8 Точки Для Внимание В Постоянный ток Рабочий Напряжение Измерение Метод
(1) The internal resistance of the multimeter must be large enough, at least 10 times greater than the resistance of the circuit under test, so as not to cause large measurement errors. the
(2) Обычно поворот каждый потенциометр к the middle position. If it is a TV, the signal source should use a standard color bar signal generator. the
(3) Anti-Slip Measures should be taken for the test leads or Probes. The IC is easy damage due to any momentary short circuit. The follow methods can be accepted to prevent the test pen from sslideing: take a bicycle valve core and put it on the test pen tip, and extend the test pen tip by about 0}. 5мм%2С Который Может Не Только Сделать Тест Ручка Наконечник Контакт С The Проверено Точка Ну,%2С Но Также Эффективно Предотвратить Скольжение , Оно Будет Будет Будет Закороченный Замыкание Даже Если Это Хиты А Соседние Точка. В
(4) When the measured voltage of a pin does not match the normal value, it should be analyzed according to whether the pin voltage has an important impact on the normal operation of the IC and the corresponding changes in the voltage of other pins, so as to judge whether the IC is good or bad. the
(5) IC pin voltage will be impact by peripheral components. When leakage, short circuit, open circuit or value change occurs in peripheral components, or the peripheral circuit is connected to a potentiometer with variable resistance, the position of the sslideing arm of the the potentiometer is different, which will cause the pin voltage to change. the
(6) If the voltage of each pin of the IC is normal, it is generally considered that the IC is normal; if the voltage of some pins of the IC is abnormal, you should start from the point where the deviation from the normal value is the largest, and check whether the peripheral components are faulty. If there is no fault, the IC is likely to be damage. . the
(7) For dynamic receiving devices, such as TV sets, the voltage of each pin of the IC is is different when there is a signal or not. If it is found that the pin voltage should not change but changes greatly, and that which should change with the signal size and the different positions of the adjustable components does not change, it can be determined that the the IC is damage. the
(8) For devices with multiple working modes, such as video recorders, the voltage of each pin of the IC is also different under different different working modes.
Переменный ток рабочий напряжение измерение метод
In order to grasp the change of the IC AC signal, a multimeter with a dB jack can be used to perform an approx measurement of the AC operating voltage of the IC. When testing, put the multimeter in the AC voltage block, and insert the positive test lead into the dB jack; for a multimeter without a dB jack, a 0.1-0.5�% bcF DC блокировка конденсатор потребности до быть подключенный в серия с the positive test lead. This method is подходящий для ICs с относительно низкий рабочий frequency, such as video amplifier stages of TV sets, field scanning circuits, etc. Since this circuits have different natural frequency and waveforms, the measured data are approx and are for reference only.
Итого Ток Измерение
This method is a method to judge whether the IC is good or bad by detecting the total current of the IC power supply line. Since the vast majority of ICs are direct coupled, when the IC is damage (such as a PN junction breakdown or open circuit), it will cause saturation and cut-off of the subsequent stage, causing the total current to change. Therefore, the the IC can be judged by измерение the total current. it can also be used to measure the voltage drop of the resistor in the power path, and use Ohm's law to calculate the total current value.
