Probably a simple calculation

[sdieterm]

voltage divider 24vdc to 12vdc

How do I calculate the proper resistor in this scenario? I want to step down from 24 vdc to 12 vdc.

 

[Ante]

step down resistor 24vdc to 12vdc

You need to know the loadcurrent, then its Ohms law!

 

[jorgito]

Hello

It seems that you have a lot to learn...
Here are a couple of posible "solutions" to your problem>

1.- Make a series connection of two 0.12 Ohm and connect the free ends to your power supply. The junction point will have 12 V measured from any other end. (Your power supply must source some 100 Ampere)

2.- Make a series connection of two 12 MOhm and connect the free ends to your power supply. The junction point will have 12 V measured from any other end. (Your power supply must source some 1 microAmpere, but you hardly can measure the 12 V, because your test instrument will distort the circuit)

As Ante said, if you want to reduce the voltage on the load using a single resistor, you must specify its current consumption, and the voltage will vary if load current is not constant.

Please do not attempt to build any of the proposed circuits, specially the first.

Hope this helps and best regards!

 

[engr_najam]

i think if you connect two resistance of the same value in series, and apply then apply 24 VDC, same half voltage will appear across each of them. e.g. 12 VDC across each by the formula
Vr=(R1)*24/(R1 + R2)

 

[daviddlc]

If your load is static (same current consumption all the time), then you apply Ohm's law.

If your load is dynamic (current changing) then you need to have a voltage regulator or something similar.

 

[ark5230]

The reply by jorgito is complete and appropriate solution. If additional information / requirements / constraints creep in, appropriate solutions will pop in. Else for such open questions many possibilities could be projected.

 

[oldeboots]

The solutions proposed using voltage dividers neglect that you may actually want to put some load on the resulting voltage. If you draw any current, the voltage divider will be incorrect. You may consider a series current limiting divider and a 12 volt Zener diode.