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I have an input voltage of 12V from my power supply and i need 6V to feed into the ESP8622. I was giving it all the 12V but the wifi module becomes increasingly hot with time and so i decided to have a limited voltage feed into it.

Am not getting it to fire up however. It still stays blank.

I tested providing the 6V from the power supply and got positive results.

My resistors are both 100 ohms and when i probe the interconnection rail of the resistors on the breadboard, i can see that 6V is there. But when i feed the link into the ESP8266, it doesn't light up. It only does when the 6V are coming from the power supply.

Here is a pic of my circuit enter image description here

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  • \$\begingroup\$ What do you measure at the divider when the ESP8266 is connected? Surprise - It is likely to be much less than 6V. \$\endgroup\$ Nov 28, 2018 at 20:37
  • \$\begingroup\$ When i measure, i get 5.9V...still within the range of my desired voltage from the divider. \$\endgroup\$ Nov 28, 2018 at 20:39
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    \$\begingroup\$ That's probably because you are not looking at the dynamic current consumption spikes that are causing the problem. \$\endgroup\$ Nov 28, 2018 at 20:52
  • \$\begingroup\$ You shouldn't feed the ESP8266 with 6V The nominal voltage is 3.3V, and 3.6 is max. \$\endgroup\$ Nov 29, 2018 at 0:50
  • \$\begingroup\$ And again, attention to details: is it ESP8622, or ESP8266? \$\endgroup\$ Nov 29, 2018 at 0:54

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Practically speaking, you cannot create a lower voltage power rail from a higher voltage power rail using a simple voltage divider. Not unless the current draw of the lower power rail is very small. It's an impedance issue. If you consider the device you are trying to power as a small value resistor relative to the resistors in your divider this will make sense, as it would be in parallel with the lower resistor of your divider essentially making it a much lower value... and no, don't go down the path of trying to make the resistor values in your divider smaller, you're trying to solve the problem the wrong way.

This is typically done using a voltage regulator to convert your 12V down to 6V. Voltage regulators are made to do the voltage conversion and have low output impedance (i.e. they can source more current without issue). Find a voltage regulator that will take your 12V and give you 6V and that is rated to supply whatever current you need.

Edit: Since what you really need is 3.3V, and since you potentially need a couple hundred mA of current, look at something like this: https://www.digikey.com/product-detail/en/cui-inc/VXO7803-500/102-4248-ND/7350287. All you need to do is add a 10uF input capacitor and a 22uF output capacitor as explained in its datasheet. That's about as simple as you are going to get. And if you hooked up 12V to your ESP8622 already, you probably damaged it, so you will most likely want to get a new one of those too.

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  • \$\begingroup\$ well i was trying to avoid the use of a voltage regulator thinking i could do away with a simple voltage divider circuitry. But i think the ESP has a voltage regulator too inbuilt and perhaps its the one causing the voltage to go way too low. Coz when i measured the voltage with the ESP connected, it was around 1.6V \$\endgroup\$ Nov 28, 2018 at 20:46
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    \$\begingroup\$ The ESP8266 datasheet indicates it can draw in excess of 200mA in certain modes. Also, it is made to be powered from 3.3V, not 6V as I look at it. If you hooked up 12V, you probably damaged your device. Get a new module, and then if your power source is 12V, get a voltage regulator that will convert that to 3.3V and can provide at least 250mA just to give yourself some margin. \$\endgroup\$
    – user205769
    Nov 28, 2018 at 20:50

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