You can use this 5V to 12V converter circuit to easily get 12 volts from a 5V similar source.
This is based of the theory that inductor holds current and passes in opposite direction. This is a DC to DC step up converter, also known as boost converter and it has efficiency of 60-80%.
As the efficiency of this circuit is not very high, so we can’t use it for large projects, which needs max power.
We can use it for low power consuming models. Like 12 Volt 3 watt model, which require 250mA current, and since we are giving 5 volt as input, we have to spend around 720mA current with 80% efficiency.
In this circuit we are going to put DC pulse through an inductor and take the boosted current from the inductor when it’s off. We are using a general purpose high current MOSFET, P55NF06 here which is mostly used in inverters.
And for making the inductor coil, we need to follow the below chart for some expected voltage range.
- 6v to 12v @ 1Amp : 80 turns of 24swg wire in a 0.5mm ferrite core
- 6v to 12v @ 500mA : 60 turns of 36swg wire in a 0.5mm ferrite core
- 12v to 18v : 120 turns of 24swg wire in a 0.5mm ferrite core, and so on…
If we are using it for circuit applications, we need to attach the zener diode at output, and if we are going to charge a battery, no need of zener diode.
The circuit below is shows 6 volt input, however you can use it with input voltage range of 4.5 volt up-to 9 volt.
One thing to remember, we can increase and decrease output voltage by altering the value of the zener diode, but increasing much voltage will produce less current and less efficiency, and also we have to attach a larger capacitor there in output.
We are driving this mosfet with high frequency square pulse generated by a 555 timer I.C. High frequency for higher efficiency, as current loss within inductor will be less. This is a voltage converter, not a constant current output converter, so we’ll get small ripples at output.
The above circuit diagram is of 6Volt to 12Volt converter. Change zener diode value to change voltage yourself.
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