One, travel drive is in charge of and the emissive knot voltage of travel efferent and collector volts d.c. measure a way

Through measuring voltage of travel efferent collector, can judge an output level to whether be put in dc short circuit; Voltage makes clear nonexistent dc short circuit normally, but cannot output class for certain accordingly breakdown of nonexistent open a way.

Can judge breakdown through measuring an efferent to launch knot voltage be expert at output level or the circuit before its. Voltage of this emissive knot is what losing 0.25V less than to slanting normally or slant instead, this and the incentive way that drive transformer all right and pulse lose by force about. If launch knot voltage normal, explain the circuit before travel efferent is basic and normal; If launch a knot not to have voltage, the specification drives class to did not offer incentive pulse or travel canal to launch knot puncture all right. When travel drive provides regular job, emissive knot bias voltage is 0.4V. Bias voltage shows an oscillating circuit to output normal line frequency pulse normally; Bias voltage size or without travel of bias voltage specification oscillating circuit works unusual or travel drive provides emissive knot breakdown; Bias voltage exceeds 0.75V to make drive is in charge of saturation to guide, can make force of its collector voltage 0, this also is an oscillating circuit the job is unusual.



2, drive pneumatics all right implement law of primary short circuit

If voltage of travel efferent collector is apparent under normal value, can drive transformer all right through short circuit primary winding will judge short circuit of dc of presence of travel output level or communication short circuit. The travel after short circuit is in charge of base not to have input pulse, travel canal does not work at pulse condition. Accordingly, if tubal collector voltage goes to return to normal after short circuit, explain presence of travel output level communicates short circuit, common breakdown is travel deflexion coil interior of transformer of output of local short circuit, travel circles a short circuit or its load short circuit. If tubal collector voltage goes after short circuit still on the low side, explain to output short circuit of stage presence dc all right, common breakdown is in charge of diode of the leakage of electricity between Ce pole, damp to go undesirable or retrace capacitance leakage of electricity.

Ask an attention, this kind of method is not applicable to certain color television. For example, certain color television uses power source of switch of the formula that lock up frequency, go by travel retrace pulse synchro switch power source, be expert at when circuit does not work, the output voltage of switch power source can drop. If lack the experience of this respect, meeting mistake outputs short circuit of stage presence dc to go: Be like again, power source of switch of certain self-excitation formula if movement of 3 foreign 83P and blessing day F91PP TDA of the power source of two machine advocate output voltage, be expert at because load is reduced and the meeting when output level does not work rises to 143V and 130V, may cause not due trouble.
Previous12 Next