3V Update for Flight Controler version 1.0 and 1.1

Reason for the modification

Some users noticed that the acceleration, gyroscope, and altitude sensor values varied a lot even with the flight controler at rest (http://forum.mikrokopter.de/topic-2268-1.html). This was due to a missing capacitor after the 3V regulator. By placing a 3.3 µF Tantal capacitator over the regulator from 3V to GND the problem is corrected.
This modification is not needed for flight controler v.1.2 (and later) as it has been integrated in the updated design.

Needed parts and position of the modification

All that is needed is a single 3.3 µF Tantal capacitator. Two possible sources are listed here, but most electronics shops should be able to supply one:



481696 - 62 (Conrad)

TANTAL 3,3/35V

TANTAL 3,3/16 (Reichelt)

TANTAL 3,3/16

Note that you MUST take care as these are polarised capacitators.

  • . http://www.aelum.de/mk/tantal.gif

The pins of the IC5 uA78L03 3V regulators


Changes to the flight controler

The capacitotor must be placed so that it connects to the 3V power regulator IC5 (LP 2950 ACZ3,0) out pin with its positive lead, and with ground with its negative lead.

  • . . http://www.aelum.de/mk/3,3V.gif http://www.aelum.de/mk/3,3V_2.gif

Actual conversion

Seen from the bottom of the flight controler the 3V pin and ground pin of the 3V regulator are marked red in this picture.

  • . http://gallery.mikrokopter.de/main.php/v/tech/3v_unten.jpg.html

  • . .
    Shorten the capacitator wires, connect the positive wire to the 3V pin, and the negative wire to the GND pin. With the capacitator more or less flat against the PCB it will not cause any problems with mounting the PCB.

  • http://gallery.mikrokopter.de/main.php/v/tech/fc-1_0-3V-tantal.jpg.html