DC Voltage tripler

1] you serial 3 or 4 batteries together to get 9 to 12v

2] use one battery and use a converter to convert to 9, 12 v or higher voltage.

the converter canbe an osillator simplely. and rise voltage by a transformer.

thank you for the input, however, for option 1 is not feasible as its cost higher than single cell/battery. I'm looking at option 2, but still could not get a proper circuit that do the job

Just a oscillator with a transiftor.

you only need one transistor, two or three resistors, one capacitor and one transformer as feedback loop. the transformer has one feedback wing and one output wing, which is in propotion to input voltage( primary wing). the ration is output/imput(3 or 4v）

verysimeple.

you can build by yourself.

ok will test out, anyway, i'm thinking of using multivibrator coupled up with diode and cap(for voltage tripling) then boost the current using darlington pair.

regards

sufian

Of cuase multivibrator can do the trick.

but it needs two transistors to build the multivibrator. and if you dont add a transformer couple, you will not get enough power. becase the diode and capacitor double voltagewill only get a small power.

In fact, transformer freedback vibrator is very somple. and can transport larger power to output.

cnpower, that is not the answer requested. I asked (as some others in a similar vein) for a design (using as many transistors of any type that you wish) that would do EXACTLY AS ASKED......

Would you be so kind "as to put up, or shut up!" this means prove it with a working design or back down and admit you do not have such a design....

Neither do the rest of us as this is a delicate area where much specialised knowledge is needed to achieve exactly what is needed.

What is needed, in case you have forgotten, is to use a DC 3 volt 9 amp source to produce a DC 12 volt 2 amp source!! So a highly efficient circuit design is needed.

I feel that you may (as some of us have from time to time) - "Bitten off more than you can chew!", but to continue to just talk in generalities is not helping anyone........

Have a great weekend.

I do not believe it is anywhere near as simple as you say......theoretically yes, but a practical working circuit with all values and semiconductor types as well........

He needs to end up with 12 volts DC at 2 amps (24 watts) from a 3-4 volt supply of max 9 amps.....let us assume he has 4 volts, as at 3 volts, it will not have enough current to my mind....

Assuming a circuit that works at 70% efficiency, then he will be drawing the whole 9 amps from 4 volts. If the circuit is not even that efficient, then he will simply not make it....

Please publish on CR4 for us a circuit that will do this exactly at the currents/wattages needed, I am sure that many of us would really like to see it....thanks in advance for your time and trouble.

you only need one transistor, two or three resistors, one capacitor and one transformer as feedback loop. the transformer has one feedback wing and one output wing, which is in propotion to input voltage( primary wing). the ration is output/imput(3 or 4v）

verysimeple.

Dear cnpower, no disrespect intended, but let me ask you: Have you, ever, built a power supply (not for 2 A output, but for any output)? I am asking because in my work I had to built different custom power supplies (for economic reasons - I spend time and labor, not money). Building them, not even for a 3 mA supply (including the controller) I wasn't able to use a minimum of one transistor and two or three resistors. As Confucius said, the paper will endure anything....

Been visiting the website earlier, however, the simulated circuit regulated to the 12V output rather than triple the output with respect to the input.

Thank you for the help though. I would prefer to use discreet component as they are easier to get.

regards

sufian

With a 3 to 4 volt input voltage, the output is a fixed 11V (or any other voltage, lower than that, with the output current of 2A).

That means that your input might be in that range for a fixed output. If you want a linearly variable output dc-dc converter, you will not get it, surely, with a few "discrete" components.

You need to use a boost controller, with the capability of producing 2A @ 12V out of 3V input (see, the min-max conditions). After that, you will buffer your control voltage (3 to 4V) to the reference voltage of the controller, so to achieve the conversion input voltage delta=1V (4V - 3V) to an output voltage delta=3V (12V-9V). Anyway, it is not a very simple operation, you need to breadboard it. Good luck.

For a few milliamps there are plenty of methods, for 2 amps at 12 volts I personally have not seen any circuits, but hopefully someone else has.....

You will probably need a steady 9 amps at least (depending upon efficiency) to fuel this up to get what you want.....

I have looked around on the web, the lowest Vin that I found for finished products for
25 watt 12 volts output was 5 volts, but mostly above 8 volts is required....as Vin....!

thank you, I'm thinking along the way after visiting the website.

rgds

sufian

You are welcome and best of luck........