Two Maumee Valley County Day School students sent a sketch and problem to our President’s attention, asking if we could assist with a belt phone charger design. He gave the challenge to two young engineers (soon to be registered) and the following is the solution Arin Rightinowar sent back to the students two days later. Obviously, this hit his engineering button!
My name is Arin Rightnowar. I read your email and I think you are off to a great start with your project. I have reviewed your design and I do have a few suggestions about the 9V battery.
The problem with using a 9V battery is that it cannot supply the proper voltage to the phone charger that commonly runs off of 12V in an automobile. In the electrical world, if you don’t have the proper voltage for something, you have to have more current to supply to compensate for the deficit in voltage.
For example, say you have a squirt gun and you are trying to knock over a target (which is what you are trying to power with electricity) some distance way and you are not able to get any closer to it. Voltage is representative of how much pressure your squirt gun has from you pumping it up and the current is the amount of water in the water tank. To knock over the target, you need a balance of both pressure and enough water to knock the target down. If you pump up the squirt gun as much as you can and there is little to no water in the tank, it won’t be enough to knock the target down. The opposite is true if you have plenty of water and not enough pressure you won’t be able to get the water to reach the target to knock it down.
If you look at the drawings I have attached (see attached .PDF file – shown here) I used what you gave me and came up with a design very similar to yours but using 8 AA batteries instead. The 8 AA batteries will provide the charger with 12V and if my calculations are correct around 6 hours of charge to your phone (this may be different as I used a car charger that can charge 2 iPhones at once so it needed more current); Yours may last longer depending on how much current it needs. In order to achieve 12V from 1.5V AA batteries I just divided 12V by 1.5V to give me the correct number of batteries. However, if you follow my wiring diagram on the second page, you can see how you must wire the batteries together in order to reach 12V.
Please feel free to email me back if you have any questions and thank you for taking the time to write us.”
We’re proud to be part of the vibrant Sylvania, Ohio community and active contributors to the Toledo / Northwest Ohio region — often providing in-kind services, volunteer / financial support and leadership skills.
The recently completed Jadel Leadership Center for the Erie Shores Council of the Boy Scouts of America is another great example of our involvement. The new building at the entrance of Camp Miakonda (which was established in 1917 and is one of the nation’s oldest Boy Scout Camps) houses offices, training/meeting space, a museum, the Scout Shop and serves as a welcoming place to all on the wooded grounds that are essentially an outdoor program area for more than 6,000 area Boy Scouts. JDRM Engineering provided all electrical and mechanical engineering services as an in-kind donation.