Check the digital tube with a multimeter

Knowledge point : How to use a multimeter to detect the pin arrangement of a nixie tube

For a digital multimeter , The red probe is connected to the positive pole of the internal battery of the meter , The black probe is connected to the negative pole of the internal battery of the meter , When the digital multimeter is placed in diode position , The open circuit voltage between the two probes is about 1.5V, When the two probes are correctly added to both ends of the LED , Light emitting diodes can be turned on .

Pictured 3.1.5 Shown , Place the digital multimeter in diode position , The red pen is connected to ① foot , Then use the black lead to contact other pins , Suppose only when you come into contact with ⑨ Foot time , The digital tube a Duan Guangming , When touching other pins, it does not emit light . Thus we can see that , The digital tube under test is of common cathode structure ,⑨ The foot is a common cathode ,① The feet are digital tubes a paragraph . Next, check the pins of each section , Still use the digital multimeter diode block , Fix the black probe to ⑨ foot , Touch with the red pen in turn ②、③、④、⑤、⑥、⑦、⑧、⑨ Pin time , The other segments of the nixie tube light up successively , Accordingly, the internal structure and pin arrangement diagram of the digital tube can be drawn .

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When 4 The bit selector of the bit nixie tube is connected to 38 Decoder , Segment line selection connected 74ls573 when （ Not powered on ）
problem ： Multimeter red and black probes Come into contact with Two bit line selection of digital tube , After that The lamp of the digital tube cannot be turned on when the multimeter is tested .
resolvent ： The red and black probes of the multimeter touch two sections for line selection , Use a multimeter to measure again .