# Voltage divider resistor power disipation [duplicate]

I am trying to create a power supply circuit for the ESP8266, using a voltage divider and a cellphone charger rated at 5V, 1A as power supply.

I have resistors connected like this:

The resistors are rated at 1 - 6 W. Using an online calculator for power dissipation i get 900W per resistor for the ESP8266 max current of 300mA. I am using 3 10K resistors with two in series for the 20K part.

I guess this is the correct reasoning.

Could someone explain if I'm doing something wrong and if this will work?

## marked as duplicate by PeterJ, Community♦Feb 7 '16 at 12:37

• Look at Peter Bennett's answer here : electronics.stackexchange.com/questions/111646/… – Marla Feb 6 '16 at 17:12
• A resistor voltage divider is not suitable for use as a power supply. Never. Not ever. – brhans Feb 6 '16 at 17:12
• Yes but I'm asking because i don't have a regulator with me. What will happen in this circuit? Will the resistors melt? – JJ_Jason Feb 6 '16 at 17:17
• The output voltage of the divider will vary depending on the current drawn from the output. Your ESP8266 will effectively be a variable resistor in parallel with the 20 K resistor. I believe the ESP8266 can draw 250 mA or so when transmitting - that would theoreticaly produce 2500 volts across the 10K resistor!! – Peter Bennett Feb 6 '16 at 17:22
• We should have a giant "no, bad dog" sign for any voltage divider power supply question. – Passerby Feb 6 '16 at 17:55