×

Engine test and display apparatus

  • US 4,125,894 A
  • Filed: 05/18/1977
  • Issued: 11/14/1978
  • Est. Priority Date: 12/16/1975
  • Status: Expired due to Term
First Claim
Patent Images

1. Improved apparatus for measuring the dwell of an ignition system of an internal combustion engine having a predetermined number of cylinders and fuel ignitors, said ignition system comprising a switch periodically opened and closed in synchronism with the rotation of the engine in order to create time-spaced ignition pulses for firing the ignitors, the switch being closed for a dwell time period and being open for a firing time period in order to create such ignition pulse, said apparatus comprising:

  • clock means for producing clock pulses at a predetermined rate;

    first counter means for counting the clock pulses;

    second counter means for counting the clock pulses;

    first gate means for transmitting clock pulses to the first counter means in response to a first one of the ignition pulses and for preventing the transmission of clock pulses to the first counter means in response to a second one of the ignition pulses;

    second gate means for transmitting clock pulses to the second counter means only during the duration of one or more dwell time periods which occur between the first ignition pulse and the second ignition pulse;

    processor means for producing a digital dwell signal having a value proportional to the count of the second counter means divided by the count of the first counter means; and

    display means for displaying a swell number having a value proportional to the value of the dwell signal.

View all claims
  • 5 Assignments
Timeline View
Assignment View
    ×
    ×