NormanS8

Hey Matthew,Thanks for that. I wanted to buy a corded toothbrush next time, but it seems they are no longer available.But this section needs more details for those who don't know how to do such things, like me:Since the batteries had effectively died, I unsoldered them from the circuit board, and soldered on some wires of my own. (how to know what are the right size wires?) I connected the wires to an LM317 adjustable voltage regulator, so I could experiment to see what voltage worked to run the toothbrush. I had to add some power supply capacitors (how many, what size, any special way to connect them? if they are the right questions) to help keep a steady output voltage, and decided to try for 2.4 volts output. I computed the proper resistor values (how to do that?) to add to the regulat…

Hey Matthew,Thanks for that. I wanted to buy a corded toothbrush next time, but it seems they are no longer available.But this section needs more details for those who don't know how to do such things, like me:Since the batteries had effectively died, I unsoldered them from the circuit board, and soldered on some wires of my own. (how to know what are the right size wires?) I connected the wires to an LM317 adjustable voltage regulator, so I could experiment to see what voltage worked to run the toothbrush. I had to add some power supply capacitors (how many, what size, any special way to connect them? if they are the right questions) to help keep a steady output voltage, and decided to try for 2.4 volts output. I computed the proper resistor values (how to do that?) to add to the regulator, and got pretty close to 2.4 volts.best wishes

wow! that's great work. I wish I had learnt some of those skills. I just did it the cheater's way :-)

I appreciate your passion and thanks for shareing. I've converted my bike to electric, recycling laptop batteries, with the help of the techs at Substation33 in Kingston, Bisbane, Australia. They have a contract with the local government to make flooded road signs using recycled computer waste. They have built many e-bikes and an early one was justy like yours. I sent a link of your instructable to the tech there and he said:"Beautiful workmanship, but the batterypack is a real fire danger ☹ (Greg(who used to run the IT area here) built one of these format packs and it ended inflames), not enough insulation between modules."Hope you address that or it doesn't happen to you.best wishes