GM328A Transistor Diode Tester Tool ESR Voltage Frequency Meter

Note:

Before testing the capacitor, discharge the capacitor before inserting it into the test holder for measurement, otherwise there is a risk of damaging the tester's microcontroller.

1,Calibration

The tester calibration is used to eliminate errors in its own components, making the final test results more accurate. Calibration is divided into quick calibration and full function calibration.
The operation method for quick calibration: short the three test points TP1, TP2 and TP3 with wires and then press the test button while watching the screen. The screen colour will change to white text on a black background. After the prompt message "Selftest mode...? ", press the test button to enter the fast calibration process; if, after the message "Selftest mode...? If no button is pressed within 2 seconds after the message "Selftest mode...", the normal test process is carried out and the resistance values of the three test points TP1, TP2 and TP3 are displayed at the end. After entering the quick calibration process, some data will appear on the screen, ignore it. Wait until a flashing string appears on the screen
After "isolate Probes!", remove the shorted TP1, TP2 and TP3 leads. The quick calibration is complete until the string "Test End" appears on the screen. When calibrating for the first time, use the full function calibration method.
The full function calibration is accessed from the function menu and requires an additional 220nf capacitor. Full function calibration performs a more comprehensive calibration process and can take longer. Once in the function menu, turn the test button to the menu item "Selftest", then press the test button to enter the full function calibration process, which starts with the flashing string "short Probes! When the flashing string "isolate Probes!" appears on the screen, remove the wires from the three test points and continue to wait for the calibration process to proceed, when the string "1-||- 3 > 100nf", install the prepared 220nf capacitors on test points TP1 and TP3. Wait until the screen says "Test End" and the fully functional calibration process is complete.

2. Function menu

2.1 Switch off
2.2 Transistor
2.3 Frequency
Measures the frequency. Press and hold the test button to exit the frequency measurement function. The frequency measurement range is from 1 Hz to more than 1 MHz, when the measured frequency is below 25 KHz, the period is displayed
2.4 f-Generator
Square wave generator with multiple square wave frequencies selectable, turn the test button left or right to switch between different square wave frequencies, long press the test button to exit the square wave generator.
2.5 10-bit PWM
Pulse generator, left or right turn the test button to adjust the duty cycle of the pulse from 1% - 99%. Press and hold the test button to exit the pulse generator.
2.6 C+ESR@TP1:3
Capacitance in-line measurement function, two wires can be led from TP1 and TP3 to measure the capacitance value and ESR of a 2uF-50mF capacitor in-line, note that the capacitor under test needs to be completely discharged before the test, if the measurement is in-line, the circuit where the capacitor is located needs to be completely disconnected before the test can be carried out.
2.7
Resistance continuous measurement method, constantly test the resistance value and inductance value installed on TP1 and TP3. The inductance is measured only when the resistance under test is less than 2100 ohms, and the inductance is measured from 0.01mH to 20H . Press and hold the test button to exit.
2.8 1-||-3
The capacitance continuous measurement method continuously tests the capacitance values mounted on TP1 and TP3. For small capacitance capacitors, the capacitance values can only be measured in this test method. The equivalent series resistance (ESR) value is measured for capacitors greater than 90nF with a resolution of 0.01Ω. capacitors above 5000pF show their voltage drop rate after charging.
2.9 DS18B20 Russian version without this function
The DS18B20 is a temperature sensor that uses a single bus communication method to transfer data and has the same package as the triode (TO-92), the diagram below shows the pinout of the DS18B20.

After entering the DS18B20 test function, the second line of the display shows the connection between the test holder and the DS18B20, "1=GND 2=DQ 3=VDD", indicating that TP1 is connected to the GND of the DS18B20, TP2 is connected to the DQ of the DS18B20 and TP3 is connected to the VDD of the DS18B20. The tester does not automatically recognise the DS18B20, so you must follow the instructions in the second line to install the DS18B20.
The tester can read the 12-digit temperature result measured by the DS18B20 and display it in the third line as the corresponding Celsius temperature value with a resolution of 0.0625°C.
Scratchpad: The tester reads the contents of the 8 internal memory cells of the DS18B20 plus the last byte of the CRC check value. 9 bytes in total.
Scratchpad BYTE
TEMPERATURE LSB 0
TEMPERATURE MSB 1
TH/USER BYTE 1 2
TL/USER BYTE 2 3
CONFIG 4
RESERVED 5
RESERVED 6
RESERVED 7

CRC 8

For example, if the value read at one time is Scratchpad: EC014B467FFF0C102A then the relationship is as follows
Scratchpad Value BYTE
TEMPERATURE LSB EC 0
TEMPERATURE MSB 01 1
TH/USER BYTE 1 4B 2
TL/USER BYTE 2 46 3
CONFIG 7F 4
RESERVED FF 5
RESERVED 0C 6
RESERVED 10 7

CRC 2A 8

64-bit ROM: The globally unique device ID of each DS18B20 read by the tester, which is 64 bits long. It is divided into 3 parts.

