Eternal Lantern with Dynamo: Features and Benefits

A flashlight is an indispensable thing. And if this is an eternal flashlight, then it simply has no price. It can come in handy at any moment: there is a power outage in the apartment, an unforeseen situation can happen on a trip, in the garage, at the dacha. Just imagine what will happen if the battery runs out at the most inopportune moment. But if the flashlight has a dynamo, then there is nothing to worry about. You will always be with the light.

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A mobile phone has long become an important attribute of a modern person.
It is very inconvenient if it suddenly discharges at the most inopportune moment - on the street or even far from civilization. However, you can insure yourself in this case, and the simplest option is a manual charger, with which you can recharge your phone (as well as a tablet or any other gadget) in any situation. Let's look at several similar devices in this post. We will consider products from Aliexpress, since in Russian online stores the range of such devices is small, and if they are sold, then at a noticeably higher price. It’s easy to order goods from Aliexpress; if you haven’t done this yet, you can find out more about this online store in one of the previous posts.

By the way, this post is regularly updated; we check links to products and try to select options that are the most affordable.

1) The simplest and cheapest manual charging

It looks like this. It's a simple box with a generator inside. If you turn the knob, a voltage of about 5 V appears at the output, which is exactly what is needed to charge a mobile phone. A minimum of frills - there is no built-in battery, only an LED indicating that there is voltage at the output. The price of such a device is low - about 150-200 rubles. including delivery. As they say, cheap and cheerful.

Can I use this simple generator to charge my phone? Yes, you can. But let's be honest - it's not very convenient. If you read the reviews, the device is quite flimsy and breaks easily. But its main drawback is that in practice a cheap generator produces a weak current, far from the 600 mA stated in the specifications. You will have to turn the handle for several minutes to charge the phone even a little. In general, you can buy a device only as a last resort.

2) Flashlights with phone charger with mechanical generator and radio

There are quite a lot of such flashlights on Aliexpress now, here are a few options.

A flashlight with a mechanical generator and a radio, there are adapters for charging your phone via a USB cable. Flashlight link.

Flashlight with FM and AM radio, solar panels and 2000 mAh lithium-ion battery. Charging cables included.

Instead of one device, you get several at once: a hand generator, a solar battery, a power bank, a radio and a flashlight. The built-in battery can be recharged in three ways - from a solar battery, a manual generator and an external source using a USB cable. If you turn the generator handle for a minute (making about 150 revolutions during this time), this will be enough for 10 minutes of flashlight operation, 20 minutes of radio operation, or recharge the phone for 10 minutes of conversation. The device is small and can be easily carried in your pocket. Probably, if you need a hand charger to carry with you, this is the best option to buy.

Another flashlight with a larger generator. It has even more functions - a mechanical generator, a solar battery, a built-in battery + the ability to add batteries. There is also a three-band radio, a flashlight and a separate LED “reading” lamp. You can charge phones and other devices via a USB cable. You can buy this item using this link.

3) Large flashlight with phone charger, generator and radio

If the previous flashlight easily fits in your pocket, then this is an option, rather, for a hike or outdoor recreation. Powerful flashlight plus optional LED bulb, AM and FM radio, solar panel, siren and charging port.

What is an eternal lantern?

The eternal lantern also has the name dynamo lantern. Many dynamo flashlights do not have batteries in their configuration, but they are not limited in terms of use, unless the light bulb, which is screwed into the mechanism itself, becomes unusable.

Now manufacturers use an LED lamp, which has the longest service life (about twelve years of continuous burning). Therefore, dynamic lights are conventionally called eternal.

Wood cutter with oak handle

A couple of weeks ago they sent me carbide caps for wood cutters. Very sharp, with a hole for an M6 bolt. I’ve been wanting to make a decent chisel for a long time. Of course, I have them, but I wanted them to be really beautiful, practical, reliable and powerful! I ruined the first eucalyptus handle, began to put it on and split the handle, and decided to make the second one from an oak table leg. Well, in general it’s ready, done. 14 mm rod from the shock absorber strut.

The first version of a eucalyptus handle. I screwed the feather drill to the shock absorber rod, and the cutter was screwed through a lead gasket, I was just afraid of splitting it when tightening.

The handle was sharpened with a cutter that will be installed in this handle

We increase the “tension”.

Scheme 5 and 6 - increase power at medium speed using a control capacitor.

Scheme 2 for comparison.

Scheme 5.

