I recently bought a bike to ride to work, and in general, to ride and enjoy cycling. For safety, I turn on the front and rear lights so that the participants traffic I got noticed better. My LED lights run on two AA batteries. And the charge is enough for only 4 hours of driving. Actually, this prompted me to think about purchasing a bicycle generator that could power all the lights.
I didn't find anything in the stores. All flashlights are battery powered. Then I decided to make a generator for the bike myself, from what comes to hand, so to speak ...
And then I remembered that I once made a generator from a stepper motor. Decided to repeat the idea. But where to get a stepper motor? They are in almost all office equipment. I went into the pantry and found an old printer there. Naturally, it had a couple of stepper motors. I took one, I don't need more.
What else is needed for the generator?
You will need a few things if you want to build a bike generator. Here's what they are:- - Stepper motor from a printer or other equipment.
- - 8 pieces of diodes, any, for a current of 0.5 -
- - Voltage regulator LM317 -
- - Radiator for LM317 -
- - Bread board -
- - Switch -
- - housing for regulator -
- - Wires.
- - Wing mount.
- - Wheel from the machine.
Regulator circuit with a rectifier
We need to assemble a voltage regulator so that it not only rectifies the current from the stepper motor, but also regulates the output voltage, thereby protecting the LEDs from power surges while driving. The controller circuit is simple. Diode rectifier bridge and voltage regulator on the LM317 chip.
I assembled everything on a breadboard with holes. I just inserted the parts, bent the contacts in the soldering direction and soldered everything. I soldered the wires and now my regulator-rectifier is ready.
The toggle switch can turn off the generator.
Generator Assembly
We assemble the fastening of the stepper motor to the wheel. The principle is simple: the stepper motor turns the wheel, the motor generates electricity.I thought for a long time how to implement the mount both simpler and more reliable. Here's what I came up with:
I took the mount from the wing (anther, mudguard). I screwed an aluminum corner to it with screws, cutting it a little. And already attached a stepper motor to the corner. Everything - the design is tested, it works fine. Of course, it is desirable that she spring the engine to the wheel, but in principle, it is quite normal anyway.
Oh yes. A wheel from a typewriter with a rubber tire is put on a stepper motor. Electrical tape is wound around the motor shaft so that the wheel is tightly pulled onto the shaft. Nothing better came to mind.
Regulator mount
I also thought for a long time where to place the regulator body, where to attach it, because it must be in the vicinity of the stepper motor, otherwise you will have to pull 4 wires from the stepper motor.Finally, I came up with and decided to mount the regulator on the racks on the same bar where the stepper motor is mounted.
I cut a rectangle out of thin aluminum foliage, and screwed it with long bolts through racks 1 cm long. Well, I attached a regulator to the rectangle.
Checking the operation of the generator
The stepper motor I got was 24 volts. And at normal bike speed, it put out over 30 volts. The regulator at the output gave out 3.1 volts. Which is quite normal. If this voltage does not suit you, adjust it with 150 and 220 ohm resistors. In general, you can solder a variable resistor and adjust the voltage as you like.I connected the wires from the regulator to front lamp. Connected in parallel with the batteries. As a result, when the bike is standing, the lamp shines from the batteries. And when the bike rides, the lamp shines from the generator, and the elements are charged a little. Ideally, of course, you need to use batteries, but AA batteries with a voltage of 1.2 volts, the flashlight will burn dimly. And in principle, the batteries can be thrown out altogether, and the headlight will only burn in motion. In general, whoever wants.
There is a special device that can generate power supply. Such a device is a bicycle generator. The generated electricity is absolutely free. The development process occurs by scrolling the pedals. According to the varieties of generators of bicycle origin, there are 4 types:
- Bottle.
- Sleeve.
- Contactless.
- Carriage.
Quite closely and almost inextricably linked is the frequency of pedaling with the issuance of current strength, as well as voltage. This reproduction is inherent in all varieties of generators. Only alternating current is issued by a bicycle generator. In order for the current to be constant, it is necessary to install a rectifier bridge. It consists of specialized lamps of diode origin. Or you can install a two-half-cycle rectifier. You can buy a generator for a bicycle in special stores, as well as in car markets.
Bicycle bottle generator
This type of generator is called bus. By type, it is a minor value generator. The bicycle bottle generator consists of a body that is completely insulated. Outside, it has a special roller that is designed to rotate. It is tightly attached to the body, that is, to the plug. Also, the filling of this generator consists of a conventional copper winding and a magnet. The movement of the field of magnetic origin occurs due to the contact of the roller with the tire of the bicycle wheel. Based on this, there is a transfer of energy from the wheel to the mechanics.
The faster the wheel spins, the faster the roller on the generator spins. The maximum polarity is achieved in the generator itself, the voltage is reproduced.
The positive side of this type of generator is:
- Small price compared to other types.
- Ease of installation on the bike.
- The device can be easily turned off or on by moving away from the bike.
As for the shortcomings, they are not so significant:
- Tires wear out over time.
- It takes time to set the incline level.
- The appearance of sound due to friction against the tire, especially at high speeds.
- Slight misalignment of the wheel due to the weight of the alternator, which ranges from 200-250 grams. This is due to its fastening on one side.
- If the weather is rainy, then the generator does not work at full capacity. Friction on the wheel is defective due to slip.
But given these disadvantages and advantages, in general, this species generator is very efficient.
Bicycle contactless generator
Electricity is generated by the operation of the bottle generator. The carriage also produces current. In another way, this type of bicycle generator is called a hub dynamo. The name comes from the fact that no contact between the generator and the wheel is observed. The current appears as a result of close contact of the rim to the generator. Because of this, a magnetized field of the wheel rim is formed.
The lighting diode is directly installed in the device. The voltage goes directly, without any additional stabilization devices. Positive sides this machine is:
- No wheel friction factors.
- Compact and light weight, up to 70 grams.
- There are no connection cables.
The headlight, which is located in front, is mounted on a fork. The taillight is at the back. Based on this, these flashlights are independent in themselves. They burn not due to batteries, but due to the spinning of the wheel in the field of magnetism. The quality of the lighting output is at a sufficient level. In slow motion on a bicycle, the light bulbs are supposed to go out, but they don't. This does not happen due to the fact that a special capacitor is installed. In fact, it can be called a battery that gains energy while riding a bicycle.
Conclusion
Using a bicycle generator is beneficial. First, absolutely free electricity generation. Secondly, convenient and comfortable lighting of the road in the dark. The 12 volt DC bike generator is convenient to use and easy to install. It can also be assembled almost quickly. When transporting does not take up much space. A bicycle generator does no harm.
A bicycle generator is a device that allows you to get electricity by pedaling and transfer it to bicycle lighting or third-party electrical appliances. By design, bicycle generators are divided into several types: sleeve, bottle, carriage and non-contact.
The output current and voltage are inextricably linked with the frequency of pedaling - the speed of movement. The pattern is valid for all types of generators. The bicycle generator produces alternating current, which is stabilized into direct current using a rectifier bridge. Its role can be played by soldered diode lamps or special devices, for example, a full-wave rectifier.
Hub dynamo as electric motor
A hub dynamo, or a hub generator, is the usual one with a built-in magnetic mechanism. During rotation, eddy currents are formed, at the outlet of the sleeve, mechanical energy is converted into a current with a given force, voltage and power. On bicycle dynamos, the voltage reaches 6V, and the power is 1.8-2W.
The invention is patented by the English company Sturmey Archer. Today, production is actively supported by other manufacturing companies - Shimano and Schmidt.
Design features of the generator sleeve:
- fixed anchor (winding) on the axis;
- a ring magnet fixed and rotating together with the sleeve;
- terminals and double wires;
- high mass.
Shimano AlfineDH-S701 speaker
The bushing source of electricity does not use the bicycle frame as a ground and, together with the lamps, is isolated from it. In a full-wave rectifier, the AC (output) and DC (to headlight) circuits are completely separated from each other.
Hub dynamos are heavy, though the lighter rare earth magnets and aluminum shell have allowed for a slight weight reduction. In operation, the device has a low resistance to unwinding, and with an increase in the angular velocity, the frequency of the current increases. This effect smooths out the voltage gain and allows the generator to operate in wide ranges speeds.
The headlights that the bush generator is equipped with have a built-in current stabilizer. When connecting another headlight, a separate rectifier is installed in the circuit so as not to burn the electrical appliance. The brightness of the headlight depends on its requirements for the power source and, in fact, the output voltage of the bushing. The greater the discrepancy to the smaller side (the headlight is more powerful), the light will be dimmer. In the opposite situation, the light source will not work.
