Setting circuit of binary threshold value

A binary threshold value setting circuit comprising:

• a first detecting section to detect the positive polarity side of an input signal;
• a second detecting section to detect the negative polarity side of said signal;
• a first capacitor connected to said first detecting section to perform an envelope detection to the signal detected by the first detecting section;
• a second capacitor connected to said second detecting section to perform an envelope detection to the signal detected by the second detecting section;
• a threshold value setting section connected to said first and second capacitors to generate a signal at a level between the level of the signal which has been envelope detected by the first capacitor and the level of the signal which has been envelope detected by the second capacitor;
• a third capacitor which is connected between an output side of the first detecting section and an output side of the second detecting section and has a capacitance larger than capacitances of the first and second capacitors;
• a resistor connected between an output side of the first capacitor and an output side of the second capacitor;
• and
• a switching device connected between the output side of the first capacitor and the output side of the second capacitor, said switching device being connected in paralleled with said first and second capacitors.

A binary threshold value setting circuit comprising:

• a first detecting section to detect the positive polarity side of an input signal;
• a second detecting section to detect the negative polarity side of said signal;
• a first envelope detecting section connected to said first detecting section to perforth an envelope detection to the signal detected by the first detecting section;
• a second envelope detecting section connected to said second detecting section to perform an envelope detection to the signal detected by the second detecting section;
• a threshold value setting section connected to said first and second envelope detecting sections to generate a signal at a level between the level of the signal which has been envelope detected by the first envelope detecting section and the level of the signal which has been envelope detected by the second envelope detecting section;
• a capacitor connected between an output side of the first detecting section and an output side of the second detecting section;
• a first discharge section, connected to an output side of the first envelope detecting section, for allowing the charges charged in the first envelope detecting section to be discharged;
• and
• a second discharge section, connected to an output side of the second envelope detecting section, for allowing the charges charged in the second envelope detecting section to be discharged.

A binary threshold value setting circuit comprising:

• a first detecting section to detect the positive polarity side of an input signal;
• a second detecting section to detect the negative polarity side of said signal;
• a first capacitor connected to said first detecting section to perform an envelope detection to the signal detected by the first detecting section;
• a second capacitor connected to said second detecting section to perform an envelope detection to the signal detected by the second detecting section;
• a threshold value setting section connected to said first and second capacitors to generate a signal at a level between the level of the signal which has been envelope detected by the first capacitor and the level of the signal which has been envelope detected by the second capacitor;
• a third capacitor which is connected between an output side of the first detecting section and an output side of the second detecting section and has a capacitance larger than capacitances of the first and second capacitors;
• a first resistor connected to an output side of the first capacitor at one end thereof, and grounded at the other end through a first switching device;
• and
• a second resistor connected to an output side of the second capacitor at one end thereof, and grounded at the other end through a second switching device.