Circuits 2 and 5 are distinguished by capacitor C2, which is located between the dynamo and the rectifier. How this affected the power of the LEDs depending on the speed at various values ​​of C2 can be seen in this graph:

Although there is no noticeable difference at very low and very high speeds, at medium speeds we still get extra power. Unfortunately, this increase comes at a high price: C2 must be non-polarized and its value is very critical. Capacitor C2 at 220uF works great with a regular bottle dynamo, but to work with a hub dynamo its capacitance must reach a monstrous 1500uF. The required non-polarized capacitor is difficult to find, it is very large and expensive. Circuit 6 overcomes these difficulties by using two standard polarized capacitors. They provide double the capacitance and are suitable for the ultra-low equivalent series resistance capacitors used in multi-mode power supplies. Resistor R1 is not critical, it depends only on C2 and C3.

Scheme 6.

Charge your smartphone in the mountains without an outlet: Muscles!

For those who are accustomed to relying on their own strength to charge a smartphone in the mountains, and even on the plains (we are on a hike, without an outlet nearby), distant startupers have carefully built a lot of chargers, indeed, thousands of them.

One of the latest, with the significant name American Red Cross FRX3, contains “inside” not just a neon, but a radio, a flashlight, an external speaker, and a manual generator. According to the manufacturer, one minute of rotating the knob gives 15 minutes of playing music or working with a flashlight.

So, a few years ago the Roto Charger appeared. You get the energy for charging as if you were winding fishing line onto a reel. A minute of active work will turn into three minutes of conversation with a regular dialer.

In this device, and a lot of its other analogs, you will have to turn the handle for a very long time to charge the smartphone. However, to send coordinates to rescuers, such a charge may be quite enough. Therefore, charging your phone away from civilization is also an option.

There are options that are at least less labor-intensive but much more time-consuming. Thus, Filipino teenager Angelo Casimiro created sneakers that generate electricity when walking. The generator consists of two piezo disks in the insole. Two hours of playing basketball is enough for a 10-minute phone charge.

We increase the power by increasing the number of LEDs.

Scheme 7 - installation of several LEDs.

The dynamo is a more or less stable constant current source, so connecting two LEDs in series roughly doubles the total power output of the system. Why not connect three, four or even more LEDs in series? To obtain additional power, you need to install regulating capacitors from circuit 6.

Depending on the number of LEDs and the type of dynamo, the components used vary greatly:

To obtain these values, a Busch & Muller Dymotec6 bottle dynamo (8 magnetic poles) and a Shimano DH-3D71 hub dynamo (28 magnetic poles) were used. It is likely that different dynamos of the same type will operate similarly. Check to see if YOUR dynamo contains a reference diode designed to limit the output voltage when used with light bulbs. It needs to be removed.

Now let's look at the power curves. It's amazing that a 3-watt hub dynamo delivers over 10 watts of power to the LED string! Of course, this doesn’t come easy - as you receive more power, more effort is put into pedaling.

Please note: on curves with high power output, more effort is required, and at low speeds the headlight barely shines. For example, a system of six LEDs produces no light at all at a speed of 8 km/h. Therefore, such a scheme is not acceptable for many. Why not solve this problem by moving to another curve at low speed? Read on.

We buy on the Internet

A mobile phone has long become an important attribute of a modern person. It is very inconvenient if it suddenly discharges at the most inopportune moment - on the street or even far from civilization. However, you can insure yourself in this case, and the simplest option is a manual charger, with which you can recharge your phone (as well as a tablet or any other gadget) in any situation.

Let's look at several similar devices in this post. We will consider products from Aliexpress, since in Russian online stores the range of such devices is small, and if they are sold, then at a noticeably higher price. It’s easy to order goods from Aliexpress; if you haven’t done this yet, you can find out more about this online store in one of the previous posts.

The functionality of this device for the hunter

A rechargeable dynamo flashlight, due to the fact that it does not require batteries to function, is in demand by hunters, fishermen and tourists. Real dynamo lights are quite expensive, but they serve the purpose - they really last a long time and provide a decent level of quality.

The Eternal Flashlight is indispensable for true trackers. There is no need to save money when choosing a flashlight.

Advantages of a Faraday flashlight:

1. Compact, light. A quality dynamo light is waterproof. Such lamps are very light in weight, they are compact, and have excellent protection against damage and shock.
2. Multifunctionality. Using a flashlight you can charge phones and cameras. Many models are multifunctional because they have built-in compasses and receivers.
3. A large assortment. Choosing a timeless flashlight from a huge variety is very difficult. There are many models, they differ in designs. There are small models, they reach only 5 cm in length. Faraday flashlights come in different power, functionality and designs. Everyone can choose according to their taste, capabilities and needs.