LONG LIFE BATTERY-internal heat type nozzle iron
internal heat type nozzle iron
When making the electronic circuits in this book, only rosin core solder strips can be used.Another kind of solder strip that can be bought in hardware stores or white iron shops is acidic. The core of this solder strip contains acid, which can only be used for soldering lead skins. The acid core solder strip will damage electronic circuits and components.The acid core solder with decay candle will decay the lead wires of electronic components to produce virtual solder, and the copper foil strips on the printed circuit board will also gradually be eroded away by decay candle.Virtual welding will break the connection of the circuit and lead to high resistance at the solder joint.Poor soldering of electronic circuits can cause many problems.Virtual welding hinders the flow of current and sometimes produces detection in audio circuits.Virtual welding can cause poor circuit connection or open circuit.The reason for the virtual welding is usually that the components are not heated to the proper temperature before dropping solder onto the solder joints prematurely. welding head only heats the solder without heating the joints to be welded.
3 correct welding technology
When making electronic circuits, follow the correct welding procedure.The finished product thus finished has stable electrical performance and reliable work.Its operation steps are as follows:
( 1 ) The welded components shall be cleared of all sundries or debris.For example, scrape off the insulation outside the wire and wipe off grease, tar or other oil stains.
( 2 ) Before welding, the component leads that need to be welded on the same solder joint are tightly wound around each other, so that there is a firm mechanical connection between the components to ensure that the components do not move.
( 3 ) The soldering iron head should have a proper welding temperature, so after the power supply is turned on, it should wait a few minutes before welding.
( 4 ) The soldering iron head should be placed on the soldering point, not on the solder.When the lead wires of the components are wound around each other, the soldering iron head is first placed on the soldering point and heated so that the lead wires of each component reach the same temperature.
( 5 ) Then put the solder on the soldering point instead of the soldering iron head so that the solder can freely contact around the lead of the component.When the soldering point is heated to almost the same temperature as the soldering iron head, the soldering tin is heated by the lead wires of the components, so that the soldering tin flows to each part and contact point of the winding lead wires.
( 6 ) Use the right amount of solder. Too much solder will result in virtual soldering.
( 7 ) Remove the soldering iron after the solder flows into the solder joint.Make sure that the components do not move during welding.If the component is moved at this time, the gradually cooled solder on some parts of the solder joint will become cracked or loose.
( 8 ) It will take about 20 seconds for the solder to cool completely.
( 9 ) After welding, twist the components on the welding spot to ensure there is no virtual welding.
( 10 ) Check the appearance of the welding spots to see if there are any spots with dark or spherical surface.Good solder joints have a smooth and shiny appearance.A solder joint with a dark and muddy surface and a rough surface is often a virtual weld.
The above steps may sound complicated, but they will gradually get used to as the welding work increases.As a matter of fact, only after a few hours of practice can a solder joint be welded in a few seconds.The key is to put the soldering iron head on the solder joint, not on the solder joint, and to allow the solder to flow into the gap of the solder joint before removing the soldering iron.Remember that only a small amount of solder can be used during welding. Too much solder will result in virtual welding.This is because the cooling rate of solder at different levels in the solder joint is not consistent.When welding head warms a large drop of solder, it can only melt the outer layer of the solder, while the inside is still relatively hard. However, it is important that the inside of the solder joint is firmly mechanically connected to the electrical connection because the solder does not have enough mechanical strength to form such a mechanical connection.It can only be used as an electrical connection, not as a mechanical connection.For example, if two wires are welded together with solder, the general mechanical stress will cause the weld to loosen and crack, because no proper mechanical connection with certain rigidity has been made at the weld in advance.It must be reiterated once again that solder can only form electrical contacts, and the components on this solder joint must be firmly connected with the machine.
In addition, the welding speed is also very important even if a low-power internal heat soldering iron is used.Some solid-state circuit devices used in making the circuits in this book will be damaged if the heating temperature exceeds the limit temperature of the device during soldering.Before the reader can master the correct welding method, he can practice the welding technique with some heat-resistant devices ( e.g. resistance, capacitance and even winding two wires ) until he is proficient.When welding, speed should be faster.Because the longer the welding time is, the more heat will be applied to the device.Therefore, it is necessary to have a proper welding speed to avoid overheating and damaging the components.
When soldering heat-sensitive electronic components, appropriate heat dissipation measures are often taken to dissipate heat or absorb heat. The pointed-nose pliers are a very good radiator. Clamping the jaws of the pointed-nose pliers on the leads near the component shell can dissipate heat well, as shown in Figure S - 16.The heat will be conducted up the lead from the welding point to the pointed-nose pliers, which will absorb most of the conducted heat, thus preventing a large amount of heat from being conducted to the shell of the component.Crocodile clips and special heat sink clips can also be used for thermal protection.The advantage of using this tool is that it frees up the producer's hands for better welding.When using heat dissipation clips, be careful not to clip on component leads that are too close to the welding points, or heat dissipation will quickly lead to virtual welding.The heat dissipation clip is preferably clamped on the lead as close as possible to the component package.Figs. 3 - 17 show the heat dissipation clip clamped on the transistor lead.
It must be pointed out that it is most important to master the correct welding technology when making electronic circuits.Do not rush to make circuits until you have mastered the correct welding technology, and do not rush to do so.In mastering the welding technology, it will take a few more minutes to save a lot of time in the future to check the fault, re-weld the circuit or replace the damaged components due to heating.
Yan 3 - 17 Heat Dissipation Clip on Transistor Lead