My criticism is send to some guy´s that appears to be purist for some rules, but may ignore that not only offline sets are dangerous. Some stuff work more that 160/310VDC (110V rectified or doubled, or from 220V mains), and use large caps that store much dangerous voltage and currents than the above mentioned, as an example, tube amplifiers. Please, a bit of criteria in the posts.
My friend, my suggestion is close the damn thing before you cause some serious damage.
any small error on your part and you wont/cant post on this forum again.
I am more than aware that most people on this forum do have hands on knowledge and know what they are dealing with.
but judging from your previous comments you DONT.
(I agree with macboy)
Any offline SMPS deals with main rectified voltages of 380-420V DC for a 220V and about half that for a 110V nation.
Its sheer stupidity if you think you can poke around without know what you are dealing with.
Its no different from having a death wish.
A request to the moderators :-
I know that this topic has been closed and reopened but i believe that it should be closed.
We cant teach the OP about HV safety online and i d rather not read about any mishap thats happened because of operator handling
( i m pretty sure none of the members here would)
any small error on your part and you wont/cant post on this forum again.
I am more than aware that most people on this forum do have hands on knowledge and know what they are dealing with.
but judging from your previous comments you DONT.
(I agree with macboy)
Any offline SMPS deals with main rectified voltages of 380-420V DC for a 220V and about half that for a 110V nation.
Its sheer stupidity if you think you can poke around without know what you are dealing with.
Its no different from having a death wish.
A request to the moderators :-
I know that this topic has been closed and reopened but i believe that it should be closed.
We cant teach the OP about HV safety online and i d rather not read about any mishap thats happened because of operator handling
( i m pretty sure none of the members here would)
Ouch ... that hurt.
In any case I sound more scatter brained than I am cos by the time I post back after my foray into the electronics of these things several hours have passed, and I have played with 20 other things, motorcycles, people's carbs (I set up carburetors on people's bikes) my neighbors cats (they keep getting in the garage and getting lost under and behind stuff and meowing like the dickens) and likely a few more things around the house ... lawn, A/C etc etc. I tend to post a lot less than I do work on for brevity's sake.
Rest assured I have yet to give myself anything more serious than a headache and that too could be the beer I'd have drunk ...
I've fixed several amps including some that really were suffering from unheard of problems including several home theater amps ... really I am capable of not shocking myself ... Having said that, I suggest no one follow me blindly ... I may have just the luck of the devil ...
Cool.
Srinath.
In any case I sound more scatter brained than I am cos by the time I post back after my foray into the electronics of these things several hours have passed, and I have played with 20 other things, motorcycles, people's carbs (I set up carburetors on people's bikes) my neighbors cats (they keep getting in the garage and getting lost under and behind stuff and meowing like the dickens) and likely a few more things around the house ... lawn, A/C etc etc. I tend to post a lot less than I do work on for brevity's sake.
Rest assured I have yet to give myself anything more serious than a headache and that too could be the beer I'd have drunk ...
I've fixed several amps including some that really were suffering from unheard of problems including several home theater amps ... really I am capable of not shocking myself ... Having said that, I suggest no one follow me blindly ... I may have just the luck of the devil ...
Cool.
Srinath.
To your original question, it looks like the circuit board with the "large transformer" is a Power Factor Correction (PFC) circuit board. It takes the off-line AC power and switches it through a large inductor to generate ~420VDC, plus another circuit generates some low voltage "house-keeping" voltages like +5 & +12 at low currents. Research PFC on Google for more info.
The other "small transformer" board takes the power corrected 420VDC and switches it (Google SMPS) through the "small" transformer to generate the 42, 12, 5, 3.3, etc. DC voltages the server or network equipment runs on. This is a pretty conventional SMPS - albeit high power - circuit with rectification, feedback, filtering, etc.
As previously noted, there are LETHAL voltages present inside this chassis. Use extreme caution when handling these parts. Even unplugged and sitting for days, there can still be voltages stored in the filter caps (though the bleeders should eliminate them). And unless you understand all of the intricacies, and dangers, of high-voltage PFC and SMPS circuitry, I would not try to work on them or modify them; just close them up and stay safe. And since you're asking these questions, I'm glad you're learning, but please be safe.
The other "small transformer" board takes the power corrected 420VDC and switches it (Google SMPS) through the "small" transformer to generate the 42, 12, 5, 3.3, etc. DC voltages the server or network equipment runs on. This is a pretty conventional SMPS - albeit high power - circuit with rectification, feedback, filtering, etc.
As previously noted, there are LETHAL voltages present inside this chassis. Use extreme caution when handling these parts. Even unplugged and sitting for days, there can still be voltages stored in the filter caps (though the bleeders should eliminate them). And unless you understand all of the intricacies, and dangers, of high-voltage PFC and SMPS circuitry, I would not try to work on them or modify them; just close them up and stay safe. And since you're asking these questions, I'm glad you're learning, but please be safe.
I will be careful, but see I've worked with these things since the early 90's. I am a software engineer by trade, and have spent countless hours with these buggers, and have seen em apart plenty of times while the true hardware guys poked around inside of em. That is how I ended up with 5-6 of these without even trying ... it was one of those ... hey you, "this works fine, we need it outta here, you're sitting in this room, you do your part and haul em outta here ... " to which I say something like ... but, but, but, I am on this motorcycle ...
Anyway I will be careful guys, thanks.
Cool.
Srinath.
Anyway I will be careful guys, thanks.
Cool.
Srinath.
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