Improved methods and devices for the oscillographic indication or recording of electric and mechanical phenomena

摘要

513,305. Inductance, capacitance, and resistance measurements ; oscillographs; wireless transmitting apparatus. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN. Dec. 24, 1937, No. 35713. Void. Convention date, Dec. 29, 1936. [Class 37] [Also in Groups XXXVIII and XL] Voltages corresponding to electrical or mechanical phenomena are employed to modulate a high-frequency generator the output of which is supplied to a rectifier and the rectified current being applied to the circuit of an oscillograph. The energy from the generator may be radiated in space to the rectifier receiver, or the rectifier can be connected to the oscillograph by long leads. Stress variations, and pressure diagrams of prime movers can be recorded. Fig. 1 shows a high voltage supply to an X-ray tube 2, a characteristic curve of which is indicated on a cathode-ray oscillograph 16. A resistor 3 in the high-voltage lead is included in the anode circuit of screened oscillator 4 coil 6 of which inductively coupled to rectifier 14 through the coil 12. The rectified output across resistor 15 is proportional to the voltage across resistor 3 and is supplied to one pair of oscillograph plates, the other pair being fed from tappings on potentiometer 17 across the high-voltage supply. The grid bias of the rectifier can be varied to accentuate the trace of particular parts of the modulated current curve. The receiver circuits can be damped, and capacitance coupling between the generator and receiver can be employed, one form of such coupling being shown in Fig. 2, where the insulating supports 11 are hollow and have the coupled coils located on opposite faces. Mechanical phenomena are recorded by causing a variation of capacitance, inductance or resistance in a bridge circuit coupled with the generator, the modulated high-frequency oscillations in this instance being amplified before rectification.