METHOD AND DEVICE FOR READJUSTING RESONANT FREQUENCY OF DUMMY OSCILLATORY CIRCUIT USING S-TYPE ELEMENT Russian patent published in 1997 - IPC

FIELD: electronic engineering. SUBSTANCE: method involves variation of S-type element turn-on voltage by means of control signal: , where Uinon

is initial turn-on voltage of S-type element at U_c= Uinc; is S-type element turn-on voltage at ; variation of supply voltage obeying law E_s= E_no±ΔU_on, where E_so is initial value of supply voltage; determination of negative differential resistance at , where Uinoff, Iinon, Iinoff are turn-on voltage, turn-on and turn- off currents of S-type element, respectively, at , this being followed by determination of negative differential resistance increment obtained at initial control voltage Uinc(IR-Iⁱⁿ) and its present value : . Then current-setting resistor value is varied by ΔR_o according to dependence , where Rino is current-setting resistor value at initial control voltage Uinc. Resonant frequency f_r is measured by panoramic meter at different control voltages. Device implementing this method has power supply, loading resistor, milliammeter, voltmeter, capacitor, S-type element built up of n-p-n and p-n-p transistors and four resistors. It also has newly introduced four n-p-n transistors, thirteen resistors, second capacitor, and panoramic meter. Collector of second n-p-n transistor whose emitter is connected to common bus is connected via resistor to first resistive divider inserted between output terminal and base of first n-p-n transistor. Collector of third n-p-n transistor is connected to positive pole of power supply and its emitter, to loading resistor; resistor is inserted between its collector and base. The latter is connected via resistor to collector of fourth n-p-n transistor. Base of second n-p-n transistor is connected via resistor to collector of fifth n-p-n transistor. Circuit of series-connected second capacitor and panoramic meter is inserted between output terminal and common bus. EFFECT: extended resonant frequency variation range at same Q-factor. 2 cl, 5 dwg