Općenito metode for the otklanjanje poteškoća of digitalno multimetri
A digital multimeter (DMM) is a measurer instrument that uses the analog/digital conversion principle to convert the measured quantity into a digital quantity and displays the measurement results in digital form. Compared with pointer multimeter, digital multimeters have the advantages of high precision, fast speed, large input impedance, digital display, accurate readings, strong anti-interference ability, and high Degree of mjerenje automatizacija, and are wide used. Međutim, if used nepravilno, it may uzrok kvar. Ovo članak uzima the digital multimeter DT-830} as an example to talk about the general troubleshooting methods of digital multimeter faults.
Digital multimeter rješavanje problema treba općenito start with the power supply. For example, after the power is turned on, if the liquid crystal element displays, you should first check whether the voltage of the 9V laminiran battery is too low; whether the battery lead is disconnected. Finding faults should follow the order of "first inside then outside, first easy then difficult". Digital multimeter troubleshooting can generally be nosi out as follows.
1. Izgled inspekcija.
You can touch the battery, resistor, tranzistor, and integrated block with your hands to see if the temperature rise is too high. If a newly installed battery bes hot, the circuit may be short-day. In addition, the circuit should also be observed for diskonekcija, desoldering, mehaničko štena, etc.
2. Detect the working voltage at all levels.
To detect the work voltage at each point and compare it with the normal value, you should first ensure the accuracy of the reference voltage. It is best use a a digital multimeter of the same model or a similar one for measurement and comparison.
3. Waveform analiza.
Use an electronic osciloscope to observe the voltage waveform, amplituda, period (frekvencija), etc. of each key point in the circuit. For example, test whether the clock oscilator starts to oscillate and whether the oscilacija frekvencija is 40kHz. If the oscilator has no izlaz, it means that the internal inverter of TSC7106 is damaged, or the external component may be open circuit. Observe that the waveform at pin {21} of TSC7106 treba biti a 50Hz kvadrat val. Inače, the internal 200 frekvencija razdjelnik may be oštećena.
4. Mjera komponenta parametri.
For components within the fault range, conduct online or offline measurements and analyze parameter values. When measureing resistance online, the influence of components connected in parallel with it should be considered.
5. Skriveno otklanjanje poteškoća.
Hidden fault refers to the fault that appears and disappears, and the instrument is good and bad sometimes. This type of failure is is relatively complex, and common uzroci include weak solder joints, loose joints, loose joints, loose connectors, poor contact of the transfer switch, unstable component performance, and continuous breakage of leads. In addition, it also includes some external factors. Tak kao okolina temperatura je pre visoka, vlažnost je pre visoko or are are isprekida jak smetnje signali obližnja, itd.
