Multi-purpose regulator integrated circuit tester, Regulator Tester
Keywords: regulator circuit test circuit
Author: Chen Jian Su
The schematic diagram of this test instrument is shown below, mainly for testing the following five types of components:
1, current source element; 2, precision reference voltage source; 3, adjustable positive negative voltage output integrated regulator; 4, fixed positive voltage output integrated regulator; 5, fixed negative voltage output integrated regulator Wait.
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The equivalent circuit diagram of various common components tests for various types of varieties is shown below, in which: The following picture is the test schematic of the three-terminal adjustable current source LM134 / 234/334. To simplify the test line, it is easy to transfer the current test of the adjustable current source to a similar LM317 adjustable integrated regulator reference voltage VREF. The set current in Fig. 1 is about 8.3 mA, and can be used as the minimum load current at the time of test of the LM 317, 337. At this time, the pressure drop on the R2 (150Ω) resistance is about 1.25 V. If the voltage measured by the digital multimeter is around 1.25V, the reading is substantially unchanged when the output voltage of the voltage regulator is changed, and the component is good.
B, B, C, D, E are the test schematic of various precision reference voltage sources. Among them: The reference voltage of the LM335 is about 2.98V; the reference voltage of the LM336 is between 2.25V and 2.5V; the reference voltage of the TL431 is about 2.25. The reference voltage of TLV431 is 1.25. V or so.
The following picture f is the test schematic of the LM317 adjustable voltage output integrated regulator. Its reference voltage VREF is around 1.25V. The minimum load current at the time of test is around 8.3 mA. Requirements for minimum load currents in normal operations.
The following picture g is a test schematic of the integrated regulator for the LM337 adjustable negative voltage output. Its reference voltage VREF is around -1.25V, and the minimum load current is also around 8.3 mA.
The following figure h is the test schematic of the LM337L, 2, and 3 pins are just in contrast to the Pin of the LM337.
The following Figure 1 is a test schematic of the integrated regulator for the LM78XX fixed positive voltage output. Where xx is the voltage regulator voltage output from the device, there are 5V, 6V, 8V, 9V, 12V, 15V, 18V, 24V and other voltages.
The following picture j is the test schematic of the LM78LXX fixed positive voltage output regulator. 3, 1 pin is just in contrast to the pin at the LM78XX.
The following picture k is the test schematic of the integrated regulator for the LM79XX fixed negative voltage output. Also have a negative output voltage of -5V to -24V.
The tester's line is simple, similar to the general universal number of lines, but only 3 resistors and 2 capacitors are used. In the drawings, K1-1 ~ K1-4 uses double-layer double-knife five-bit wave section switch for selecting the type of test device. Among them: 1 gear is the adjustable power source to test RIV, such as LM334, etc.; 2 gear is a precision reference voltage source test gear, such as a fixed LM335, LM336, LM385, and adjustable TL431, etc .; 3 is movable as an adjustable positive negative voltage Output integrated regulator test gear, such as LM317, LM350, LM337, etc.; 4 gear to fixed positive voltage output integrated regulator test file, such as LM78XX series, etc.; 5 gear to fixed negative voltage output integrated regulator test gear, such as LM79XX series, etc. BG is an external O ~ 30V adjustable power supply. K2-1 ~ K2-2 is a double-knife double throw switch, and the power supply polarity when the positive and negative voltage output is used. AN is button.
Press the button to press the button to read the voltage parameters of the various components. The test results show the external digital multimeter. When the reading is a negative value, it indicates that the tested components are an integrated regulator that is negative voltage output.
The pin socket uses an outlet of an 8-pin integrated circuit. The above four jacks are mainly used to measure the elements of the positive voltage output, such as 1, 2, 4 and 3-stop LM317 (individual negative voltage output elements, such as LM337L, etc.). The tube holder jack number is labeled P, such as P-2-3-4, indicating that the 1-2-3 foot of the component is inserted into the 2-3-4 jack of the positive voltage output P-riser. A row of 4 jacks under the tube is used to measure the adjustable and fixed integrated regulator of negative voltage output, such as LM337, LM79XX, and the like. The tube holder is labeled N, such as N-1-2-3 represents the 1-2-3 pin of the component in the negative voltage output N-tube holder 1-2-3 jack. C1, C2 capacitance plays a stable effect to prevent oscillation.
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Measurement method 1, connect the external voltage regulator power supply and the digital multimeter to the tester; 2. Dial the type selection switch K1-1 ~ K1-4 to the required gear according to the type of test element, see the following table; 3 The pin number of the test element is contemplated as a front side, and its pin is selected from left to right. Section 1, 2, 3. Insert the component tube inserted within the jack corresponding to the socket in the attached table; 4, the polarity switch k2 output from the voltage output is dial to the correct or reverse position as needed, and the power supply in the above figure is a correct state; 5, Press the button to read the results of the measurement from the digital multimeter. Good components have their readings between the maximum and minimum values in the component manual, and change the output voltage of the regulated power supply (which must be adjusted between the minimum and maximum input voltage of this type of component). Change.
Table 1 is shown in Table 1 for detailed testing of various components. If there is an abnormal condition, the AN button should be quickly released. Such as: The reading is deviated from very large, and the voltage limit of the power is limited. This is generally bad in the inspection operation and the reading results are generally bad.
Due to many manufacturers of integrated regulators and various reference voltage current source devices, there are many packages, and there are many packages; additional new components are constantly developing, such as integrated regulators such as low pressure differences, therefore Only use of common models, other types and models of components (including integrated sensors, etc.) can be used according to principles and manual. Testing the TO-3 packaged components, self-made replacement maker connectors.
The tester line is simple, low cost, easy to make, and more test components, and numerous species, the test data can provide a basis for electronic circuitry.
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