| 摘要 |
PURPOSE:To fix frequency characteristics independently of magnification and remove any change with priority given to magnification by compensating the loop gain fequency characteristics of an electron beam deflection circuit in relation to detection resistor and almost completely prevent the frequency characteristics from being changed. CONSTITUTION:A frequency characteristic variable circuit (F characteristic circuit) 11 whose frequency characteristics can be switched interlocking with a select switch 4 is inserted and connected between an error amplifier 1 and a power amplifier 2. In this case, the frequency characteristics of the F characteristic circuit 11 have three frequency characteristics F1 to F3 as shown in the figure and these frequency characteristics are alternatively selected interlocking with the select switch 4. As a result of such a selection, the open loop gain Gopen in the circuit always shows the same characteristics independently of the switching of detection resistor R0 as shown in the figure. As a result, even if magnification is switched, there does not occur any change in the loop gain frequency characteristics of a deflection circuit system and there does not appear any phase change in the deflection coil current. Thus, a change with priority given to magnification can be removed. |
