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Wind turbines function using the same fundamental principles as hand-powered generators.
© iStockphoto.com/EdeWolfWe often take for granted the convenience of our modern electrical grid, assuming we'll always have access to electricity when we need it. However, there are many instances when power isn’t readily available, and places without outlets to charge your devices. For example, if you venture into the wilderness or face an emergency, you might find yourself without power. After severe storms, it can take days or even weeks for utilities to restore power. And, of course, there's always the possibility of a zombie apocalypse leaving society in ruins. The batteries for your devices will only last so long.
Yet, there’s one way to generate electricity that never runs out and is portable: the hand-powered generator. It’s the ultimate travel gadget that can keep all your other devices running — from your phone and MP3 player to an emergency radio. This article explains how hand-powered generators work and what they’re capable of.
How Hand-powered Generators Work
The operation of hand-powered generators is straightforward. They function like other generators, but instead of relying on steam, burning coal, or flowing water, your arm supplies the initial energy. Essentially, a generator is an electric motor running in reverse. Both devices operate on the principles of magnetism discovered by physicist Michael Faraday.
In 1831, Faraday discovered that moving a conductive wire through a magnetic field created an electric current within the wire. By rotating a coil of wire around a magnet, he realized that a steady current could be generated. This process allowed him to convert mechanical energy into electrical energy. This concept powers generators running on gasoline, diesel, and the huge turbines in modern power plants, where water or steam turns the coils.
This principle can even be applied to a compact generator small enough to fit into a travel device you can carry in your pocket. Instead of relying on gasoline, steam, or flowing water, you turn the crank on the generator yourself. As you rotate the crank, the coils move around the magnet and produce electricity.
Some basic hand-powered generators lack voltage regulators, which can be problematic when used with delicate equipment. For instance, if you connect one to a light bulb and crank it too fast, you could burn out the filament. However, most modern hand-powered generators designed for specific gadgets do include voltage regulation, ensuring the device works correctly with the generator.
Next, we'll guide you on how to use a hand-powered generator.
Since a generator functions as an electric motor in reverse, creating your own hand-powered generator is relatively easy. All you need is a cordless electric drill and some basic electrical wiring knowledge. Remove the battery pack from the drill, then connect the wires in the battery compartment to the device you wish to power (rechargeable batteries are ideal). Attach a large handle to the drill's chuck, press the trigger as if activating the drill, and turn the handle. You may need to experiment with a voltmeter, adjusting the direction you turn the handle, as well as the torque and direction settings on the drill, but once you get it figured out, you can charge your batteries by turning the drill by hand for several minutes.
Operating Hand-powered Generators
Using hand-powered generators is straightforward. Some travel gadgets even come with built-in generators. For example, gadgets such as radios and lights with built-in hand-powered generators are popular on camping trips. These devices typically run on regular batteries, but if you're left with dead batteries while stranded, a hand crank allows you to power them enough to get a weather report or use the light. You won’t need to connect the generator to anything externally because everything works internally within the device.
Other hand-powered generators are designed to work with specific devices, such as particular cell phone models. These generators are small units with a hand crank and a special connector that links to the phone. Simply turn the crank to start charging the phone's battery. Although the voltage generated will fluctuate depending on the speed of cranking, built-in voltage regulators ensure a steady flow of electricity. The longer you crank, the more power you generate. A few minutes of cranking is typically enough to make a quick emergency call from your phone.
Some hand-powered generators are designed with greater flexibility. Rather than being dedicated to a single device, they come equipped with electric leads, a cigarette lighter-type socket, or a standard electrical outlet. This allows you to connect any compatible device to the generator for power. However, not every device is suitable for use with a hand-powered generator — only those that match the generator's current and voltage output will function. Typically, these generators produce direct current (DC) power, but some feature internal inverters to convert it into alternating current (AC). Most hand generators can produce up to 6 volts, though certain models have gears that increase the cranking speed to generate higher voltages.
If you’re wondering whether hand-powered generators are a recent invention, they’ve been around since at least the 1960s. Military units used specially designed hand generators that could fold into a backpack. With a soldier turning the crank, these generators powered electronic devices while stationed in the field, far from any available power grid.
If you’re curious about trying out a hand-powered generator, you can find them at many outdoor equipment retailers. They’re also available from educational supply stores. Many of these generators come with transparent casings, allowing you to watch the coils and magnets at work as the generator operates.
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