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  1. Damien

    2n3055 saturation

    Hi there I am wondering if someone out there knows how much the 2n3055 requires to be fully on (saturated) Having a look at the datasheet is says - Collector−Emitter Saturation Voltage − VCE(sat) = 1.1 Vdc (Max) @ IC = 4 Adc Does this mean that it is saturated at 4a 1v? What if the voltage...
  2. Damien

    Blown 2n3055 transistors

    http://electronics.stackexchange.com/questions/72849/how-can-i-get-more-amps-from-a-voltage-regulator Would this be the way to go to get more current at the base of those 2n3055's? Also if I have them paralleled (The 2n3055's) Does that mean that I need a total of 8 amps to completely saturate...
  3. Damien

    Blown 2n3055 transistors

    Haha I've posted a few times but the further I look into this the more questions I have it's like a can of worms. I know Shrtrnd mentioned that I should replace my 2n3055's with the newer MJ15003's but they are literally 15 times the price. Ebay has them listed for $15 and the 2n3055's for $1...
  4. Damien

    Blown 2n3055 transistors

    No idea on the output as this transformer has no info stamped on it apart from voltages. I'm hoping it's above 10 amps on at least one of the rails? o_O What if I ran both rails in parallel this would essentially double my current output right? If I set both rail at the same voltage with the...
  5. Damien

    Blown 2n3055 transistors

    Shrrnd: That was my guess to so I removed the cap but nope, still doing the same thing so I ripped out the regulator and swapped it for a 7805 (5 v linear regulator). I would have used a another 12v one but didn't have any lying around so just thought I'd try the 5v as I know my meters and...
  6. Damien

    Ideas for a school experiment?

    Tesla coil! You'll be the most popular kid in school! =D =D ...or shunned for being weird. =( Could go either way. Proceed with caution. =/ Oh also maybe get everyone to sign an insurance waver before you power the thing up.
  7. Damien

    Blown 2n3055 transistors

    Thanks for that shrtrnd I will rip these ones out and put some MJ15003. I might get the rest of the circuit just operational first & then upgrade the MJ's when I'm ready to put it into service. Any opinion as to why that L7812cv for the fans,meters and led circuits is dropping voltage on startup...
  8. Damien

    Blown 2n3055 transistors

    Oh one question I forgot to ask - I have a separate circuit running mounted on the same protboard. It's a l7812cv voltage regulator. It's wired up correctly as I use these quiet a bit for u.s.b chargers (l7805cv for example). I have this regulator in service and have it wired to some indicator...
  9. Damien

    Blown 2n3055 transistors

    Thanks for your input guys. As you can see I have them mounted on large heat sinks (it's actually duel rail) I'm using the heat sink as the collector conductor (2 transistors per rail & heat sink cut in half down the middle as you can see). I can understand how back emf could be a problem with...
  10. Damien

    Blown 2n3055 transistors

    Hey guys I'm a little stumped as I just put my power supply together which long story short consists of an lm317 driving two 2n3055 pass transistors. These 2n3055's are rated for 15 amps each and they're paralleled so I should theoretically get 30 amp handling capacity. I tested it out last...
  11. Damien

    5v linear voltage regulator design problem.

    I'll scan a copy of a written circuit if this doesn't make sense as it's a very basic circuit. 12v in - Pin 1 Common earth - Pin 2 5v out - pin 3 A small cap between ground and 5v output pin to smooth out waveform.
  12. Damien

    5v linear voltage regulator design problem.

    The reg that I'm using with a big arse heat sink will run a g.p.s doesn't seem to want to charge the battery in it, not enough current?. Will also only charge a vape battery when g.p.s is unplugged. My g.p.s uses 5v a amp (5 watts) Will this reg be able to throw more than 5 watts somehow? Is...
  13. Damien

    5v linear voltage regulator design problem.

    All this heat sinking required, surely this is inefficient. For low current needs (below a couple of amps) Would a dc to dc buck converter be better? I am by no means ready to step into p.w.m world just yet but just out of interest, are they more efficient or just as at low currents? I saw an...
  14. Damien

    5v linear voltage regulator design problem.

    Cool thanks for that, I'll check out what the draw of all my gadgets are before making a decision on regulator sizing. I usually take opiates for pain in the form of codeine (panadine forte) or if it's more severe like today endone which is also a synthetic derivative of opium and use...
  15. Damien

    Electrons

    Hey hey Just doing a little research on electrons to try and understand how a fluorescent light tube works. From what I can fathom, an "ion" is an electrically charged group of atoms that can be either negatively charged or hold a positive charge. A "cation" A.K.A "positive ion" is a...
  16. Damien

    5v linear voltage regulator design problem.

    Yup, not comming up for you? I can see my replies throughout the quoted message.
  17. Damien

    5v linear voltage regulator design problem.

    I presume it would be positive as someone mentioned that they didn't use negative ground until after 1950 so it was just a tounge in cheek question. ;-) Yep, miss typed I meant lm317 variable voltage regulator. Did my back in so very high on pain killers and anti-inflamatory medication. I...
  18. Damien

    5v linear voltage regulator design problem.

    I apologize as I have provided the wrong datasheet. The regulator I used is in fact the 7805 not the 7905. So 7805 no workies with 1950 studebaker? =P Ok so regulator's are different than transistors. What about the lm783 regulator? Is this not a mosfet transistor? The regulator heat sink was...
  19. Damien

    5v linear voltage regulator design problem.

    Nope wiring was all correct just checked it then. Sooo... Pin one = 12v input source Pin two = ground Pin three = 5v output Would the huge gap in voltage cause all that heat to dissipate? I am thinking perhaps I should go down the switching mode regulator path but surely these little l7805cv...
  20. Damien

    5v linear voltage regulator design problem.

    Soz Duke just got back from trip, exhausted might draw up a schematic and scan it tomorrow with scanner. Is there any circuit drawing programs that are good so I don't have to draw them by hand? Not that I mind it would just be quicker with a mouse perhaps. The 3 regulators were all destroyed...
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