Hello,
I've designed a small modification to the great Minty Boost circuit to work with the dyno-hub of my bicycle (which outputs 2-6v DC). The goal is to power my cell phone while riding. The original MintyBoost circuit can be seen here: minty-boost-circuit.png. My modification is here: minty-buck-boost-circuit.png. The mod places a zener diode across the input to clamp the voltage there to 4.7V. Additionally two of the USB output lines need to be tied high to tell the phone to enter a charge state. I accomplish this by using two voltage dividers as can be seen in the modified circuit.
I'm fairly new to circuit design and am wondering if the voltage dividers will have side-effects that I don't know about. Should the voltage divider resistors be a bit larger to reduce the current to the data lines?
Thanks in advance!
Michael
I've designed a small modification to the great Minty Boost circuit to work with the dyno-hub of my bicycle (which outputs 2-6v DC). The goal is to power my cell phone while riding. The original MintyBoost circuit can be seen here: minty-boost-circuit.png. My modification is here: minty-buck-boost-circuit.png. The mod places a zener diode across the input to clamp the voltage there to 4.7V. Additionally two of the USB output lines need to be tied high to tell the phone to enter a charge state. I accomplish this by using two voltage dividers as can be seen in the modified circuit.
I'm fairly new to circuit design and am wondering if the voltage dividers will have side-effects that I don't know about. Should the voltage divider resistors be a bit larger to reduce the current to the data lines?
Thanks in advance!
Michael