Indicator systems

• US 3,217,144 A
• Filed: 08/06/1962
• Issued: 11/09/1965
• Est. Priority Date: 08/06/1962
• Status: Expired due to Term

• Current Assignee: Howard D. Hinnah
• Original Assignee: Howard D. Hinnah
• Inventors: Hinnah, Howard D.
• Application Number:
  US04/214,927
• Time in Patent Office: 1,191 Days
• US Class Current: 377/25
• CPC Class Codes: G01K 7/32 using change of resonant frequency of a crystal

Claims

1. MEANS FOR PRODUCING A DIGITAL SIGNAL INDICATIVE OF THE STATE OF A CONDITION, RELATIVE TO A REFERENCE STATE COMPRISING, (A) A VARIABLE FREQUENCY OSCILLATOR SENSITIVE TO SAID CONDITION TO OSCILLATE AT FREQUENCIES INDICATIVE OF THE STATE OF SAID CONDITION INCLUDING A FIRST FREQUENCY WHEN SAID CONDITION IS AT ONE EXTREME STATE IN SAID RANGE AND A SECOND FREQUENCY WHEN SAID CONDITION IS AT THE OTHER EXTREME STATE IN THE RANGE, (B) A FIXED FREQUENCY OSCILLATOR WHOSE FREQUENCY IS FIXED SUCH THAT THE DIFFERENCE BETWEEN SAID FIRST AND SECOND FREQUENCIES IS TO THE DIFFERENCE BETWEEN THE FREQUENCY OF SAID FIXED FREQUENCY OSCILLATOR AND SAID SECOND FREQUENCY AS THE DIFFERENCE BETWEEN SAID FIRST AND SECOND STATES OF SAID CONDITION IS TO THE DIFFERENCE BETWEEN SAID REFERENCE STATE AND SAID SECOND STATE OF SAID CONDITION,