For example, the 64-bit ROM read by a DS18B20 is
64-bit ROM: 28FF4D58361604A1
then there is
8-BIT FAMILY CODE 28
48-BIT SERIAL NUMBER 041636584DFF
8-BIT CRC CODE A1

Note: All parts are in hexadecimal, except for the temperature value (TEMP), which is in decimal.
The temperature measurement range of the DS18B20 is from -55°C - 125°C. Press and hold the test button to exit this function.
2.10 C(uF)-correction
This function is used to correct the measured value of the high-capacity capacitance, which is set to 0% by default. This means that there is no correction and is set from -0.2% - 8%. A positive value will reduce the measured value of the capacitor and a negative value will increase the measured value of the capacitor.
After setting, press and hold the test button to exit.
2.11 IR_Decoder Russian version without this function
This function requires the use of an 1838 integrated IR receiver (pulse type), after entering this function, observe the second line of the prompt on the display which shows the string ""1=DOUT 2=GND 3=VCC", the meaning of the string indicates the 3 test points on the tester and the IR receiver. The string indicates the connection between the 3 test points on the tester and the IR receiver head, which must be connected in strict accordance with the instructions. Only one IR receiver can be left empty or correctly installed in the test stand, no other components can be placed in it, and the test points must not be shorted with wires. This is to avoid unpredictable faults. The diagram below shows the mounting orientation of the example IR receiver head.
TP1 is connected to the DOUT pin of the IR receiver head, TP2 to GND and TP3 to VCC.
The IR remote control decoding function supports two IR remote control coding formats.
Format I
Format 2

The above two formats are roughly the same, the difference lies in the length of the boot code. Format 1 is 9MS and format 2 is 4.5MS.
The IR remote control decoding function uses uPD6121 for format one and TC9012 for format two respectively.

Operating Instructions
The IR remote control decoding function can only be accessed from the function menu. Before entering the IR remote control decoding function, there must not be any components on the test stand or on the square wave output terminals. Enter the IR remote control decoding function and wait until the display shows the "standing by..." After the string "standing by..." appears on the display, put the integrated IR receiver head into the test base and lock it in place. The remote control can then be pointed at the IR receiver head and fired. If the code used for the remote control is recognised. The third line will show a string of characters ">>>>>>>>>>>" indicating a successful decode and the fourth line will show the code format used for the remote control. The fifth line shows the first byte of the user code (user code1) and the sixth line shows the second byte of the user code (user code2). The seventh line shows the data code (data) and the data inverse code (~data).
(All values of the IR decoder function are in hexadecimal format.
The IR decoding function only supports single key mode, not continuous mode. When testing this function, I found that several TV remote controls used for testing were TC9012, the small Mp3 remote control was uPD6121, and the air conditioner remote control was not recognized :-(.) Due to the limitations, no further testing could be done.
To exit from this function, remove the receiver head from the test holder and then press and hold the rotary encoder switch to exit.
2.11 IR_Encoder Russian version without this function
The IR remote control encoder function requires an infrared LED. The tester can control this infrared LED and thus implement an infrared remote control function. As the tester can only provide a maximum drive current of around 6mA, the control distance cannot be compared to that of a normal infrared remote control. With the infrared receiver head aligned to transmit, it is probably within 2m.
The IR remote control encoding supports two formats, the same as the IR remote control decoding format described earlier. The uPD6121 is also used to indicate format one and the TC9012 to indicate format two.
Operating instructions
The IR remote control coding function can only be accessed from the function menu. Before entering the IR remote control coding function, there must not be any components on the test stand or on the square wave output terminals. After entering the infrared remote control coding function, connect an infrared LED to the square wave output terminal, with the negative terminal of the infrared LED connected to earth and the positive terminal connected to the output. The positive and negative terminals of the infrared LED can be extended using wires to facilitate operation. The long leg of the infrared LED is positive and the short leg is negative.
In the leftmost column of the display is a ">" symbol indicating which parameter is currently being set. A short press on the test button toggles the ">" between the various setting items. The second line, "protocol", sets the encoding format to be used. Rotating the test button left and right switches between "uPD6121" and "TC9012".
The third and fourth lines "user code1" and "user code2" set the first and second bytes of the user code, which can be decreased in steps of 1 by rotating the test button left and increased in steps of 1 by rotating the test button right.
The fifth line sets the data code, which can be decreased by 1 for the left-hand test button and increased by 1 for the right-hand test button. The data inverse code is calculated automatically from the data code and cannot be set manually.
When setting the value of the user code and data code, in addition to changing the value in units of 1 by rotating the test button left and right, the value can also be increased in units of 0x10 by pressing and holding the test button for a long time, but not too long, if too long, the function is withdrawn. This is not easy to grasp at first. The sixth line is the emit control "emit:". By moving the ">" symbol to this line, the test button can be rotated left and right to emit infrared light according to the data set above. When you turn the test switch, you will see a quick flash of the "->" symbol. This indicates that the data has been emitted once.