Samsung SCH-i730 Minty Boost

We bought a Samsung USB data cable from Verizon – the rep at the store said it was difficult to get. I thought we could charge our Verizon SCH-i730 with our MintyBoost USB charger. It’s wasn’t that simple.

For some reason, Samsung decided to add another plug in the middle of the cable – so you could plug in your charger! If you wanted to charge your phone while it was plugged into a USB port, you needed the charger. I thought the USB cable was supposed to obviate the need of a charger but Samsung must have a different idea.

I called Verizon tech support and they said that the Verizon stores didn’t even sell the cable. They didn’t tell me much.

After opening up the box in the middle of the cable, I traced the +5v from one end to the other. It was obvious that soldering a jumper would enable +5v to charge the phone.

Once the jumper cable was in, I reassembled the connector in the middle of the cable and plugged it into the phone. The phone icon changed to the charging icon meaning that it was being charged by the Minty Boost.

I looked on eBay, and found there were cables that didn’t need this mod for about 75% less than what we paid for this supposedly difficult to get (according to the Verizon rep at the store) cable.

At least it works.

To get your own MintyBoost charger, that works with iPods, Sony PSP, Nintendo DS/GameBoy Advance, Blackberry and a lot of other devices, go to Adafruit Industries. For a technical overview of the charger, go to ladyada.net.

MintyBoost USB Charger v1.1

Update: This post is about version 1.1 of the MintyBoost. ladyada has updated the kit to version 3.0.

In high school, I used to love building electronic things. That was so long ago, I was using vacuum tubes to make power supplies.

Once I made an audible tachometer for my car from a schematic in Popular Science. I even thought I wanted to be an EE and started at UC Berkeley in the School of Engineering. After a few quarters I realized that if I didn’t like learning engineering, I probably wouldn’t like doing engineering. (I think my friend Dan Kalman told me that)
Over the years, I still enjoyed making electronic things. Back in the mid 70’s, I had just moved to New York.

As a photo assistant, I used an answering service home answering machines weren’t in wide use.
By the late 70’s, I bought an answering machine and a pager. In those days, the only people who used pagers were doctors. I needed a way to know immediately that I had received a message on my answering machine.

I put a roller switch on one of the answering machine cassette solenoids that triggered a bunch of 555 timers. That dialed my pager’s number from a chopped up Radio Shack phone that had my pager’s numberprogrammed in one of the speed dial locations.

Years later, answering machines had their own call transfer feature.
When Make Magazine started publishing, I became a charter subscriber. The projects they were doing were all the kinds of things that I used to do. One of the projects I saw at the Make Blog, was kit called the MintyBoost, a USB charger designed by ladyada, that fits in an Altoids tin and runs on two AA batteries.

It basically takes the 3 volts from the batteries and boosts it to the 5 volts that USB devices use. Since we have a couple of iPods and cell phone that can be charged with the MintyBoost, I bought a kit.
You can update the v1.1 by adding a resistor.

It’s a great beginner’s kit and easy to assemble. You have to solder the components to the circuit board but you’ll learn basic soldering skills in the process.

The hardest part for me was finding the Altoids gum.

Once you’ve built the charger, you’ll have a something that is useful and may give you the satisfaction of making something yourself. That’s got to be worth something.