+ Reply to Thread
Page 6 of 6 FirstFirst 1 2 3 4 5 6
Results 51 to 52 of 52

Thread: Pondering simplicity: analog o2 monitoring?

  1. #51
    RBW Member cstmwrks is a jewel in the rough cstmwrks is a jewel in the rough cstmwrks is a jewel in the rough cstmwrks is a jewel in the rough cstmwrks is a jewel in the rough cstmwrks is a jewel in the rough cstmwrks is a jewel in the rough cstmwrks's Avatar
    Join Date
    Sep 2006
    Location
    Boise Idaho
    Posts
    286
    Arctic Lung, MR101, LARV clone

    Re: Pondering simplicity: analog o2 monitoring?

    Quote Originally Posted by heyydude  View Original Post
    In the Horseshoe Board of the Mark 15, there is a 530 Ω Resistor in-line with each sensor (the Mark 15 was designed to use BioMarine Sensors, which were made individually out of stainless steel, plastic, and other parts). Later, the Mark 16 was modified to have a 2k Ω resistor in line with the sensors (R-10 types made by Teledyne and AI).

    Kevin.
    Hi Kevin,
    OK "A" is what you described, correct? What about the use of a 10K resistor across the leads in "B" like the El Cheapo panel meter and PP02.com's kits? I'm still digging through old design notes but have not run across the reason for the 10K across the leads. Vague memory says the cell needed the load.

    Would that still be the case if one ever found an old analog meter of the right range and connected it to a modern R-22?
    ** I found an old spec sheet on the R-22 last night and it said a 10K load was required. **
    analog2.jpg
    Last edited by cstmwrks; 21st July 2016 at 04:58. Reason: updated info

  2. #52
    King of the Geeks
    heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude has a reputation beyond repute heyydude's Avatar
    Join Date
    May 2005
    Location
    Addison, Pennsylvania
    Posts
    1,397
    HAMMERHEAD!

    Re: Pondering simplicity: analog o2 monitoring?

    A is correct.

    The 10k Ω resistor is generally used at the electronics, and is called out in the datasheet of the R22 I believe.

    In the Analog sets (Mark 15), the O2 Sensor signal went through an LM101-AH Operational Amplifier which boosted the signal so the rest of the electronics could deal with it.

    In digital circuits, we generally feed that either through an Op-Amp to the CPU internal A/D, or through a separate A/D converter then to the CPU.

    Bottom line for what you're doing is it looks like you have it correct.

    Kevin.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts