I have a 12VAC dynamo I am planning to put on my bike and I want to know how to transfer the electricity generated into a Micro USB cable or USB port. There are devices out there costing upwards of $100 to do this but I want to know if there is a cheaper way for me to construct something like this.


The design I had and device I had originally designed worked, I was just using a faulty USB cable.


closed as too broad by pipe, winny, Chris Stratton, Leon Heller, RoyC Mar 28 at 8:00

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ easily found on the bay of fleas - have you looked? \$\endgroup\$ – Solar Mike Mar 27 at 15:05
  • \$\begingroup\$ 1st specify Isc and Voc for short and open circuit in your desired speed range. Then max load power \$\endgroup\$ – Sunnyskyguy EE75 Mar 27 at 15:06
  • \$\begingroup\$ what voltage are you trying to produce? \$\endgroup\$ – jsotola Mar 27 at 20:31

Since you are starting with AC the first thing is to rectify it into DC. A bridge rectifier is good for that. Now that you have DC (albeit lumpy), you will want to add some bulk capacitance (to remove the lumps). Then finally use a DC-DC converter to convert the 17Vdc into 5vdc. WAIT, WHAT? 17Vdc?

The answer is purposely kept high level and general to encourage learning and discovery on your own. Also how 12Vac becomes 17Vdc is an exercise for the student.


Not the answer you're looking for? Browse other questions tagged or ask your own question.