Patent ID: 6529388
Filing Date: 2003-03-04
Classification: G03G,H02M

Abstract:
A high voltage generating apparatus for use in a toner system printing device comprising:a transformer wound by a primary coil, a secondary coil and an auxiliary coil; a transistor for oscillation with a collector connected to said primary coil and a base connected to the one terminal of said auxiliary coil, said transistor performing self-excited oscillation within a non-saturated range; a rectifying/smoothing circuit for rectifying/smoothing an output from said secondary coil to create an secondary output; a detecting signal creating circuit for rectifying/smoothing an output from a voltage detecting coil to create a voltage detecting signal indicative of a voltage of the secondary output; and a voltage control circuit for supplying a DC voltage control signal created on the basis of the voltage detecting signal to the other terminal of said auxiliary coil, wherein said voltage control circuit controls the oscillating amplitude of said transistor using the DC voltage control signal to stabilize the voltage of the secondary output, the secondary output is led to a high voltage applying portion of a toner system printing section, and said detecting signal creating circuit rectifies the output from said voltage detecting coil at the same timing as said rectifying/smoothing circuit rectifies the output from said secondary coil.