Instructables

Is there a simple IC or circuit available that can do these kind of pulses?

I need a circuit that will give just a few pulses..... starting with a few seconds of "ZERO"...a long "one"...  Then three quick pulses.... then end with a constant "ONE" .  I have tried using a binary counter circuit and led's, but my design abilities are somewhat lacking.  I don't know how to use microcontrollers so that won't help.  I was hoping for some kind of IC that has input pins that can be grounded or diodes attached.  Then the IC would scan those parallel pins and send out the serial pulses as described.  I need this  to activate another circuit at work for my boss. I am good at building electronic circuits but not so great at designing them.  Thanks in advance for your help.


You could try using 4017 counters, cascading several if necessary. These have 10 outputs each which individually go high as clock pulses are applied to the clock input. Any number could be cascaded. The exact circuit could be found on the web, or determined from reading the datasheet if you are familiar with how logic circuits work and the terminology. The clock frequency would determine the smallest time interval. If the output must go high for several clocks, the outputs need to be OR'd together with diodes. For the spans of time where the output must be low, the corresponding outputs would be left unconnected.
+1
Hmm, one way of doing it would be to use an off-the-shelf kit - I built a fixed basis flasher like that from a light chaser.
AndyGadget3 years ago
 
Yep, easily do-able using either parallel in, serial out (PISO) shift registers, a demultiplexer running from a binary counter or a binary counter driving a ROM.

To decide which is the best way, you'll need to tell us the exact timing sequence required, how it needs to be triggered and how it needs to be reset.
rickharris3 years ago
http://www.picaxe.com

Picaxe 08 and minimal components - essentially 1 x 10K resistor to hold programming pjn low.

programme - assumes output from output 1 (leg 6)
Assumes positive trigger on pin 3

Start:
If pin3=0 then start, (check pin 3 for trigger)

High 1. (turns output on - High)
pause 2000, (waits for 2 seconds)
Low 8, (turns output off - low)

High 1
pause 500, (wait for 1/2 sec)
Low 1
pause 500, (wait 1/2 sec between pulses)

High 1
pause 500, (wait for 1/2 sec)
Low 1
pause 500

High 1
pause 500, (wait for 1/2 sec)
Low 1
pause 500

High 1. (turns output on - High)
pause 2000, (waits for 2 seconds)
Low 8, (turns output off - low)

end ,(if you want it to stop now. - or goto start if you want it to repeat)

You may need to do a little reading in the FREE PDF manuals to see about interfacing, Down loading the programme with their FREE programme editor. But essentially as you describe your problem that is an answer.