DC Boost Converter

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Introduction: DC Boost Converter

My first intention was to design a DC Voltage boost converter to convert 3vdc to 5vdc so that I could power my iPod or any other device requiring 5 volts to charge.  I read about oscillation circuits and boost converter circuits and combined the two.  My results were staggering when I was able to convert 4.5 volts to over 100 volts by accident.  I decided to post an instructable for this instead, for now. If you have any tips to increase the efficiency or output current please comment below, I appreciate any suggestions.

Step 1: Obtain Parts

All components can be found at RadioShack.
     
     PCB
     3 X 1.5 volt Battery Holder
     L1     RF Choke                   100 micro Henries
     R1     Resistor                      10 Ohms
     R2     Resistor                      51K Ohms
     Q1     PNP Transistor          2N3906
     Q2     NPN Transistor          2N3904
     Q3     Power MOSFET         IRF510
     C1     Capacitor                    .01 micro Farads
     C2     Capacitor                    .047micro Farads
     D1     Diode                           1N4148

Step 2: Place Components

Arrange components as you see here or as close as possible.

Step 3: Observe Diagram

Look through the wiring diagram to see what components need to be connected to what prior to soldering.

Step 4: Solder Components

Solder components carefully to ensure there are no shorts, also ensure all connections are made at all points.

Step 5: Clean Up and Test

Trim component leads and clean solder joints.  Be sure to double check connections to make sure a connection isn't left out.  Hook up battery terminals and multimeter and see what you've got!!!

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    149 Comments

    Hello,

    I'm interested in making this circuit however I don't have a RF choke inductor. Can a regular one work? Also can I use a bc-547 or a 2n2222 instead of the NPN transistor you used?

    Thanks

    Sure, 2N2222 is a better option for Q2 because its current rating (600 mA) is more adequate for the 10 ohm resistor (current up to 400 mA) than 2N3904 (max Ic "only" 200 mA).

    I would like to convert 18VDC 8A to 100VDC 2.5A

    Even at 100% efficiency, no one can boost 18v@8 amps (114 watts) to 100v@2.5 amps (250 watts): Laws of physics, as in energy can neither be
    created or destroyed.

    At 219% efficiency it should be possible ;-) 95% is already possible so why not exceed that. The world keeps on progressing.

    True efficiency > 100% is like a unicorn. it is nothing more mythical and does not exist. Sure, some times we have apparent efficiency that are over 100% but the extra energy comes from something else and was not not accounted for in the apparent figure. thus the difference between true and apparent efficiency

    You realize that's not possible. Energy can't be created nor destroyed. Even 100% efficiency is not possible due to some energy being radiated out of the transistors as heat.

    I have to correct myself, I was assuming continuous output. Watts is a measure of power, not energy. If one needs to get more power then what is put int, it could be done by storing and releasing power quickly over a shorter time. One way this can be done with pulse width modulation the output into on and off duty cycles. spending different amounts of time in each.

    Over the course of an hour, a source voltage of 18v and a load that draws 8 amps will source 114 watts for each second of that hour. sourcing 114 watts * (3600 seconds, 60 seconds in a minute * 60 minutes in an hour) = 410,400 watt seconds( watt second is an expression of energy = joules). With an impossible 100% conversion, 410,4000 watt seconds of energy / 250 watts output means you can deliver 250 watts for just 1641.6 seconds. That works out to about 27 minutes and 21.6 seconds. In a world with perfect efficiency using pulse width modulation, one could convert 114 watts to 250 watts with a 45.6% on duty cycle on his output, and a 54.4% off duty cycle.

    First you will need to setup a tesla coil at 8hz and a very large capacitor (big vat of veg oil). This will be giving you that extra efficiency you unknowingly seek ;p

    Next you will need to go ahead and setup a microwave ray in order to excite helium plasma into their "boson" particle state. Go ahead and hook this up to the big vat o' veg oil. Please note that the built up helium boson waves will need to be calmed in order to extract the energy in 'physical' form.

    Note that these are alpha particles. Do not touch!

    Next you will want to hook up 54 and a half (just chop 'er with a butcher knife) "C" batteries in series. This will give you that 82 volt boost and well as compensate for your missing 106 watts. Should give you a good 4 minutes of power.

    Finally, sit back and enjoy!