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Everything posted by flippityflop

  1. the datasheet says it has an output of 1A, so i thought there might be a chance it'll try to compensate to maintain that current. though you are right, it'll violate ohm's law.
  2. say i have a linear voltage regulator set at 9V, and current the and is 1A, which is constant and i can't change. and i'm using it to power a small device that runs at 9V, but on average only consumes 350mA. is there a good possibility that the linear regulator will overload the device with current and possibly even break it? the linear voltage regulator i'm talking about here isn't about the 0-30V, 0-3A power supply from the projects page, actually i've only barely started on that one yet.
  3. no. there are no subliminal messages ( >"breakdown" <-- ??)... so if hesitant, please still reply.
  4. i know this is a stupid question but i'll ask away anyways... are there any diodes that instead would have a specified *current breakdown* rather than a voltage breakdown? i know it's stupid coz the current would have to flow first to know the amp to know when it should break, but the diode is already hindering that flow in the first place. in an analogy of transistors, diodes are dependent on voltage, as are FETs. the BJTs are dependent on current.... so are there any diodes dependent on current too?? (though the analogy is somewhat forced, as diodes actually work on the same principles as
  5. instead of N*L, it's L/(N^2) and L = 3.742mH. sorry. my bad. can't even do simple algebra.
  6. well, nobody replied to that suggestion, if silence means "yes", then i suppose no one's objecting. actually, instead of 2 permanent magnet toroidal core, i think i'll just share 1 core -- each polarity winded in reverse. that should save space and be more efficient. i might also change from a toroidal core to a pot core. there should be several companies out there that specializes in general ferrite (both soft and hard) that can make me a pot core with the composition of a hard ferrite and permanent magnetization with little overhead. i'll try the company that cheaply sold me 4 blocks of mag
  7. the first section, the rectifier, since it's gonna be general purpose, i decided to be a capacitor-input filter. i already decided on 12mF on C1, since that's what i already ordered online (and the best i could get for a hefty $16, EDIT: but worth any penny! digikey, i love you! i'm sucking up coz you're my single go to place for electronics and your prices are great!). i have a 470uF capacitor, which i salvaged years ago, so i'll use it for C2. using the resonance formula: L = 1/((2*pi*60 Hz)^2 * 4.7 * 10^(-4) F ) L = 14.97 mH. i'm going to be using a toroidal inductor whose core is a
  8. thnx xristost! i'm thinking more of using 3 different PCBs for this design rather than print it all in 1. 1) rectifier, C1 section -- this plugs in directly to my oversized transformer and goes to a separate enclosure box i'll be putting the main PSU. this is done so that it can be reused for any future projects... i hope my 12mF capacitor can handle any general purpose rectifying 2) LM317, LM337 section -- like you said, xristost, these are the reusable parts, if i want to add several more outputs. 3) TL082P A/B sections and 2N3055 -- so i MIGHT be able upgrade them to a switch mode regul
  9. i know this is a stupid question, but i'll go right ahead... i understand that's IC1A, IC1B, and 2N3055 mainly are regulating the voltage and current, can i swap them in the future with switching mode components/assemblies to increase efficiency??
  10. i know this is a stupid question, but i'll go right ahead... i understand that's U2, U3 and Q4 mainly are regulating the voltage and current, can i swap them in the future with switching mode components/assemblies to increase efficiency??
  11. i'll be purchasing 2 of each components, maybe i'll 1.) build a second output or 2.) maybe i'll find a way to increase amperage (wherein past a level, the voltage has to start going down, or increase voltage (wherein past a level, the current has to start going down)... there is only as much power as i can draw, even for my over sized transformer... whichever one is easiest for me...
  12. about the need 1N400x's i found out that i had one that i salvaged. - at the time of this reply i already have and saw the maximum reverse currents.
  13. so i need 4 1N4004 diodes but all i got are 1N4002, 1N4005 or 1N4007's, would they do? so, just to expand the question are there any site that post comparatively different electrical components, but are electrically (functionally) almost identical that in most situation, they can be interchanged? or when a certain manufacturer introduces a component into the market and the component gets named, do all other manufacturers just follow suit and for anything they introduce that are similar to the previous component, they name the same?
  14. i just like pushing the envelope, even if i hardly know anything about the theory (software, not hardware, really is my specialization). alright, i'll be building your ver 2... i'd like to have 2 different outputs, with that, i suppose that you can always share the rectifier. but, i was wondering what other sections can be shared if i were to do so?
  15. btw, why isn't a PMIC (Power Management IC) a better solution other than using the more complex designs found on the web that doesn't use PMIC? is it heat dissipation, lower ripples, better control, what?
  16. i've always wanted a variable power supply; not just for testing... possibly powering my other projects, some of the electrochemistry that i dabble with, charging my lipo and lead acid batteries, etc, etc... problem is, good ones are in the $90-$150 range (even on ebay) and the cheap-ass as i am, i'd rather build myself one, as i think i've salvaged/collected enough components throughout the years. i first set my eyes on the 0-30 VDC STABILIZED POWER SUPPLY WITH CURRENT CONTROL 0.002-3 A (http://electronics-lab.com/projects/power/001/index.html) from the project section... so mods, no need t
  17. i wasn't sarcastic when i said that. anyways this discussion's gone too long than it need be. locking it now.
  18. yep just looked the little bugger up... it's tiny. but, i don't want to add another task in my to do list, that is, to learn to program PICs... and i don't have a PIC programmer ???. i also have no experience at all to wiring microcontrollers.. (i'm not even that sure as to what pull-up resistors does). at least my last design has the functionality of being adjusted manually and it turns itself off (huh!! take that!). just ordered my parts lists online (still don't know what to use for the unknown component) whole thing cost 15 frickin dollars. that's shipping not yet included. ridiculous.
  19. well, you can start thanking me by saying as to what components can i use for mystery components 1 and 2?? no, seriously i don't know. ???
  20. yeah, but what about using more expensive components??.... see i'm using this to play around with electrolysis (when i get too impatient, i remove the resistor on the electrode, and since it's a very ionic solution, the current definitely goes beyond 2A). so, i've broken 3 scavenged wall warts so far, so now i'm determined to have a heavy duty power supply with current limiting capabilities; and i'm sure it's gonna be indispensable in the future.
  21. last, last, last question... what possible component could i use for unknowns 1 and 2 in my updated design?? preferably an FET
  22. i see... right now, power efficiency is just a plus, it's not like i'm gonna leave it for hours and hours on end. if heat dissipation is really an issue, a better solution (than having a big-ass common heat sink) probably would be to add more redundant components to distribute the load.... or substitute more expensive components.... guru, do you think that would work??
  23. i see... is that project based on switching-mode? and in general, would power supplies based on switching-mode deliver higher current and even better voltage range?
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