| 摘要 |
1300611 Transistor oscillator circuits; modulators UTI 1 Jan 1970 100/70 Headings H3R and H3T A solid state RF power supply for a quadrupole spectrometer comprises an oscillator operating with a series tuned tank circuit coupled to the quadrupole rods, an amplifier being provided in the feedback path from the tank circuit. Coupling between the tank circuit and the quadrupole rods may be by way of a parallel tuned circuit, Fig. 1, or may be direct Fig. 2 not shown. In Fig. 1 the oscillator has a push-pull stage 11, 12, operating into first and second tuned circuits comprised of transformer primary windings 36, 40, and capacitors 35, 38. Quadrupole rods 13 are coupled by parallel tuned circuits comprised of transformer secondary windings 50, 51 and capacitors 52 and 53. Capacitors 41, 43 take feedback from the tank circuits to emitter followers 14, 15 cross-coupled to stage 11, 12. Hot filament bulb 24 in the base circuit has a resistance which increases with feedback and biases the transistors to class C operation. The RF envelope developed in the tank circuit is modulated by transistor 58 in accordance with the difference between a controlling program signal and a signal from RF detector 18, such difference being taken and presented by an integrated circuit operational amplifier 17. Capacitors 63, 64 coupled to the transformer secondary windings 50, 51 provide D.C. voltage output to the quadruple rods in proportion to the RF output. If the transformer windings 36, 40, in the tank circuit are connected directly to the quadruple rods, Fig. 2, not shown, the D.C. rod voltages are obtained from these windings by way of RF chokes and feedback from the tank circuit is obtained from feedback windings on the transformer. |
