It’s pretty creative to use a 9v battery as an enclosure. ... and this method provides a built-in connector for a 9v power source. In this case the circuit is built around a LM386 audio amplifier.

Next thing to do is the design of a low-battery indicator circuit for use with the homemade rechargeable 6F22 9V battery tailored for pickups and other electronics that run on 9V battery. An LED ...

This circuit uses a 10F cap with a switching voltage regulator to increase the voltage from 2.3V to 9V. ... the type often powered by that form factor 9V battery and today, ...

A USB car charger, which will serve as the core of your DIY battery pack.Pretty much any model will work for this project — mine came from a gas station for a couple of bucks. A 9-volt battery ...

The battery pack and the output contacts are attached to the circuit board with decent wires in silicone insulation. Also, there are soft spacer sheets between the cells themselves, the circuit board, ...

Final Touches: Attach the 9V battery to the circuit, and your DIY USB charger is ready to use. You can now charge your USB devices on the go by simply connecting them to your new charger.

With some circuits, capacitors, a speaker, and a 9-volt battery, you can build a pocket-sized theremin to create spooky sci-fi sounds.

In a power outage, a 9 volt battery can give your phone enough juice to make a call or send a few texts. You may have seen this hack before, but it works especially well in this variation where ...

What you need: 3 crocodile-clip wires 9V battery LEDs Assorted resistors Asparagus THE candle. It is a simple technology, and a good one. The electronic version is also simple to make, and is a ...