Bottle bike generator: features, pros and cons
Let's get acquainted with another source of energy - a bottle, or "tire" converter.
Bottle generator - a closed case with a rotating rubber roller on the outside, mounted on the front fork. In the case there is a directly converting device - a winding and magnets. The movement of the magnetic field is achieved by engaging the roller with the tire and directly transferring mechanical energy to it from the wheel. The higher the speed of movement, the stronger the polarity inside the generator and the greater the output voltage.
"Bottle" is afraid of bike falls
Advantages of bottles:
- the ability to turn off as unnecessary - just move the roller to the side;
- easy to install on any type of bike;
- inexpensive compared to bush generators.
Weaknesses include:
- weight bias: weight is about 250 g, a “bottle” is attached on one side;
- low efficiency in wet weather - the roller slips over the tire;
- noise, high friction at speeds;
- tire sidewall wear;
- long time to adjust tilt and position.
Separately, it is worth mentioning the carriage bicycle generator. Its body is fixed in the area of the pedal assembly - the carriage, under the lower stays. The rotation of the magnetic device is given by a roller that is engaged with the rear wheel of the bike. The fixation of the roller on the tire is provided by a clamping spring.
Contactless Bicycle Generator
Bottle and carriage generators produce electricity by contact with a moving wheel. The hub dynamo is a built-in element of the wheel. The contactless generator does not touch the wheel in any way, does not create friction forces and resistance to rotation. Eddy currents are formed due to the proximity of the plane of rotation of the magnetized rim and a strong magnet.
The headlights are built right into the device, the electricity is transmitted directly through the rectifier bridge. The undeniable advantages of this generator include:
- lack of cables;
- there is no friction force and resistance from the device;
- low weight of the structure - no more than 60 g.
Contactless energy sources can be safely used on road bikes for long distance travel
Devices are mounted in pairs: on the fork - the front headlight, on the pen - the rear reflector. In fact, these are independent flashlights, only they do not work on batteries, but through the rotation of the wheels in a magnetic field. The luminosity of the lamps is at the level or exceeds that of rechargeable lighting devices.
When the wheel slows down, the intensity of the eddy currents decreases, the bulbs should dim, and when the wheel stops, they should go out completely. To ensure uniform light and the ability to use the light even in the parking lot, the design includes a capacitor (“battery” for generating electricity), which is filled when the bike is moving.
How to make a generator with your own hands
And now let's try to make a generator for a bicycle on our own. As a basis, we will use a stepper motor. To power the lighting fixtures, you need an engine with the following characteristics:
- rated current - 2.4 A;
- resistance - 1.2 Ohm;
- output voltage - 2.88 V.
The dynamo should be installed near the rear wheel hub. To transfer rotation from the wheel to the handwheel (rubberized wheel) of the motor, a transmission ring is required. To create it, you need a flexible plastic tape. Manufacturing:
- Twist the ribbons into a ring, welding the ends.
- Cut mounting slots on the side for each wheel spoke. The depth of the slots is ¼ of the thickness of the ring.
- Put the ring on the knitting needles, fill the slots with glue-sealant inside at each needle.
When the ring is ready, a stepper motor is screwed onto the free seats to the feathers, and the flywheel is installed on top of the ring. If there are no free places for the engine, an additional plate with holes will need to be welded onto the frame.
The general scheme for creating a generator with your own hands: generator - assembly of an electrical circuit (bridges, resistors, capacitors) - connection - installation of headlights.
To assemble the electrical unit for the headlights, you will need:
- 1N4004 LEDs - 8 pcs (converter bridge);
- stabilizer LM317T;
- ceramic capacitor with a capacity of 1 μF;
- 240 Ohm and 820 Ohm resistors for the stabilizer;
- a 1W diode and a 110 Ohm resistor (0.25 W) to it;
- wires;
- plastic box where everything will be.
We assemble the components taking into account the following scheme:
Another version of this scheme:
Do-it-yourself electrical circuit
Assembly sequence:
- Solder 1N4004 diodes into parallel bridges.
- Solder a capacitor between the "positive" and "negative" ends of the circuit.
- Install resistors and voltage stabilizer.
- Solder an LED (1W) and a resistor to the headlight circuit.
