CIRCUIT ASSEMBLY FOR GENERATING RF OSCILLATING PLUCKING PULSE

摘要

PROBLEM TO BE SOLVED: To properly use the usable energy within an accumulating element. SOLUTION: The circuit assembly in the resonance circuit (12) of a transponder (10) not having a battery power source generates a maintenance pulse, i.e., a plucking pulse each time the amplitude of RF oscillation drops under a specified threshold value and the instant value gets in the specified relation with the reference voltage (VPREAK) which changes with time as the charge voltage of a capacitor (70). This is provided with a switch (24) which can be switched to be ON during the period of this plucking pulse (PLUCK) and is used to connect the above accumulating element (20) to the resonance circuit (12), and is further provided with closed control loops (34 and 38) which change the inclination of the reference voltage curve between the two plucking pulses (PLUCK), in the direction of keeping the specified relation between the instantaneous value of the above RF oscillation signal and the reference voltage.