| 摘要 |
PURPOSE: A degaussing circuit is provided to prevent a cathode ray tube from being susceptible to the effect of earth magnetic fields by degaussing without using PTC-thermistor for initial time that an equipment is powered on. CONSTITUTION: The degaussing circuit includes a time delaying portion(10), a trigger signal generating portion(12), a switching unit(SCR) and a degaussing portion(14). The time delaying portion delays a predetermined set time during a voltage is charged at an initial time when a power switch is turned on. The trigger signal generating portion generates a trigger signal when the voltage charged in the time delay portion goes over a set level. The switching element turns on when the trigger signal is generated from the trigger signal generating portion. The degaussing portion is charged at the initial time when the power switch is turned on, and discharges the charged voltage when the switching element is turned on and thereby a degaussing current flows to a degaussing coil. A first switch(SW11) is connected between the time delay portion and a power supply(Vcc11). A second switch(SW13) is connected between the switching element and a power supply(Vcc13).
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