Transistors refer to all single components based on semiconductor materials. Transistors have multiple functions such as detection, rectification, amplification, switching, voltage stabilization, signal modulation, etc. Transistors can be used for various digital and analog functions. Transistors are one of the most critical components of modern appliances, produced on a large scale at extremely low unit costs. Due to its fast response speed and high accuracy, transistors can be used for various digital and analog functions, including amplification, switching, voltage regulation, signal modulation, and oscillators. Therefore, it is necessary to measure transistors. The purpose of a transistor tester is to ensure that the quality and performance of electronic components meet specifications during the manufacturing and production process. This blog will introduce what is a transistor tester and how it works.
Definition and Function of Transistor Tester
Transistor measuring instrument is an electronic instrument based on general electronic measuring instruments and measuring semiconductor devices. It is an electronic detection device mainly used to test various types of transistor characteristic parameters, such as current amplification factor, inter electrode capacitance, leakage current, and other indicators. In addition, the input and output characteristics of the common emitter and common base circuits of transistor (NPN and PNP) can also be tested; Test various reverse saturation currents and breakdown voltages, and also measure various parameters of devices such as field-effect transistors, voltage regulators, diodes, single junction transistors, thyristors, etc.
It has stable performance, can automatically read accurate data, is easy to use, and is suitable for essential small instruments for electronic enthusiasts, electronic developers, designers, and electronic repairers. It can measure various diodes, transistors, thyristors, MOSFETs; and can determine device type, pin polarity, output HFE, valve voltage, junction capacitance of field-effect transistor, and can measure capacitance and resistance under additional conditions. Specially, it is suitable for transistor pairing and identification of mixed surface mount components. A transistor tester can help improve the manufacturing quality of electronic components and minimize losses caused by faulty components.
The Working Principle of Transistor Tester
The working principle of transistor tester is mainly based on circuit testing and measurement. It contains modules such as signal source, measurement, and display inside. When the tested transistor is connected to the test circuit, the signal generated by the signal source will be input into the transistor, and the parameters of the transistor will be measured through the measurement module. These parameters include current amplification factor, cutoff frequency, output impedance, leakage current, saturation current, etc. The measurement module converts the measurement results into digital signals and directly outputs the measurement results through the display module.
The working process of a transistor tester can be divided into the following steps:
- Preparation stage: Insert the transistor to be tested into the tester in the correct direction and secure it tightly. Select the corresponding testing parameters and set them according to the testing requirements.
- Signal input stage: At the beginning of the test, the signal source will generate a signal of a certain frequency and amplitude, and input it into the transistor under test. This signal can be a DC signal, an AC signal, or a pulse signal, depending on the testing requirements.
- Parameter measurement stage: After the signal is input to the transistor, the measurement module will measure various parameters of the transistor.
- Result output stage: After the measurement is completed, the measurement module converts the measurement results into digital signals and outputs them directly through the display module. Users can view test results on the tester and save test records according to their needs.
Precautions for Using Transistor Tester
To ensure the reasonable use of the instrument, without damaging the tested transistor or the internal circuit of the instrument, the following precautions should be taken before using the instrument:
- There should be a general understanding and estimation of the main DC parameters of the tested tube, especially the maximum allowable dissipated power PCM, maximum allowable current ICM, and breakdown voltages BVEBO and BVCBO of the tested tube's collector.
- Choose the polarity of scanning and step signals to adapt to the needs of different tube types and testing projects.
- Select the appropriate scanning voltage range based on the measured parameters or the collector voltage allowed by the tested tube. In general, the peak voltage should be adjusted to zero first, and when changing the scanning voltage range, the peak voltage should also be adjusted to zero first. Select a certain power consumption resistor. When testing the reverse characteristics, choose a larger power consumption resistor and place the X and Y deflection switches in the appropriate positions. During testing, the scanning voltage should be gradually adjusted from zero to the desired value.
- Make necessary estimates for the tested tube to select the appropriate step current or step voltage. Generally, it is advisable to first reduce the step current or step voltage, and then gradually increase it as needed. During testing, the maximum allowable power consumption of the collector of the tested tube should not be exceeded.
- When conducting ICM testing, it is generally advisable to use a single cluster to avoid damaging the tested tube.
- In the testing of IC or ICM, the selection should be based on the actual collector voltage and should not exceed the maximum current specified by this instrument.
- When conducting high-voltage testing, special attention should be paid to safety, and the voltage should be gradually adjusted from zero to the required value. After observation, the peak voltage should be promptly adjusted to zero.
The transistor tester is one of the essential tools for electronic component production and testing. By detecting the characteristic parameters of electronic components, it helps improve production efficiency in the industrial field and ensure product quality standardization. In the process of using a transistor tester, it is necessary to strictly follow the operating requirements in order to ensure the accuracy of the test results and prolong the service life of the equipment as much as possible. To learn more detailed information about transistor testers or other test and measurement equipment, you can browse sisco.com.
