequencer

Published on 2011-01-18 07:27:47

The bi-directional sequencer uses a 4 bit binary up/down counter (CD4516) and two "1 of 8 line decoders" (74HC138 or 74HCT138) to generate the popular "Night Rider" display. A Schmitt Trigger oscillator provides the clock signal for the counter and the rate can be adjusted with the 500K pot.

10 Channel LED Sequencer

Published on 2011-01-18 07:26:38

10 Channel LED Sequencer

18 Stage LED Sequencer

Published on 2011-01-18 07:25:00

When power is applied, the 15K resistor and 10uF cap at pin 15 will reset the counters to the zero count where pin 3 is at +12 and all other outputs are at zero. The 2 diodes (1n914) and 15 resistor form a AND gate so the clock pulse will be passed to the right side counter when the sequence starts.