How to make a dynamo machine from copper wire. Start in science. Who has priority when crossing an intersection with a bicycle path?
A dynamo, or electric current generator, is a device that converts other states of energy into electrical energy: thermal, mechanical, chemical. Bicycle generators that power headlights and taillights remain popular to this day.
Operating principle of an electric current generator
A dynamo generates electrical energy through the principle of electromagnetic induction. Typically, such a device converts mechanical influences directly into electrical impulses. It consists of a rotor (an open wire winding) and a stator in which the poles of the magnet are located. The rotor, without stopping its movement, rotates all the time in a force magnetic field, which inevitably leads to the generation of current in the winding.
The dynamo represents the following diagram of its device. A rotating conductor, or rotor, crosses a magnetic field and a current is generated in it. The ends of the rotor are connected to the ring (collector), through them and the pressure brushes the current moves into the electrical network.
Electric current in a dynamo
The resulting current in the conductor will have the greatest value provided that the rotor is located perpendicular to the magnetic lines. The greater the turn of the conductor, the less current will be. And vice versa. That is, the process of rotating a conductor in a magnetic field forces the generated electric current to change direction twice during one rotation of the rotor. Thanks to this property, this type of current began to be called alternating.
A dynamo for generating direct current is built on the same principle as for alternating current. The difference can only be noticed in the details, when the ends of the metal wire are not fixed to rings, but connected to half rings. Such half-rings are necessarily insulated from each other, which, when the conductor rotates, makes it possible to alternately contact one half-ring and then the other with the brush. This means that the generated current will flow into the brushes exclusively in one direction, in a word - the current will be constant.
How to assemble a dynamo?
A DIY dynamo can be assembled quickly. The basis for the future generator will be a wooden board about 30 mm thick and an area of 150 by 200 mm. The housing is attached to it with two screws so that the electromagnets are positioned horizontally, one against the other. Then, through the bearing attached to the housing, the armature axis is threaded, which is fixed in place between the electromagnets. Brushes are threaded through the inside of the bearing frame and the second end of the armature axis is inserted. The collector is fixed at this end.
Before attaching the bearing frame to the base, the armature must be aligned so that its rotation between the electromagnets does not touch them. The brushes should be located across the shoes of the electromagnets and secured to the bearing. A small pulley is attached to the free end of the rotor.
Electrical installation of the device consists of connecting the ends of the windings for electromagnets with brushes. Also, pieces of flexible wire are connected to them to communicate the device with an external circuit.
Generator and bicycle
A bicycle dynamo demonstrates its power depending on the rotation speed. For example, 
If the bicycle is not spinning fast enough or if it stops, the power to the light or other device will stop. But at high speeds, the light bulbs can burn out before their service life.
There are several types of bicycle electric generators:
The hub type is built into the wheel hub. Structurally, it consists of a static core on an axis and a reversing multi-pole magnet in the shape of a ring. Their cost is higher, which is offset by quiet operation and efficiency.
The bottle type is the most popular. The bottle-shaped device is equipped with a small wheel that is driven by friction against the sidewall of the rubber tire of the wheel.
The carriage generator is installed next to the carriage cup, below the frame stays. The movement of the spring-loaded roller is due to friction against the tire tread. It should be mentioned that the bottom bracket and bottle dynamo machine will stop working when exposed to wet conditions.
Those who still remember their school days probably haven’t forgotten the feeling of being involved in a small miracle in a physics lesson, where the teacher clearly demonstrated the transformation of muscle muscle into electricity. Modest in size and capabilities, the dynamo, without any wires, sockets or batteries, turned the handle on and lit a light bulb - and the faster the handle was rotated, the brighter it burned.
The feeling of miracle, however, was mixed with healthy skepticism: the age of electricity, sockets at almost every step, batteries in stacks. So is it worth working with your hands and feet if they are the fruits of great discoveries?
But what will you do if you get lost in three pines and discover that the charge of your newfangled gadget or even an old mobile phone is running low?
By the way, those who drove recklessly on two-wheeled vehicles in childhood are very familiar with the idea, which is already more than a century and a half old. The simplest dynamo for a bicycle, assembled literally on the knee and mounted on the front wheel, fed a flashlight bulb from the free energy of pedaling, which illuminated the road as it glowed.
The merits of Faraday's discovery were also appreciated by the military. In fact, a battery only has value as long as it has charge. Having spent it, it turns into a useless heavy object, instead of which it is better to take another zinc with cartridges. Need energy? What about the soldier? Let him turn the generator handle properly to ensure the radio works. (That’s why that generator was popularly nicknamed “soldier-motor.”)
