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  1. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Oct 17 an error in earlier work this year has been found. last spring , april 18 & 29 were posted circuits showing the 16F506 being used as a signal source for the 12F508. the idea is a good one. the error was with the ADC part of that uC. by the scan posted here today can be read that...
  2. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Sept 25 foto of new side panel and the old one. the 6" x 3" bread-board shown on the new panel holds the A/D circuitry. i.e. the input is the flywheel timing signal sine waves. and its output goes to the opto-isolator chip. and then its output pulse passes onto the CDI circuit...
  3. bob weir

    Digital programmable CDI ignition for 2-stroke engines

  4. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    sept 1 ....................the attached image below followed the one above by increasing the idle. just rotate a screw on the carb to adjust the engine idle speed up or down the Hz reads 35 for RPMs = 2100. ..............by the graph of 'deg-advance vas RPM' you can see that 2100 is at the...
  5. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    sept 1 ........... i think a warning is in order for these posts you have been faithfully following. something like : 'believe what you read and see at your own risk'. or something to remind you that 'to err is human' . or another way to spin it all is that what we believe to be true is...
  6. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    aug 30 ................. in regards to the posting yesterday aug 29 with its scope screen shots ... for those of you wondering where the CH 3 pulse with 200uS width comes from ... it comes from the CH 2 pulse. after its passed thru the C16-R17 differentiator. so a pulse of about .020 sec of...
  7. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    aug 29 ............... this post concerns a big timing error if the 2012 CDI design is not set up right. there are 4 jumpers on that circuit. remember the circuit can make a spark using its own on-board pulser signal. or use a pulse from the outside world to make a spark. this 2'd case is...
  8. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    . aug 26 engine RPM at idle factory spec' ... see it there in the box ... bottom line. this information is good to have. when the engine was running 2 weeks ago the scope was not used. an oversight. it is now important to know what is the upper limit in RPM the engine will idle at with...
  9. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    aug 24 .............. lets look at questions 3. , 4. , 5. and 8. of the aug 7 post. 3. not using the cursors , just eyeball the screen. the 70 to 10 horiz. LE distance is about 4.2 units. ............. and the timebase is 2.00ms ...... so the delta-t is 4.2x2 = .008 sec...
  10. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Aug 21 via see the BY value the -10 deg pulse triggers 'on' at about -2.2 volts and 'off' again then too note that these 2 pulses have different voltage-trigger values and their widths are not the same either as the fct. gen. output signal Vp amplitude is increased from 0.5 to 1.0 then...
  11. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Aug 21 here is the same screen image for the -70 deg pulse in black and white. to see how to edit the scope settings from color to b/w watch this video
  12. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Aug 21 lets look at question 2 of the aug 7 post and learn the voltage levels of the sinewave that trigger the -70 and -10 deg pulses. by the screen above and BY data in upper left window you can see the -70 deg pulse triggers 'on' when the sinewave voltage has risen to 1.00 V. and...
  13. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    aug 8 good news. the 225 engine runs. using the CDI board for the spark. and the -10 deg signal from the flywheel. it runs nicely. but just at idle. and i'm happy with that much the carburator was ultrasonically cleaned and reassembled. then placed back on the engine. next the gas line...
  14. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    aug 7 the circuit posted aug 5 was tested with a fct. gen. and scope. here is a screen shot from that effort. first impression is that the 2 circuits work ok operating in parallel to check your understanding here are some questions. often the steps that lead to success later are small...
  15. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    the circuit is nearly all bread-boarded. then it will be current - tested at +5V. and +12V for the opto. and if the ma numbers both look good the fct. gen sine wave will be applied. and all 4 channels of the Rigol 1054 scope used to see what the circuit signals look like. this is the...
  16. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    no , the new design signals-board circuit is not ready yet. so the old 2-Q circuit that only works on the -10 deg sine lobe was used with the CDI board to fire the spark plug. this was to test run the engine and hear how it sounds. another unexpected problem has arisen. the 225 engine does...
  17. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    july 31 the above 3 scan-images show the state of this CDI ignition project as of today already you've seen some of the signals circuits. individually they work ok. my efforts now are to combine them onto one board. with the uC , the new 7414 , 7432 and opto-isolator and apply the input signal...
  18. bob weir

    Digital programmable CDI ignition for 2-stroke engines

  19. bob weir

    Digital programmable CDI ignition for 2-stroke engines

  20. bob weir

    Digital programmable CDI ignition for 2-stroke engines

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