Hi all.
I Have been looking at this:
http://diyfan.blogspot.dk/2013/03/ad...-take-two.html
As the title of my post suggests, I am not comfortable about running this circuit with only one 2N3055. Now I may have this wrong but at max dissipation this pass transistor would have to waist 90W of power. (If I am mistaken please correct me) And although the designer states that a "huge heat sink" is needed and "forced air cooling", I am not convinced that is sufficient. so something is telling me I should be using about three times 2n3055 in parallel. On a comment from one builder of this supply he says that he burned three transistors but a reply to this says that is normal with a short. I know very little of what I am speaking and I am just starting out with my hobby. But this tells me there is no short circuit protection, but I though a variable current limiting was there to insure the limiting of current and therefore large current would not be drawn if a short happens, so nothing should be burned up. Until I have studied enough to design and build my own supply, I would like to go with this schematic. Please could I get guidance for any changes or additions that need to be made. Thank you. Jimmiegin
I Have been looking at this:
http://diyfan.blogspot.dk/2013/03/ad...-take-two.html
As the title of my post suggests, I am not comfortable about running this circuit with only one 2N3055. Now I may have this wrong but at max dissipation this pass transistor would have to waist 90W of power. (If I am mistaken please correct me) And although the designer states that a "huge heat sink" is needed and "forced air cooling", I am not convinced that is sufficient. so something is telling me I should be using about three times 2n3055 in parallel. On a comment from one builder of this supply he says that he burned three transistors but a reply to this says that is normal with a short. I know very little of what I am speaking and I am just starting out with my hobby. But this tells me there is no short circuit protection, but I though a variable current limiting was there to insure the limiting of current and therefore large current would not be drawn if a short happens, so nothing should be burned up. Until I have studied enough to design and build my own supply, I would like to go with this schematic. Please could I get guidance for any changes or additions that need to be made. Thank you. Jimmiegin