I have a stable dc 12 volt input 2 Amps and i want to make 6 different exports out of it like a power suply.
I would like to make the six reduced outputs out of it : 12v as i get it from the input,9v,6v,5v,3v and 1.5v
I also like to use some easy and not complicated way such as resistors since my input is stable, so if i want to make the 12v into 9v out in the first output it would go something like 10ohm resistor as 1st and 30ohm resistor as second and my output will be 9v.
Then i just follow the procedure of the 2 resistors then to lower the 9v into 6v and so on to create the outputs i need.
If i am correct and it will work fine do i have to choose a type of specific resistors and ohms and does this affect my amps and volts or it doesnt matter at all since the Vs R1 and R2 and Vout maths are ok like the above ? I can even use for example R1=1ohm and R2=3ohm to get the 9v output but does this makes any difference ?
Thank you in advance for any answer, help or advice on it
Answer
No, this will not work.
Imagine if you have your 10 ohm and 30 ohm setup, and you hook a light bulb to the output that has an on resistance of 8 ohms.
The 8 ohms is then parallel with the 30 ohms and creates a 6.3 ohm resistance, and your supposed 9V power supply exhibits a voltage of 4.6V.
In other words, the load you put on the power supply will change the current drawn, and since the voltage drop across the top resistor will change according to current then your voltage will always change depending on the load.
You will need to use voltage regulation of some sort. Simple voltage regulators are available that are as easy to use as the resistors, though, so you should look up simple power supply designs using voltage regulators.
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