Opencoil/electronics

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Revision as of 20:18, 28 August 2022 by Scootyandspeedy (talk | contribs) (Created page with "# opencoil-paracity: electronics ![picture](https://git.vvvvvvaria.org/then/opencoil-paracity/raw/branch/master/electronics/esp-wireless-charging-pcb/pcb-ass.jpg) *Assembled pcb* ## Bill of Materials * PCB: Send the gerbers from this repo to your fab of choice. * ESP12F: Widely available. * AM1117 3.3v Regulator: Widely available. * QI compatible wireless charging coil delivering 5v and > [500 mA](https://docs.ai-thinker.com/_media/esp8266/docs/esp-12f_product_spe...")
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  1. opencoil-paracity: electronics


![picture](pcb-ass.jpg)

  • Assembled pcb*
    1. Bill of Materials
    • NOTE**: Be aware that these 'adaptor coils' could contain additional circuitry that condition the output for use with specific mobile phones (the pearl.de ones do). Below is a guide to modify the 'pearl' coils to deliver maximum voltage (5v)constantly, instead of switching to low power, 2.5v output when not enough/too much current is drawn.


    1. Modding 'adaptor coils'

If you have soldered all components together and your ESP12f won't boot, you might have to modify your charging coil+circuit a bit. To make sure it's the coil, measure the output of the coil's electronics on the + and - (GND) terminals. If your multimeter reads ~2.5 volts you need to modify the circuit. (Disclaimer: the exact details on how this circuit works are yet unclear, comparing to a working coil revealed several differences in the electronics, matching them up made the non working coil output the needed 5v).

      1. Step 1

You need to desolder two IC's/ chips following the (visual) guide below. The electronics and coil are sandwiched between two layers of foil. To peel the foil away look for an opening near the lightning connector.

![picture](001-coil.jpg)

![picture](002-peel.jpg)

You are then left over with the bare coil and flexible pcb. Here I already desoldered the lightning connector flex pcb.

![picture](003-bare-coil.jpg)


Remove the following chips indicated by the following silkscreen printing:

  • Q3 (chip markings: p7)
  • Q4 (chip markings: wsc7)

![picture](004-q3.jpg) ![picture](005-q4.jpg)

A hot air reworking station + tweezers will make quick work of that (settings: 1 second on 320deg, moderate airflow). Without hot-air you could try a soldering iron or fine wire-cutters to simply cut away the chips. The flexible PCB is very fragile though.

![picture](006-hotair.jpg)

Step 1 completed!

![picture](007-hotair-done.jpg)

      1. Step 2

With both chips removed, you have to bridge two of the three (now) bare connections of the transistor Q4. I could not find a datasheet on this transistor so please refer to the photo's to see which pins.

![picture](008-bridge.jpg)

Done!

![picture](009-done.jpg)