In principle, little has changed with the advent of the era of high technology. Gadgets are gadgets, and without power supply their value is zero, especially if there is nothing to charge them in the near future. The value also disappears in cloudy weather or at night. The dynamo is more than unpretentious in this regard. If only there was a person who could turn a handle, there would be current!
The pioneers in this matter, of course, were craftsmen who were accustomed to the fact that almost everything in this world, including a dynamo, must be made with their own hands. Self-taught people did not skimp on sharing their achievements, and as a result, specialized magazines were filled with photographs and drawings of simple devices that easily recharged the batteries of flashlights, mobile phones, smartphones and GPS navigators. Fans of cycling haven't forgotten either: a long ride is enough and the “on-board” dynamo will provide a full charge for your iPhone or iPad.
Finally, having seen the benefits of the practical use of visual aids from their school years, professional producers followed the amateurs. Now there are enough portable devices on the market that convert the user's muscular energy into electric current for almost any electronics. For example, a small LED flashlight that fits in the palm of your hand has a folding handle. It is enough to rotate it for a minute at a speed of two revolutions per second for the device to shine for several minutes.
It is also very pleasing that in parallel with this equipment, a dynamo is also being sold, specially designed for teenagers interested in science. By endlessly experimenting at home, you can not only figure out how to get environmentally friendly electricity without batteries, but also invent something new...
Now a lot of digital equipment is breaking down, computers, printers, scanners. Time is like this - the old is replaced by the new. But equipment that has failed can still serve, although not all of it, but certain parts of it for sure.
For example, stepper motors of various sizes and powers are used in printers and scanners. The fact is that they can work not only as motors, but also as current generators. In fact, this is already a four-phase current generator. And if you apply even a small torque to the engine, a significantly higher voltage will appear at the output, which is quite enough to charge low-power batteries.
I propose to make a mechanical dynamo flashlight from a stepper motor of a printer or scanner.
Making a flashlight
The first thing you need to do is find a suitable small stepper motor. Although, if you want to make a flashlight larger and more powerful, take a large engine.
Next I need a body. I took it ready. You can take soap dishes, or even glue the case yourself.
We make a hole for the stepper motor.
We install and try on the stepper motor.
From an old flashlight we take the front panel with reflectors and LEDs. Of course, you can do all this yourself.
We cut out a groove for the headlight.
We install a luminary from an old flashlight.
We make a cutout for the button and install it in the groove.
In the free area we place the board on which the electronic components will be placed.
Flashlight electronics
Scheme
In order for LEDs to shine, they need constant current. The generator produces alternating current, so a four-phase rectifier is needed that will collect current from all motor windings and concentrate it in one circuit.Next, the resulting current will charge the batteries, which will store the resulting current. In principle, you can do without batteries - using a powerful capacitor, but then the glow will only appear at the moment the generator is turned.
Although there is another alternative - to use an ionistor, it will take considerable time to charge it.
We assemble the board according to the diagram.
All parts of the flashlight are ready for assembly.
Lantern dynamo assembly
We attach the board with self-tapping screws.
We install the stepper motor and solder its wires to the board.
We connect the wires to the switch and headlight.
Here is the almost assembled lantern with all the parts.
Everyone is familiar with the situation - you are waiting for an important call and then you have bad luck, the phone battery is dead, and you are on the street. Today, of course, you can find alternative chargers on the market, in particular those based on solar batteries. But as a rule, solar batteries have low efficiency (no more than 15-17%) and do not have time to charge a mobile phone, and sometimes the charging process takes up to 6 hours.
You can, of course, use chargers from one AA battery, but as a rule, such devices are intended only for recharging, and the battery quickly discharges.
As a result, it was decided to assemble a compact charger with a built-in DC generator. It is known that to charge low-power autonomous devices (mobile phones, receivers, players, etc.) you need to have an operating voltage of at least 4.5-4.8 volts, therefore you need to use appropriate batteries, but they take up a lot of space, so it was decided to use DC- DC voltage converter 1.5-6 volts. The converter was used ready-made, from a charger on one battery (purchased for 130 rubles). The converter is quite compact and has a high efficiency below the parameters of the converter.
Input voltage – 1.2-1.7 volts
Current consumption - up to 2 amperes
Output voltage - 5.5 volts
Output current - up to 500 mA
The inductor is convenient to wind on a ring from an energy-saving lamp; it contains 9 turns of 0.3mm wire
The essence of the device's operation is quite simple - the generator rotates, charges the built-in battery, when a load (in our case, a telephone) is connected to the output of the converter, the latter turns on and charges it. During the charging process, you can recharge the backup source by rotating the generator.
An electric motor from a cassette player was used as a generator. At 2500 rpm, the generator is capable of producing up to 8 volts of voltage at a current of up to 850 mA! Agree, a lot for such a baby.