- Through the wires, connect the headlight with capacitors, and then the electrical circuit with the generator on rear wheel.
- To turn off the lamp even while cycling, in the gap between the capacitors and install a switch that will close and open the circuit.
Homemade electric generator on the rear wheel of a bicycle
The body with the electrical circuit is fixed on the bicycle frame, we fix the wires with clamps.
On last step the operation of the system is checked: the wheel must pass freely along the wheel and move synchronously with it. With a properly assembled electrical circuit of capacitors, resistors and rectifier bridges, the headlight will turn on. True, at low wheel speeds, its light will flicker.
Conclusion
An electric generator will allow you to get additional benefits from pedaling - completely "free" to receive energy to light your two-wheeled vehicle when driving on a dark highway or rough terrain. Small and useful, this device is virtually maintenance-free and quite easy to assemble by yourself.
Hello dear colleagues! I bring to your attention an environmentally friendly source of electricity.
By the nature of my work, I have repeatedly had to solve the problems of power supply for remote objects. However, the applied methods are not acceptable to me for financial reasons. What remains is experience.
When planning the backup of the electrical supply of my “object”, I proceeded from the technical and financial possibilities available to me: when the electricity in one feeder runs out, I switch to another (ATS), the entire external network will be covered - there is a gasoline generator, the fuel will run out (well, or to save it) - solar panels. As a reserve - 6 pieces of assorted batteries from cars ("passport" capacity from 44 to 115 Ah). Their capacity, of course, is no longer the same as in their youth, but for small loads they will do quite well (I also use it as a starting battery for resuscitation of frozen cars).
The minimum total power of consumers in winter is 100 W (boiler automation, circulation pump and 2-3 LED lamps). In the event of an acute shortage of gasoline, I will not provide so much solar grace alone (short winter day + snow). Well, or it is necessary to increase the area of solar panels (expensive pleasure).
The idea of creating a simple backup source of electricity “from what is at hand” has been around for a long time. To invest a lot of money by my standards in something that may never be needed, I think it is not reasonable.
So there are: used car batteries in stock, a used 80A generator (from dozens of VAZs, changed from time to time for a more powerful one), my son's bicycle. And legs. And, of course, hands. 
The son made a stand for the rear wheel from pieces of plywood. The rear wheel axle nuts were replaced with "pegs" (foot supports, used when performing cycling tricks). With the help of pieces of a metal profile and an M8 stud, a generator was fixed on the rear wheel. Plugged in the battery and started charging it. 
Aha! Schaz! Strength is not enough. I began to understand and count. The relay-regulator holds (trying) 14.5 V, the battery charging current is 4-5A. Total more than 70 watts. Taking into account the losses of the pedal-chain-tire-pulley, probably the same amount is needed. Vicki reports that this is unrealistic - I have never been an athlete.
You need to reduce the power somehow. The charging current depends on the design (size) of the battery, you can’t change anything here - we use what we have. The tension remains. I remember that in motorcycles there were 6 volts. You can remove 6 volts from a 12-volt generator using a suitable voltage relay instead of a regular car one. And charge a 12-volt battery in two runs, “dividing” it in half. This will halve the force on the pedals by doubling the time of their rotation.
In the battery I used, the jumper between the third and fourth banks is located just under the cork (if you remember, the jumpers were outside before, now I have only seen them on trucks). I found a 100-mm self-tapping screw, soiled in silicone (I cleaned the nose of the gun), Silicone - protection of the iron self-tapping screw from acid, or rather, on the contrary - electrolyte from foreign pieces of iron. Slowly, carefully, with effort, I twisted it into a jumper (the main thing here is not to overdo it and not scroll through - you can close the plates in this jar) and got the third contact. It must be remembered that it is a plus if it works in tandem with a regular "minus" and minus, if in a native "plus". 
I remade the standard relay-regulator into a simple brush assembly (bit off the relay legs, soldered the wires), installed PP1 from Izhak and the process started! The motorcycle relay kept the voltage no higher than 7.5 V (average approx. 7 V), the average charge current was approx. 4 A. The effort on the pedals is normal, for my untrained body. In general, everything works.
However, as we were taught in the ML-philosophy classes: practice is the criterion of truth! It is necessary to evaluate the practical value of this energy source. The assessment methodology was proposed as follows: the control battery is connected to emergency lighting until the latter goes out. After that, the battery is charged by pedaling for one hour and reconnected to the lighting. The ratio of charging time to lighting operating time can be a parameter for evaluating the efficiency of the system. 
