How to test the resistance of an electric soldering iron
Electric soldering iron is an essential tool for electronic production and electrical maintenance, mainly used for welding components and wires. It can be divided into internal heating electric soldering iron and external heating electric soldering iron according to mechanical structure. It can be divided into non tin absorbing electric soldering iron and tin absorbing electric soldering iron according to function, and can be divided into high-power electric soldering iron and low-power electric soldering iron according to different purposes.
The electric soldering iron test includes three parts: grounding resistance test (cold/hot state), leakage voltage test, and leakage current test.
1. Grounding resistance test of electric soldering iron in cooling state:
In the absence of power, contact one end of the multimeter probe with the grounding terminal of the power plug and the other end with the tip of the soldering iron to test the data;
2. Ground resistance test of electric soldering iron under heating state:
Plug in the power supply, turn on the soldering iron, and connect one end of the multimeter probe to the grounding terminal of the battery, while the other end is in contact with the testing board that contacts the soldering iron. Measure the results;
3. The leakage voltage test and leakage current test of the electric soldering iron are similar to the resistance test method. It should be noted that the multimeter needs to switch gears or adjust the position of the multimeter probe wire when measuring current.
Maintenance methods for electric soldering irons
1. Repair method for soldering iron that is not hot after being powered on
(1) After the electric soldering iron is powered on, it is found that the soldering iron head is not hot, usually due to the power cord falling off or the soldering iron core wire breaking. In this case, the R value of the multimeter can be used × If the pointer of the multimeter does not move at both ends of the power plug measured at the LKN gear, it indicates an open circuit fault.
(2) Firstly, check if there is an open circuit in the lead of the plug itself. If not, remove the bakelite handle and use a multimeter to measure the two leads of the soldering iron core. If the multimeter pointer still does not move, it indicates that the soldering iron core is damaged and should be replaced.
(3) The resistance value between the two leads of a 35W internally heated soldering iron core is 1. Around Skfl, if the measured resistance value is normal, it indicates that the soldering iron core is good. The fault occurs in the power lead and the plug itself, and most of the faults are due to open circuit in the lead. It is necessary to replace the soldering iron core, insert a new soldering iron core of the same specification into the connecting rod, fix the lead on the fixing screw, and tighten the wiring post. At the same time, pay attention to cutting off the excess part of the soldering iron core lead to prevent a short circuit between the two leads.
2. Maintenance methods for live iron heads
(1) The reason for the electrification fault of the soldering iron head is not only that the power cord is wrongly connected to the grounding wire terminal, but also that when the power cord falls off the soldering iron core terminal and touches the screw of the grounding wire, causing the soldering iron head to be electrified.
(2) This type of fault can easily cause electric shock accidents and damage components. To prevent the power cord from falling off, it is necessary to regularly check whether the crimping screw on the electric soldering iron handle is loose or missing. If there is any looseness or loss, it should be prepared in a timely manner.
