Re: 4017 Counter skips under load



jcargile2001@xxxxxxxxx wrote:

Sorry, I mistyped. The clock pulse coming into the 4017 from the PC
parallel port is 25 ms in length. The counter then activates the next
relay in sequence and the output stays active for 10-20 seconds before
moving on to the next firing cue. I'll post a printout of the circuit
design when I get home in a couple hours. I'm using a pretty good
sized power supply, and I've tried other power sources as well with
the same results. Should I be doing some sort of decoupling where the
power enters the board as well? I noticed that the parallel port
interface card that I'm using has some sort of diode/cap combination
where the power enters the board. Would this help even things out
further?


The printer port puts out TTL compatible voltage levels and will not reliably clock a 4017 powered from 12V. The 4017 will have problems driving the typical relay coil directly. You should forget about completing this project on time and ask your teacher for an extension. You have a lot more homework and circuit modifications to perform before you get close to finishing it.

.

Relevant Pages

  • Re: 4017 Counter skips under load
    ... But when I try to operate the circuit under load ... skips the loaded relay and moves right to the next output. ... Think "star grounding" and power decoupling. ... lead from the parallel port as short as possible. ...
    (sci.electronics.design)
  • Re: 4017 Counter skips under load
    ... But when I try to operate the circuit under load ... skips the loaded relay and moves right to the next output. ... Think "star grounding" and power decoupling. ... lead from the parallel port as short as possible. ...
    (sci.electronics.design)
  • Re: 4017 Counter skips under load
    ... parallel port is 25 ms in length. ... sized power supply, and I've tried other power sources as well with ... driving the typical relay coil directly. ... The clock pulses generated ...
    (sci.electronics.design)
  • Re: 4017 Counter skips under load
    ... parallel port is 25 ms in length. ... sized power supply, and I've tried other power sources as well with ... driving the typical relay coil directly. ... The clock pulses generated ...
    (sci.electronics.design)
  • Re: NOW: Fuel Pump Install...WAS: EGR VALVE! 87 Golf
    ... This eliminates faulty wiring and insufficient power and then I can ... I usually use a jumper wire after I remove the relay to supply power to the ... Then at the pump connect ... lead of the test light to. ...
    (rec.autos.makers.vw.watercooled)
Loading