| 摘要 |
<p>1410380 Amplifier circuits ELEKTROAKUSZTIKAI GYAR 14 Dec 1972 [15 Feb 1972] 57858/72 Heading H3W A tone control circuit comprises: an amplifier having inverting and non-inverting inputs; resistors R<1>1, R2 connecting the inputs respectively to earth; a feedback resistor R<1>2 connected between the output and the inverting input; and a potential divider P1 or P2 connected between the two inputs with its tapping point connected to earth via a resistance/reactance circuit. For low frequency control, Fig. 3, the resistance/reactance circuit includes inductive reactance L and a resistance capacitance circuit C1, R1 connected between a signal input terminal and the non-inverting amplifier input. For high frequency control, Fig. 8, the reactance is a capacitor C, and the resistance-capacitance circuit comprises a series resistor R1 and a shunt capacitor C2. For more complex control, various combinations of L, C, R may be used in the resistance-reactance circuit, and the resistance capacitance circuit may comprise series and shunt capacitance Fig. 16 (not shown), a number of potential dividers, each with its own resistance-reactance circuit may be connected in parallel, Figs. 12, 14 (not shown), and a number of such tone control circuits may be connected in parallel Figs. 18, 19 (not shown). The potential divider may comprise two fixed resistors Fig. 11 (not shown), and the input signal may be applied via a transformer.</p> |