Emergency lighting system - LED strips (remained from the renovation of the apartment) with a total length of 5.7 m, glued to the crane beam guide. Operating voltage from 12.5 V to 8 V (average 10 V), current 0.8 A. Average power consumption 8 W. If we assume that from the generated power of 28 W (7 V * 4 A) it will be possible to "store" 20 W, the expected operating time of the emergency lighting system is approx. 2.5 hours.
A pre-discharged (up to 7.5 V under load with an LED strip) battery was charged for 40 minutes. The pedals were turned in turn with the son for 5 minutes - it turned out to be not an easy task. 20 minutes on one half of the battery and 20 minutes on the other. 
After that, they connected emergency lighting to it and began to wait. Here a bitter disappointment awaited me - my calculations were not correct. After two and a half hours we drove home, leaving the LEDs on. In the morning, after 12 hours, I stopped by to check - they glow, infections. After another 8 hours, they almost did not glow - the voltage under load dropped to 7.5 V.
In general, after a 40-minute recharging with a bicycle generator, the operating time was about 20 hours. Somewhere I made a mistake But the main thing is that the result has been achieved. Having such a device, you can provide yourself with electricity sufficient for modest lighting and the operation of not very powerful devices. An hour of an exercise bike - a day with light
Practical advice for those wishing to repeat the experience:
A bike with gear shifting is highly desirable - you will start at one speed and finish at another.
Swap tires on wheels. The rear tire has a developed tread, along which the alternator pulley jumps, constantly bounces and loses drive.
Do not use a solid-state relay regulator - the excitation winding of an automobile alternator is designed for more power than the output stage of a motorcycle relay. This is how I burned the relay from Java. 
It is necessary to control the charging process with a voltmeter (for example, at least 6.5-7 V), an ammeter (± current) or a control light (some relays allow you to set it).
If you stop to rest - remove the terminal from the battery, discharging through a relay with a generator will quickly devour your work.
motor generator located on the left of the circuit, the output voltage (+/-12 V) is on the right. Any load can be connected to the output: light bulbs, fluorescent lamps, LED lighting equipment, radio, portable mobile phone charger, TV, satellite receiver, inverter. All connected devices must be rated for 12 V.
Let's analyze the scheme in more detail. Bicycle The generator produces 3-phase alternating current, which must be converted to direct current before use. A three-phase rectifier can be made from six diodes or purchased ready-made (used in wind energy). It looks like a regular bridge rectifier, only it has five terminals instead of four. The rectifier must be rated at least 100 V and 35 A. Each of the diodes must withstand the same voltage, but only half the current (20 A). The straightener needs some cooling - so attach it to a large piece of metal.
The output power of the rectifier cannot be directly supplied to a light bulb or TV, as a stable voltage is not generated when pedaling. It will fluctuate between zero and maximum and may damage equipment. This problem is solved by connecting a battery in parallel to the output of the rectifier, which will absorb the excess power produced by the generator and fill in the gaps when the generator does not produce enough power or even stops for a short time. The battery doesn't have to be big or special - any lead-acid battery will do. If it has a large capacity, this is also good. You can use an old 12V 16Ah computer UPS battery. For domestic use, sealed batteries that do not emit gases are recommended.
There are other components in the diagram as well. One of them is a fuse, which is needed in case of a short circuit. The battery produces such a strong current that it can even ignite the cable. A 2.5 mm2 cable and a 30 A fuse are recommended. There are also two measuring devices on the diagram (not in the photo). One voltmeter (with its own fuse) and one ammeter. Although the pedal generator works without them, a voltmeter is highly recommended for the sake of battery health. It is better to take a digital voltmeter. As soon as 14 V is displayed on it (for 12 V systems), you need to stop pedaling. Never go over 15 volts. Voltage should also never drop below 10.5 volts. An analog ammeter (zero in the middle of the scale) is not very important, but it shows whether energy is being pumped into the battery (eventually leading to a full charge of the battery) or consumption ( leading to battery drain). The circuit cannot use a digital ammeter, as the current changes too frequently, which does not allow a stable reading. The range of the ammeter depends on the current drawn by the load. Best to buy with +/-20A range.
