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4987 Views 1 Reply Latest reply: May 29, 2014 4:52 PM by baycollie RSS
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May 23, 2014 3:27 PM

Pulse Generator Circuit

Good day!


I need a pulse generator and found this circuit on a website. But if I do try to make it, it won't work as indicated.

Any idea as to why that is? What part values should be changed so that we could a get 1-2 Hz pulse? Or if not, how about a tried and tested schematic for a pulse generator that works. And if it still won't work, is something like this available for purchase?



  • baycollie Novice 9 posts since
    May 29, 2014
    Currently Being Moderated
    May 29, 2014 4:52 PM (in response to JohnDavis)
    Is this the way the circuit should work ?

        It looks like N1is the rc ocsillator circuit to clock the 4017 ring counter. It goes to the clock input (pin 13) of the 4017 thru nand gate N3. The other input to N3 is from N2. N2's output is low from pull up resistor on it's inputs. A low on either input of N3 will give a high output, so the ring counter is not being clocked. The outputs of the ring counter go High, one at a time, in sequence as the counter is clocked. If the 4017 is in a reset state, then only output Q0 is High (LED on). A low has to be applied to N2 inputs for the clock to start the counter, by pressing a switch that is attached to a counter output that is low. Then N2's output goes high, a reset pulse is sent to the counter. The clock should clock the counter while the switch is held down and as many clock puses should appear at the output of N3 as needed to cycle the counter to a high at the that switch. I.E. pressing switch 8 should give 8 pulses if the switch is held down.  When that happens, N2 should go low again, stopping the clock. Pressing a different switch (attached to a low counter output) should start the sequence again.

       I don't know if this is the behavior you are trying to achieve by using this circuit. ??

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