• The plan
  • Use cases
    • Powering phone while navigating
    • Charging a powerbank on the way
    • Charging a powerbank via a solar panel?
• The specs
• Design
  • Power input
    • Active voltage doubling rectifier
    • DC/DC MPPT converter
    • DC/DC step up converter 5V USB
    • DC/DC step up converter 6V lamps
• Code
  • TODO
  • Improvements
    • ADC
• Interesting links
  • Git repository
  • Datasheets
  • Theory

The plan

Use cases

Powering phone while navigating

Charging a powerbank on the way

Charging a powerbank via a solar panel?

The specs

$V_{i{n}_{Max}}=?==20V_{pp}$

$V_{i{n}_{Min}}=5.5V?==5.5V_{pp}$

$I_{DCi{n}_{Max}}=0.66A^{[0]}$

$P_{i{n}_{Max}}=13.2W$

[0]: Limited by current sensor resistors

Design

Power flow:

Data flow:

Power input

Single phase AC or DC voltage from 0Hz to theoretically 100kHz.

Active voltage doubling rectifier

Can rectify actively with low rectification losses (

$R_{DSon,max}=18m\mathrm{\Omega }$) over MOSFETs or passively over high current schottky diodes.

• 1.1A input fuse
• 20VDC voltage clamping
• Additional input for DC voltages (solar)
• Input voltage pulse counter for speed/movement detection

Add switch for voltage doubler/full bridge rectification?
Add switch for capacitive voltage divider?

DC/DC MPPT converter

• Input/output voltage and input current measurement.
• Controlled via ESP32.
• Low loss DCDC converter via half bridge MOSFETs
• 10A single shot fuse for battery
• !BUCK_SD has to be high for the IC to work

DC/DC step up converter 5V USB

Device name ACT2802b

• controlled by a powerbank IC
• 2.2A USB output
• USB A
• USB C

USB C for charging?
ST USB C Charging IC Interesting path, but maybe not top priority as the power output is limitited from the dynamo so we won't get near USB C charging speeds.

USB C with PD is not really a viable option as we can not provide the needed power (even without we can do 5*2.2=11W)

DC/DC step up converter 6V lamps

• controlled by the ESP?
• "light me home" function, light stays on for 60(?)sec after stopping. Safety feature for waiting in traffic?
• Can be set to blinking/dimming while standing?

Code

void setup(){
    initAll();
}

void loop(){
    driveBuckConverter(findMaxPowerPoint());
}

idiot is coding

TODO

• Test if programming works
  • Test if serial print works
• Initialize all GPIO's
  • Check if GPIO's are working properly

L1 - L4 are not working. (wrong pins)

• Make BUCK converter
  • Open loop PWM (constant pwm)
  • Closed loop PWM
  • Closed loop PWM with flyback MOSFET
  • Maximum power point tracking
• Turn on and off front and backlight with buttons
  • Feedback over LED
• Turn on and off USB output with buttons
  • Feedback over LED
• LED for "battery is charging from dynamo"
• Dynamo power as output (serial or BT?)
• [ ]

Improvements

ADC

A lot of variance on the ADC measurements.

Interesting links

Git repository

Git

Datasheets

Theory

Ti document about buck converter calculations.
mppt

https://docs.gimp.org/2.10/en_GB/gimp-tool-foreground-select.html