In order to provide the required number of revolutions, a gearbox was used. Fortunately, I found an old toy with a built-in gearbox, the number of gears is only 2, but this is enough to properly charge the backup battery. Such a “gearbox” can be made from the drive of an unnecessary DVD player or computer, everything you need is there, the main thing is to provide the generator with more than 300 rpm, at such revolutions it freely produces 2 -2.5 volts, which is enough to charge the backup source.
One can of a nickel-metal hybrid battery with a voltage of 1.2 volts and a capacity of 1200 mA was used as a backup source, although batteries with any capacity can be used. A diode must be connected to the positive side of the generator in the forward direction to prevent reverse voltage from being supplied to the generator, otherwise the latter will operate as an electric motor.
The basis is a high-quality DC-DC converter on the ZHDZ5 chip.
The microcircuit is quite common; it can be purchased at a radio store for $1, although you can also buy a ready-made battery charger for only $3.
The peculiarity of this converter is that it turns on only when a load is connected to the output, this was discussed at the beginning of the article. 007G, also known as MMBR5031LT1, is a high-frequency silicon NPN transistor. The circuit itself is simple and provides high efficiency; all components are in SMD design, which is why everything is so miniature.
The finished device should be supplemented with a socket for connecting charging cables of various autonomous devices. The result is a fairly compact universal charger that will always help out, regardless of weather conditions and other factors.
List of radioelements
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad |
|---|---|---|---|---|---|---|
| Chip | NCP1400A | 1 | Marking: ZHDZ5 | To notepad | ||
| Transistor | MMBR5031LT1 | 1 | Marking: 007G | To notepad | ||
| Schottky diode | SS14 | 1 | To notepad | |||
| Capacitor | 70 nF | 1 |
Task 1 of 15
1 .
Are the Rules broken in the situations depicted?
Right
f) tow bicycles;
Wrong
6. Requirements for cyclists
6.6. A cyclist is prohibited from:
d) while driving, hold on to another vehicle;
f) tow bicycles;
Task 2 of 15
2 .
Which cyclist doesn't break the rules?
Right
6. Requirements for cyclists
6.6. A cyclist is prohibited from:
Wrong
6. Requirements for cyclists
6.6. A cyclist is prohibited from:
b) move on highways and roads for cars, as well as on the roadway if there is a bicycle path nearby;
Task 3 of 15
3 .
Who should give way?
Right
6. Requirements for cyclists
Wrong
6. Requirements for cyclists
6.5. If a bicycle lane crosses a road outside an intersection, cyclists must give way to other vehicles traveling on the road.
Task 4 of 15
4 .
What loads is a cyclist allowed to carry?
Right
6. Requirements for cyclists
22. Cargo transportation
Wrong
6. Requirements for cyclists
6.4. A cyclist may only carry such loads that do not interfere with the operation of the bicycle and do not create obstacles for other road users.
22. Cargo transportation
22.3. Transportation of cargo is permitted provided that it:
b) does not interfere with the stability of the vehicle and does not complicate its control;
Task 5 of 15
5 .
Which cyclists violate the Rules when transporting passengers?
Right
6. Requirements for cyclists
6.6. A cyclist is prohibited from:
Wrong
6. Requirements for cyclists
6.6. A cyclist is prohibited from:
e) carry passengers on a bicycle (except for children under 7 years old, transported on an additional seat equipped with securely fastened footrests);
Task 6 of 15
6 .
In what order will vehicles pass through the intersection?
Right
16. Driving through intersections
Wrong
16. Driving through intersections
16.11. At an intersection of unequal roads, the driver of a vehicle moving on a secondary road must give way to vehicles approaching this intersection of carriageways on the main road, regardless of the direction of their further movement.
16.12. At the intersection of equivalent roads, the driver of a non-rail vehicle is obliged to give way to vehicles approaching from the right.
Tram drivers should follow this rule among themselves. At any unregulated intersection, a tram, regardless of the direction of its further movement, has an advantage over non-rail vehicles approaching it along an equivalent road.16.14. If the main road at an intersection changes direction, drivers of vehicles moving along it must follow the rules for driving through intersections of equivalent roads.
This rule should be followed among themselves and by drivers driving on secondary roads.Task 7 of 15
7 .
Riding bicycles on sidewalks and pedestrian paths:
Right
6. Requirements for cyclists
6.6. A cyclist is prohibited from:
Wrong
6. Requirements for cyclists
6.6. A cyclist is prohibited from:
c) move on sidewalks and pedestrian paths (except for children under 7 years old on children's bicycles under the supervision of adults);
Task 8 of 15
8 .
Who has the right of way when crossing a bike path?
Right
6. Requirements for cyclists
6.5. If a bicycle lane crosses a road outside an intersection, cyclists must give way to other vehicles traveling on the road.
