​Maintenance instructions for electronic crane scale

Maintenance instructions for electronic crane scale

 Electronic crane scale principle is relatively simple, various specifications, models of electronic crane scale principle line and structure is also roughly similar. But the electronic scale produced by each manufacturer has its own characteristics in the selection of circuit components and technology.

The circuit structure of electronic crane scale is composed of power supply, weighing sensor, analog signal amplifier, analog-to-digital converter, single chip microcomputer, driver display, keyboard, printout interface and other parts.

 Electronic crane scale basic principle: the force of gravity acting on the object make the strain gauge on the weighing sensor elastomer composed of wheat stone bridge produced around 0 ~ 25 v sensor signal (the size of the signal is proportional to the weight), after the sensing signal analog signal amplifier amplification of 0 ~ 3 v or so, and then through analog conversion circuit to simulate voltage of some code Numbers. Finally, through the single-chip microcomputer control unit price Settings, the amount of calculation, a variety of parameters sent to display, through the display of weight, amount, unit price and other data.

 Maintenance instructions for electronic crane scale

 Maintenance personnel must have a certain basic theoretical knowledge, and have an understanding of the verification procedures. Because the price scale of each manufacturer choose another component is not the same, the line is also different, so the maintenance staff can not be disassembled without understanding the working principle of the scale. Read the scale manual carefully first, study the circuit diagram, the working principle of the scale, the logic relationship between the role of each part of the circuit should have a certain understanding of the scale disassembly method, familiar with the structure of the scale, the connection form of the plug and the assembly relationship, and then the fault analysis and start to repair.

 Electronic crane scale fault inspection method

 It is very important to determine the location of the fault quickly and accurately in the maintenance work. On the basis of being familiar with the operation and structural principle of the pricing scale, the maintenance personnel of the electronic crane scale must be able to use the measuring instrument correctly and master the basic repair method of the pricing scale. The following are some common fault inspection methods:

 1. The intuitive method

 There are many components on the main circuit board of electronic crane scale, and many faults are caused by short circuit, broken circuit, poor contact between connection and insertion, and corner welding of parts and tubes. Therefore, when the scale failure, should first use intuitive feeling: visual, listening, smell, touch and other methods to check the circuit board.

 2. Comparison and substitution

 In the fault inspection, the electronic crane scale with the aid of the instrument and the scale with the fault of comparison, can quickly find out the fault point. In addition, the prepared sensor, circuit board, power supply, keyboard and other components in the work, if it is suspected that the sensor, circuit board, power supply, keyboard and other components are damaged, replace them with the prepared components, and then observe whether the results have changed, if the display is normal, it means there is a problem with the original components. The comparison and substitution method can quickly and accurately judge the fault point.

 3. Voltage measurement method

 Electronic crane scale through the circuit components, chip each tube Angle of the voltage measurement and normal value of comparison, the voltage change is the place where the fault.

 4. Short circuit and open circuit

 Short circuit method is to short a part of the circuit, electronic crane scale and then through the oscilloscope or multimeter test results to determine the fault point. The open circuit method is to disconnect a part of the circuit and use a multimeter to measure resistance, voltage, or current to determine the point of failure.