公开(公告)号：US3614667A

公开(公告)日：1971-10-19

申请号：US3614667D

申请日：1964-03-19

Applicant: ITEK CORP

Inventor： FLETCHER MARTIN W

IPC: H03B1/00 ,  H03B5/36 ,  H03J5/24 ,  H03C3/28

CPC classification number: H03J5/246 ,  H03B5/366 ,  H03B2200/0048 ,  H03B2200/0052 ,  H03B2200/0056 ,  H03B2201/0258

Abstract: 6. Apparatus for pulse modulating a crystal oscillator comprising: A TRANSISTOR AMPLIFIER; A PLURALITY OF PARALLEL FEEDBACK PATHS CONNECTED TO SAID AMPLIFIER, EACH SAID FEEDBACK PATH INCLUDING A CRYSTAL HAVING A DIFFERENT RESONANT FREQUENCY; SWITCH MEANS ASSOCIATED WITH EACH OF SAID FEEDBACK PATHS, EACH SAID SWITCH MEANS NORMALLY OPEN TO DISCONNECT EACH OF SAID FEEDBACK PATHS FROM SAID AMPLIFIER; MEANS FOR APPLYING A PULSE MODULATING SIGNAL TO AT LEAST THE BASE ELECTRODE OF ONE TRANSISTOR FORMING ONE STAGE OF SAID AMPLIFIER TO RENDER IT CONDUCTIVE; GAIN CONTROL MEANS CONNECTED TO THE STAGE OF SAID AMPLIFIER TO WHICH SAID-PULSE MODULATING SIGNAL IS APPLIED FOR PROVIDING MAXIMUM GAIN IN SAID AMPLIFIER WHEN SAID AMPLIFIER IS FIRST RENDERED CONDUCTIVE AND FOR DECREASING THIS GAIN THEREAFTER; AND MEANS FOR APPLYING SUCCESSIVE SWITCHING SIGNALS TO SAID SWITCH MEANS, ONE AT A TIME, TO THEREBY CONNECT DIFFERENT ONES OF SAID FEEDBACK PATHS TO SAID AMPLIFIER, WHEREBY AN OUTPUT SIGNAL OF THE FREQUENCY OF THE CRYSTAL ASSOCIATED WITH THE CONNECTED FEEDBACK PATH IS GENERATED.