Diodny Bridge – one of the devices, most widespread in electronics, intended for straightening of alternating voltage. As a result of transformation at the exit of the diode bridge the pulsating stress twice of bigger frequency, than on entrance turns out. Practically any power supply unit of modern electrotechnical devices does not do without such scheme.
Instruction
1. Choose type of the diode bridge. It can be executed from separate diodes or in the form of monolithic diode pack. Such assembly has advantage as it is simple when assembling on payment, however in case of the output of the diode out of operation it cannot be replaced with another. It is necessary to change all scheme.
2. In the absence of the ready diode bridge collect it from four diodes. The diodes calculated on current intensity 1 A and voltage of 1000 V will approach. Calculate the necessary power of the bridge by means of multiplication of limiting current by ultimate stress, with double stock on power.
3. Example of calculation: there is diode bridge on 1000 V and 4 A. Power of loading will be 1000х4=4000 W. Taking into account the doubled "margin of safety": 4000/2=2000 W (2 kW). Similarly power and for other models of vypryamitelny bridges is considered. By drawing up the diode bridge consider that through each of diodes about 70% of public current, otherwise, if in loading current 4 A proceed, then in the separate diode of the bridge it will make 3 A.
4. For cooling of assembly of the bridge (it is admissible, you mount the bridge for automatic welding semiautomatic device), use aluminum radiator about 800 quarter see. Prepare radiator surface: drill openings, cut thread for assembly fastening. Use heat-conducting KPT-8 paste for increase in heat emission.
5. Fix diode pack on radiator surface by means of M6 bolts, using at the same time tubular key.
6. Unsolder the scheme the copper tire. To Shin of 10 quarter of mm in size solder to conclusions of assembly and the tire of 20 quarter of mm in size for current entrance exit chain. Surely solder the tire to conclusions of diode bridges if to connect bridges without soldering (terminals), the ends of conclusions will be strongly heated. The diode bridge, small by the sizes, comfortable for its configuration in the body of automatic welding semiautomatic device has as a result turned out.