Boosting Voltage from 7V to 12V

[devilfrmheaven]

Hi All,

I have a voltage source that may vary from 7V to 16V 5Amps

Is there anyway I can get 12V 5 AMP output from it?

Thanks in Advance for the help.


Regards,
Devil

 

[Eshal]

Hello
Are you mean by DC voltage? Then yes. Switching regulators in the configuration of boost converter or regulator is the solution.
Are you mean by AC voltage? Then answer is also yes.

You application?

Regards
Princess

 

[devilfrmheaven]

The application is for my dynamo and headlights

Hello
Are you mean by DC voltage? Then yes. Switching regulators in the configuration of boost converter or regulator is the solution.
Are you mean by AC voltage? Then answer is also yes.

You application?

Regards
Princess

 

[Eshal]

Oh yes. Then you need a DC to DC converter.
There are DC to DC converter ICs are available. You can buy. Many suppliers are available world wide.

 

[sonicsmooth]

Not necessarily.

For the supply, your worst case condition is 7V x 5 A = 35 Watts maximum supply.
But you require 12v x 5A = 60Watts.

So Even if you had a 100% efficient Dc-Dc converter, your input needs to supply 60 Watts.

 

[BradtheRad]

To step up 7V (at 5A) to 12V, it is theoretically impossible to obtain 5A output. You'll be lucky to get 2A output at 12V.

You'll need to use your entire dynamo output, at 100% duty cycle.

About the most efficient method is a voltage doubler, consisting of 2 capacitors, alternately subjected to 7V via an H-bridge.



If you were to use a switched-coil converter, it will need to contain 2 or more interleaved units.

 

[Eshal]

To step up 7V (at 5A) to 12V, it is theoretically impossible to obtain 5A output. You'll be lucky to get 2A output at 12V.

sorry. I didn't get your statement. Can you elaborate it please? why is it so?

 

[BradtheRad]

sorry. I didn't get your statement. Can you elaborate it please? why is it so?

Hi, as we know, we can only get as many watts output as the amount of watts input. If we have 7V at 5A, then that makes 35W. (Although perhaps the 5A applies when the output is 16V. It is not clear from post #1.)

Hence if we want 12V output, we can expect a maximum (theoretically) of 35W / 12V, or 2.9 A.

The process of conversion itself sacrifices a few watts. This is unavoidable. So the best I was able to obtain in theory (simulated) was 24W.

 

[Eshal]

You are right. This is power conservation as you are talking about. But I think we can get further power. Let say if we have 2V at 1A input then we can use voltage doubler for voltage boost and current booster circuit for current increment. Is it not the way sir?
There is always a way. So why not?

 

[Dan Mills]

Because (mass)energy is always conserved and thermodynamics says that no conversion process is 100% efficient, this is highschool physics.

A voltage booster will always produce lower output current then its imput current such that (Vout * Iout) < (Vin * Iin).
A current booster will always produce a lower voltage output then its input such that (Iout * Vout) < (Iin * Vin).

Now if your machine could produce say 7V @10A dropping to 16V @ 4A then things become possible, Linear for example have a 4 mosfet, single inductor buck/boost controller that would easily give you your 12V output @5A under the above constraint.

Regards, Dan.

 

[Eshal]

I agree with you Dan Mills.
Very nice answer. Now I have also understood Bradtherad's statement

Thank you

 

[pratomer]

for that u will require external power supply to boost the voltage and current