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  1. I

    Want to power up my programmer

    Have you considered a DC solution with one 9VDC source, a 5V regulator and a 555 based voltage doubler? You'll only need the higher voltage when burning the PIC and it range is pretty wide so it wouldn't have to be all that well regulated.
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    Facing problem in inverter Design

    Why select the IRFP150N FET?? It stikes me as being major overkill!!! In a push pull primary, the drain amplitude will never exceed 2 times Vin (plus leakage inductance spikes). With good snubbers, or active clamps, you could get away with 30V MOSFET's that have a sub .01 ohm Rds on. If you...
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    Electromagnetic field interference.

    Your observation, that with half charged batteries, you don't have a problem, might be a clue. The motor winding impedance is fixed, so as your voltage falls, so does the current. Current is directly proportional to flux field strength. Where is the 555 located within the system? Is it some...
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    pnp vs npn?

    Talking in terms of positive and negative voltages is a bit missleading.... talking in terms a potentials isn't because that would apply for all cases... for example, if you had -12V and -24V supplies for a circuit... both NPN's and PNP's could be used, not just PNP's. If I was to say.... to...
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    Electricity Meter

    Measuring AC power isn't as straight forward as measuring DC power. Do you want to measure... real power or apparent power or average power or RMS power or real average power...etc. etc. etc. All of these are different and the cricuitry needed to measure them is different as well.
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    DRC and net list

    Yes, "errors" can occur, and happen often with manual routing, but it's the user that defines and sets up the "rules" for DRC.....  Different rules can apply for similar situations... for example: A PCB with a .25" hole in it. If you have the hole drilled, the accuracy of the center location...
  7. I

    mosfets

    A bit more clarification on a few points.............. Gate capacitance isn't the "important" number... "total gate charge" is what will determine how much current is needed to switch a FET on in a particular amount of time given the drain source voltage. Typically, the lowest Rds on is had at...
  8. I

    DRC and net list

    As far as I know, DRC is used in PCB layout, not schematic capture. The layout and schematic net lists can be compared for differences, although, with an "intelligent" package such as PADS it happens "pretty much" automatically.
  9. I

    Simple help with transistors!!

    This is ONLY true if the impedances are the same.
  10. I

    Analog To Digital Converter

    A ground referenced Ammeter?
  11. I

    Auto/deep cell charger

    Ante Do you by chance have the "chemistry" to support that statment.... I'd love to see it!! Indulis
  12. I

    Auto/deep cell charger

    A 220uH inductor is the same as a .22mH m is 10^-3 and u is 10^-6 and n is 10^-9 and p is 10^-12 Once the chemistry of a lead acid battery is depleted, NO AMOUNT OF ZAPPING WILL BRING IT BACK TO LIFE, PERIOD!!! This is a irrefutable fact... the zapper company just wants to sell you some gadget...
  13. I

    Auto/deep cell charger

    Check out the battery section on this website..... http://www.golfcarcatalog.com/phpbb2/ When a lead-acid battery is "gone", it is GONE!! No amount of "zapping" is going to bring it back to life... you can't change the laws of physics!!
  14. I

    Purpose of NPN transistor

    Here is one way to look at transistors.......... Consider a large, tall water tower with a faucet on the side. For a NPN, the water tower is the collector voltage the faucet handle is the base, and the what comes out of the faucet is the emitter. The more you open the faucet (provide more base...
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    Why does a transistor heat when base current is high

    Two reasons come to mind right away......... 1) base current isn't being limited 2) you have a high emitter current with a high Vce
  16. I

    Capacitor Voltage

    Voltage ratings on caps relates directly to the dielectric. Temperature rating will follow ESR and ripple current. ESR & ESL will change with frequency.
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    Purpose of NPN transistor

    Voltages "jump"???? While electrons may "jump" from valence to valence, can you please explain the theory of "-ve voltage jumping" from emitter to collector???
  18. I

    using MOSFET driver IC in a circuit!

    Those resistors make sure the MOSFET's turn off. MOSFET input impedance is very high and a  slight amount of leakage current could turn them on.
  19. I

    Purpose of NPN transistor

    To understand how "they" work, you really need to understand semi-conductor physics including electron bonding at the atomic level. Once you get "that stuff down", terms like... doping levels, majority and minority carriers, etc. will make a bit more sense and you'll know exactly how they work.
  20. I

    Simple help with transistors!!

    The way I learned semi-conductor theory said max output current is determined by input current, not the other way around.
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