Voltage divider producing unexpected voltage I'm trying to run a neopixel strip and an arduino from the same power supply using a voltage divider to get 5V to the strip.

Here are the values for my voltage divider:

R1 = 1500 Ω

R2 = 1000 Ω

Vin = 12 V

resulting in:

Vout = Vin*(R2/(R1+R2)) = 12*(1000/(1500+1000)) = 12*(1000/2500) = 12*0.4 = 4.8

When the divider is connected at its inputs but not at its outputs, I measure the expected 4.8V across R2. But as soon as I connect the neopixels, I only get about 1.6V.

Could anybody explain this || Suggest a possible solution?
Since you are connecting your pixel strip in parallel with R2, the
correct formula is

Vout = Vin × (R2∥Rp) / (R1 + (R2∥Rp))


Where Rp is the resistance of the pixel strip and

R2∥Rp = R2 × Rp / (R2 + Rp)


is the combination of R2 and Rp in parallel. From this you can see that
an output voltage of 1.6&nbsp;V is consistent with a strip resistance of
300&nbsp;Ω.

This is, however, somewhat oversimplified, as the I(V) characteristic of
the LED strip is probably non-linear, thus not really equivalent to a
resistor.