Title:
AUTOMATIC SYSTEM FOR ADJUSTMENT AND CONTROL OF FREQUENCY
Document Type and Number:
Japanese Patent JPH04233337
Kind Code:
A
Abstract:
PURPOSE: To improve the reliability by comparing a transmission frequency detected from a power line with an upper limit frequency and a lower limit frequency and reducing or increasing the resistance value of a resistance varying part in accordance with the comparison result to set the transmission frequency. CONSTITUTION: When a low potential signal is applied to an input terminal A of a CPU 9 and a high potential signal is applied to an input terminal B, it is recognized that the transmission frequency of a resonance transmission part 1 is higher than the upper limit frequency. A resistance value set control signal CS is reduced by one step, and then, a switch SW1 of a resistance varying part 10 is reduced by one step and is connected. When a low potential signal is applied to the terminal A of the CPU 9 and a high potential signal is applied to a terminal C, it is recognized that the transmission frequency of the transmission part 1 is lower than the lower limit frequency, and the signal CS is increased by one step, and the switch SW1 of the varying part 10 is increased by one and is connected. Thus, the resistance value of the varying part 10 is reduced or increased by one step to set the transmission frequency of a carrier transmission part 2, and data of the transmission part 1 is accurately converted.
Inventors:
GO YON DEU
Application Number:
JP15045491A
Publication Date:
August 21, 1992
Filing Date:
June 21, 1991
Export Citation:
Assignee:
GOLD STAR CO
International Classes:
H03L7/00; H02J13/00; H03J7/02; H04B3/54; (IPC1-7): H03J7/02; H04B3/54
Attorney, Agent or Firm:
Aoki Akira (4 outside)