The welding machine is necessary for electric welding of products from ferrous metals. The devices released by the industry are not always available at the price therefore it is sometimes reasonable not to buy the device and to manufacture it by own efforts of simple elements. To make the invertor unit for welding, it will be required widespread parts, the majority of which can be taken from the old television receiver.
1. Study the scheme of the welding machine. The advantage of the provided decision in simplicity of design and lack of scarce parts. Correctly mounted device practically does not demand additional debugging.
2. Make the list of parts of the device, being guided by skeleton diagram. Prepare element base. Use for production of the device of part which can be got in workshops on repair of the teleradio equipment. Before sealing elements in the scheme, make sure of their serviceability.
3. Execute throttle of L1 on steel magnetic conductor or pick up the ready device. Make winding of throttle of PEV-2 wire, having reeled up 175 rounds.
4. Use the K78 condensers which were widely used in television receivers. The optimum operating voltage of condensers has to be not less than 1000 V. In the absence of elements with the required face value use several condensers, having brought their total capacity to the necessary level.
5. Pick up several low-power trinistor of the KU221A brand. Do not try to replace them with one trinistor of big power as it will lower operating frequency and will lead to emergence of loud unpleasant sound when welding.
6. When mounting the device sustain necessary gaps between magnetic conductor and windings of the transformer. For this purpose use plates from textolite, having put them in windings. It is required for ensuring electrical safety and reliable cooling of the welding machine with air flow.
7. Attach the transformer to the basis of the welding machine two or three brackets. Bend brackets from copper wire with a diameter not less than 3 mm.
8. Make payments of the device of the foiled textolite 0.5-1.0 mm thick. In each payment do four narrow cuts for reduction of loads of conclusions of diodes.
9. Establish all nodes of the welding machine after their assembly on the basis made in the form of plate of micarta 4-5 mm thick. In the center of the basis cut through round window for fastening of the fan. Protect the fan grid. Surely provide air gap between magnetic conductors.
10. Bring the SA1 toggle-switch handle, LEDs, the handle of the variable R1 resistor and clips for cables to face side of the basis.
11. Place the mounted device in the casing made of the sheet viniplast or textolite. Wall thickness of casing has to be not less than 4 mm.
12. The holder for electrode equip with the button in the place comfortable for inclusion and switching off of the device. Provide reliable isolation of the button and the cable connected to it.