Method and apparatus for measuring elapsed time between an initiating event and a dependent event

• US 4,449,830 A
• Filed: 07/31/1981
• Issued: 05/22/1984
• Est. Priority Date: 07/31/1981
• Status: Expired due to Fees

• Current Assignee: Combustion Engineering Incorporated (ABB Limited)
• Original Assignee: Combustion Engineering Incorporated (ABB Limited)
• Inventors: Bulgier, Lawrence W.
• Primary Examiner(s): Roskoski, Bernard
• Application Number:
  US06/288,842
• Time in Patent Office: 1,026 Days
• Field of Search: 368/46, 368/52, 368/59, 368/60, 368/119, 368/107, 368/108, 368/113, 368/121, 375/106, 375/110, 375/114, 179/2 TC
• US Class Current: 368/119
• CPC Class Codes: G04F 10/00 Apparatus for measuring unknown time intervals by electric means

Abstract

A timer system (10,110,210) of two or more timers (10,110,210) measures the response time between an initiating event and a dependent event. The initiating and dependent events may be physically separated or electrically isolated. The timer system (10,110,210) permits recording of associated initiating and dependent events for a response time test followed by the recording of additional associated initiating and dependent events for additional response time tests while the timers remain separated. Thus, the timer system (10,110,210) permits serial recording of information for a large number of response time tests. The timers (10,110,210) may be identical. The timers (10,110,210) are interconnected and synchronized, then disconnected and separated to record the time of occurrence of the physically separated or electrically isolated events. The timers (10,110,210) are then again interconnected for a simultaneous recording of the elapsed time on each timer. A correction is made in the recorded time of occurrence of the events on all but one timer (10,110,210) to compensate for the differences in elapsed time. The response time between initiating and dependent events is then calculated to a common time base. The timer system (10,110,210) can also be used to record analog signals (68,72,74,168,172,174) to a common time base or as a conventional timer (10,110,210) to time an event from start (60) to finish (62).

Claims

1. A timing system for determining the time interval between the occurrence of an initiating event and a dependent event, comprising:

a first timing means comprising, a first power supply having a signal ground;

a first oscillator for generating periodic clock pulses of a known frequency;

a first resettable clock register for counting clock pulses generated by said first oscillator, powered by said first power supply;

means for resetting said first clock register;

a first snapshot register;

means for initiating the transfer of the number of counted clock pulses stored in said first clock register to said first snapshot register;

means for transferring the number of counted clock pulses stored in said first clock register to said first snapshot register;

means for displaying said number of counted clock pulses stored in said first snapshot register;

a second timing means comprising, a second power supply having a signal ground;

a second oscillator for generating periodic clock pulses of said known frequency, powered by said second power supply, a second resettable clock register for counting clock pulses generated by said second oscillator;

means for resetting said second clock register;

a second snapshot register;

means for intiating the transfer of the number of counted clock pulses stored in said second clock register to said second snapshot register;

means for transferring the number of counted clock pulses stored in said second clock register to said second snapshot register;

means for displaying said number of counted clock pulses stored in said second snapshot register;

means for interconnecting said signal ground of said first power supply and said signal ground of said second power supply;

means for interconnecting said means for resetting said first clock register and said means for resetting said second clock register; and

means for interconnecting said means for intiating the transfer of the number of counted clock pulses stored in said first clock register to said first snapshot register and said means for intiating the transfer of the number of counted clock pulses stored in said second clock register to said second snapshot register, whereby said first and second timing means are adapted to be interconnected for synchronization, capable of being separated for timing and adapted to be interconnected again subsequent to the timing to determine an absolute time.

2. The timing system as in claim 1:

wherein said means for displaying said number of counted clock pulses stored in said first snapshot register includes a binary-to-decimal converter interposed between said first snapshot register and said display means.

3. The timing system as in claim 2:

wherein said means for displaying said number of counted clock pulses stored in said first snapshot register includes a printer.

4. The timing system as in claim 1:

wherein said means for displaying said number of counted clock pulses stored in said second snapshot register includes a binary-to-decmial converter interposed between said second snapshot register and said display means.

5. The timing system as in claim 4:

wherein said means for displaying said number of counted clock pulses stored in said second snapshot register includes a printer.

6. The timing system as in claim 1:

wherein said means for resetting said first clock register is a pushbutton switch.

7. The timing system as in claim 1:

wherein said means for initiating the transfer of the number of counted clock pulses stored in said first clock register to said first snapshot register is a pushbutton switch.

8. A method of determining the time interval between an initiating event and a dependent event of a series of two or more associated, physically separated or electrically isolated events, which comprises the steps of:

interconnecting a first and a second timer a first time;

synchronizing said first and said second timers while interconnected;

disconnecting said first and said second timers;

recording the elapsed time from synchronization to each of the initiating event and dependent event of the series of two or more associated events, one on each of said first and said second timers;

interconnecting said first and said second timers a second time; and

measuring simultaneously the elapsed time on said first and said second timers, so that the elapsed time of the timer with the larger elapsed time may be taken as absolute time, the event times on the timer with the smaller elapsed time adjusted and the response times calculated.