Wrong
6. Requirements for cyclists
6.5. If a bicycle lane crosses a road outside an intersection, cyclists must give way to other vehicles traveling on the road.
Task 9 of 15
9 .
What distance should be between groups of cyclists moving in a column?
Right
6. Requirements for cyclists
Wrong
6. Requirements for cyclists
6.3. Cyclists traveling in groups must ride one after another so as not to interfere with other road users. A column of cyclists moving along the roadway must be divided into groups (up to 10 cyclists in a group) with a movement distance between groups of 80-100 m.
Task 10 of 15
10 .
Vehicles will pass through the intersection in the following order
Right
16. Driving through intersections
16.11. At an intersection of unequal roads, the driver of a vehicle moving on a secondary road must give way to vehicles approaching this intersection of carriageways on the main road, regardless of the direction of their further movement.
Wrong
16. Driving through intersections
16.11. At an intersection of unequal roads, the driver of a vehicle moving on a secondary road must give way to vehicles approaching this intersection of carriageways on the main road, regardless of the direction of their further movement.
16.13. Before turning left and making a U-turn, the driver of a non-rail vehicle must give way to a tram in the same direction, as well as to vehicles moving on an equivalent road in the opposite direction straight or to the right.
Task 11 of 15
11 .
A cyclist passes an intersection:
Right
16. Driving through intersections
Wrong
8. Traffic regulation
8.3. Traffic controller signals take precedence over traffic light signals and road sign requirements and are mandatory. Traffic lights, other than flashing yellow ones, take precedence over priority road signs. Drivers and pedestrians must comply with the additional requirements of the traffic controller, even if they contradict traffic lights, road signs and markings.
16. Driving through intersections
16.6. When turning left or turning around when the main traffic light is green, the driver of a non-rail vehicle is obliged to give way to a tram in the same direction, as well as to vehicles moving straight in the opposite direction or turning right. Tram drivers should follow this rule among themselves.
Task 12 of 15
12 .
Flashing red signals of this traffic light:
Right
8. Traffic regulation
Wrong
8. Traffic regulation
8.7.6. To regulate traffic at railway crossings, traffic lights with two red signals or one white-lunar and two red ones are used, having the following meanings:
a) flashing red signals prohibit the movement of vehicles through the crossing;
b) a flashing white-lunar signal indicates that the alarm system is working and does not prohibit vehicle movement.
At railway crossings, simultaneously with the prohibitory traffic light signal, an audible signal may be turned on, additionally informing road users that movement through the crossing is prohibited.
Task 13 of 15
13 .
The driver of which vehicle will cross the intersection second?
Right
16. Driving through intersections
16.11. At an intersection of unequal roads, the driver of a vehicle moving on a secondary road must give way to vehicles approaching this intersection of carriageways on the main road, regardless of the direction of their further movement.
16.14. If the main road at an intersection changes direction, drivers of vehicles moving along it must follow the rules for driving through intersections of equivalent roads.
This rule should be followed among themselves and by drivers driving on secondary roads.
Wrong
16. Driving through intersections
16.11. At an intersection of unequal roads, the driver of a vehicle moving on a secondary road must give way to vehicles approaching this intersection of carriageways on the main road, regardless of the direction of their further movement.
16.14. If the main road at an intersection changes direction, drivers of vehicles moving along it must follow the rules for driving through intersections of equivalent roads.
This rule should be followed among themselves and by drivers driving on secondary roads.
16 Driving through intersections
Wrong
8. Traffic regulation
8.7.3. Traffic light signals have the following meanings:
A signal in the form of an arrow that allows a left turn also allows a U-turn if it is not prohibited by road signs.
A signal in the form of a green arrow(s) in the additional section(s), switched on together with the green traffic light signal, informs the driver that he has priority in the direction(s) of movement indicated by the arrow(s) over vehicles moving from other directions;
f) a red signal, including a flashing one, or two red flashing signals prohibit movement.
A signal in the form of a green arrow(s) in the additional section(s), together with a yellow or red traffic light signal, informs the driver that movement is permitted in the indicated direction, subject to the unhindered passage of vehicles moving from other directions.
A green arrow on a sign installed at the level of a red traffic light with a vertical arrangement of signals allows movement in the indicated direction when the red traffic light is on from the rightmost lane (or the leftmost lane on one-way roads), subject to the provision of priority in traffic to its other participants moving from other directions to a traffic light signal allowing movement;
16 Driving through intersections
16.9. While driving in the direction of the arrow turned on in the additional section simultaneously with a yellow or red traffic light, the driver must give way to vehicles moving from other directions.
When driving in the direction of the green arrow on the table installed at the level of the red traffic light with vertical signals, the driver must take the extreme right (left) lane and give way to vehicles and pedestrians moving from other directions.
