Electronics Projects, Electronic Fuse Circuit for Power Supply article
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Electronic circuit current fuse is welcome especially in structures of power resources and in particular in power assembled circuits. Classic fuse tube fuse in the wrong PCBs under test is not enough save, sometimes quite expensive components from short-circuit current than the fuse blows, most semiconductor devices has been destroyed long ago. Therefore, it is preferable to use an electronic fuse which is of the order of up to a hundred times faster, and in particular can be set current constraints from the smallest streams flowing into the load. Everyone around immediately say, when there are so many benefits why is not this insurance is often deployed in power sources, the problem is mainly in cooling power element (transistor BUZ11) during normal situation where the lock is not active heat losses are minimal due to low resistance switching transistor. The situation is changing rapidly in the event of activation of the current fuse, then power transistor becomes serially assigned a resistor in the path of a flowing stream, and therefore the losses it incurred directly proportional to the supply voltage and the set omezovacímu current.
Electronic Fuse Schematic Diagram
Current fuse can be set to the maximum output current (about 10 mA) up to the maximum allowable current of the transistor T1 (BUZ11 – 20A). the fuse is power supply of +5 V with integrated stabilizer 7805, +5 V voltage reference voltage and therefore stability is important to determine the accuracy of the current limit setting, control is performed by the speed 10-precision potentiometer Spectrol 534 companies that We can also replace a pair of simple potentiometers, one for fine and one for coarse adjustment of the current limit. The potentiometer is included on each output variable resistance, which donastavíme minimum and maximum current limit. Current fuse is complemented by a red LED diode Q1, which indicates the emerging constraints current fuse.
Electronic Fuse circuit schematic pcb files download: electronic-fuse-circuit-for-power-supply.rar alternaticve link2