Power Supply for HeRos

This morning, I analyzed every components in order to get the voltage and the peak current. I looked at the pololu 3pi data-sheet how does the power supply work.

The pololu supplies 3 tensions:

  • Vbat : from the battery (3.5V-6V)
  • Vboost : Vbat with a boost module (9.25V) for motors and IR diodes
  • Vcc : Vboost with a linear regulator (5V) for logical electronics

Since every components are compatible with 3.3V or less, we can take Vbat without having a lack of voltage at any time. Only IR transmitters must not be supplied with more than 1.7V, we will use resistors in order to decrease the tension. The energy loss are not so big because the transmitters don’t work every time. We chose a buck switching regulator to get the 3.3V from the Vbat.


[migB] Wireless charging

In order to keep our migB smooth and beautiful (without ugly connectors), we plan to implement wireless charging. We are going to use the Qi standard, the most known nowadays. Basically we will connect a power regulator to a receptive coil (input) and to a lithium battery charger (output). The regulator and the charger may be in a single chip. Thus, the energy can transit properly from the coil to the battery.

Moreover, this is not really expensive. I think we can do it for less than 20€. I’m careful, the limit is high.

You can easily implement wireless charging on your smartphone. Many tutorials can by found on the web. You can also buy ready-to-use coils providing a regulated 5V voltage over a micro-USB port. Pretty easy.