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Mini Amp

I have a old pair of headphones and i was wondering is there any way i could power the speakers from the head phones and plug it into my guitar to use as a mini amp ?

Topic by jonathanbud    |  last reply


solar battery amp hours and panel which one ?

Hello, I am working on a project that is solar powered. I am not sure what kind of solar battery i should get and equivalent  solar panel to charge it.. and regulator --- The parameters are: The 'show' will take place every hour for eight hours during daylight hours.. Each hour every 10 mins the system will switch ON and power will be needed to operate 25 automatic car antennas that draw about 0.8amps for about 1 minute show time. So every hour I will be drawing 25*0.8*6 = 120  ? -- I am new to this so i figure my calculations are wrong as 120amps seems a lot -- the system will also be powering an Arduino board which will be controlling the overall timing and puppetering of the work ie some coil relays or transistors for lower power consumption. this project will be installed in Germany in the summer with average sunlight conditions .. From my reading up on the subject I understand that it is not good to drain a battery, ideally half drain is max...could someone please advise what values i need for battery and solar panel.. thanks in advance .. Cc

Topic by carloc    |  last reply


Nuclear powered throwies keep Boston on terror alert for sixth decade, seventh on horizon.

OK, so it's an attention-grabbing headline, but the potential is now there.Radio-isotope batteries (the same things that have kept the Voyager craft alive since the seventies) can hold a million times as much charge as a standard chemical bettery the same size.As radioactive isotopes decay, the charged particles they emit are trapped by semiconductors and turned into useful current.  Past versions of the battery have used solid semiconductors, which suffer damage from the radiation, so need to be large to survive as long as the isotope.  Now, a team from the University of Missouri has developed a liquid semiconductor that can survive the damage whilst having much less bulk, and have put together batteries the size of a coin.  They are working on much smaller versions, capable of powering micro- or nano-scale devices.Just imagine the possibilities...University of Missouri - Nuclear battery linksBBC Story

Topic by Kiteman    |  last reply


Throwie/Blinky using LED for Solarpower or using Radiowaves

Hello,I was wondering if its possible to make a "battery-less" throwie or blinky.I know there have been some solar throwies arround, but when looking through a message-board I found two circuits that use radiowaves or photovoltaik properties of a LED.The only difference is that the "bettery-less" throwie would have to collect power untill its dark, and then feed from it.Since I am not really into all the electronics yet, I do now know how well capacitors will keep their load, and if a aditional day/night switch detector will consume much power.The LED-drives-itself circuit: LED drives itself from Mikrocontroller.net(I've read in the forums that preparing the LED with sandpaper so its diffus will make it less angle dependant to charge?)The Radiowave-Blinker circuit: Radiowave blinkerfrom the german electroniwerkstatt-Forum (Click and look at end of toppic)A simple day-charge / night-operate circuit (such as a garden solar night light)[http://solar night LED https://www.instructables.com/id/EPYWPCC3M0EVYE00UZ/ CLICK]Has anyone build something like that?

Topic by schorhr    |  last reply


What is the right way to connect the cells of this battery pack, and tips on making a power bank? Answered

Greeting makers, I have a few questions about connecting Battery cells, and making a DIY Power Bank. And I'd like to hear your opinion on it. I have 12x Ni-Mh 1.2v 3000mAh AA betteries laying around. They are brand new and I thought of using them to make a Power Bank. Since most phones use 5v for charging I wanted to connect 4 cells in series giving me 5v and 3 of these packs in parallel for an end result of a single 5v 9000mAh Battery Pack. But when I started to connect them I realized that there are 2 ways it can be done, and I am not sure which is the right one. Is there any difference at all?  I will add a picture below, as it says more than thousand words. Furthermore I would like to ask for your opinion on how to proceed making a functional power bank. Just wiring the cells straight to an Usb port doesn't seem like a smart idea.  What would I need to make sure it is safe for the devices it charges? And how could I make the Power Bank rechargeable via Usb? Thanks in advance.

Question by icemaciop    |  last reply