Metal cutting with laser is the most advanced and modern technology, but also the most expensive. Its main advantage is the beam, with unlimited possibilities. Do-it-yourself laser cutting of metal makes it possible to cut workpieces in any direction, while the cut edges will be neat and do not require further processing. In addition, the laser beam is monochrome, that is, it has a clear and strict wavelength (it is fixed) and a constant frequency. This makes it easy to focus even with ordinary lenses.
So, equipment for laser cutting of metal is a thing that is inaccessible to many; it is too expensive. Therefore, home craftsmen get out of the situation by using various almost unnecessary items, from which a homemade device is made. There are many options for making laser cutters with your own hands, one of them is based on the use of a laser pointer, which will be discussed.
Making a homemade laser cutter
To assemble the cutter you will need:
- laser pointer;
- flashlight;
- CD/DVD-RW – not necessarily new, the main thing is that it has a working laser with a drive;
- tools: soldering iron and screwdrivers.
Please note that a DVD writer is required to assemble the laser cutting machine. You need to disassemble it and find a carriage with a laser that writes and reads information from the compact disk. There should be a red diode next to the carriage. It also needs to be removed with a soldering iron, because it is soldered to the circuit in the plateau. By the way, the diode must be handled carefully; you cannot shake it, drop it, hit it, etc.
Now here's the point - a laser cutter (aka diode) consumes more current than the diode of a laser line. Therefore, care must be taken to ensure that there is more of this current. There are several options here, but since a flashlight was prepared, its batteries will be used to power the diode. Battery in laser pointer less and she's alone.
Now you can proceed to assembling the laser cutter.
- The laser pointer is disassembled.
- Its diode is removed from it, and a diode removed from the DVD is installed in its place.
- Now you need to connect to a new, more powerful power source. To do this, the front part of the pointer is installed in the flashlight, having first removed the lens from it. It is secured to the device using a clamping nut screwed onto the thread.
- The diode is connected by wires from the terminals that connect to the batteries. It is important here not to confuse the polarity of the connection.
- Basically, everything is ready. A miniature laser cutter can be used.
Of course, they won’t be able to cut metal, but paper and polymer films will be burned through. Even matches can be lit with this device.
Laser for cutting metal
By adding several devices to those used above, you can make a more powerful device, almost 500 times more powerful. Added:
- an optical collimator is a device that creates a light flux from parallel beams;
- capacitors 100pF and 100mF;
- one resistor with a resistance of 2-5 Ohms.
A driver is assembled from radio components together with a diode, which will output the cutter to the required power. The optical collimator has a place where you can install a diode, and this is its great advantage. That is, instead of a laser pointer, this installation uses a collimator. In addition, the pointer is made of plastic, and during the cutting process its body will become very hot. This will lead to its warping, and the installation itself will not cool well.
All other assembly technology is exactly the same as in the previous case. It should be noted that the diode is a very sensitive element, so it is necessary to remove static electricity from it before use. This can be done using an antistatic wrist strap. If you don’t have a bracelet, you can wind a thin wire around the diode, which will remove static from the part.
Making a laser with your own hands for cutting metal requires certain actions that affect its quality functionality. First of all, you need to test the assembled driver. To do this, you will have to find another exactly the same diode. It is connected to the device and tested with a multimeter. 300-350 mA is the norm for many homemade devices. But if there is a need to increase the power of the entire unit, then it is better if the multimeter shows 500 mA. True, for such a cutter you will have to assemble another driver that supports this current value.
Let's not forget about the aesthetic side of the issue. You can come up with different housing options. For example, a small LED flashlight. It is recommended to store the finished device in a special case so that the optical collimator lens does not become covered with dust. By the way, such a cutter may cause law enforcement there are a lot of questions, so you shouldn’t carry it around in your pocket.
It should be noted that the diode power depends on the current, not the voltage. When the latter increases, the standard brightness of the diode is exceeded, and this leads to destruction of the resonator in the diode design. That is, the light source stops heating, which is necessary for a laser cutter. It just glows like a regular light bulb. Temperatures also affect the performance of the diode. At low temperatures its performance increases; at high temperatures, the resonator fails.
Hi all. After purchasing a printer and understanding the operating principle of CNC machines, I began to look at other types of machines. My father wanted a router, but I was more interested in engraving. Having calculated how much a more or less sane router would cost, it became clear that an engraver would appear first. So I got a 2.5W diode laser.
I decided to make the stanina with a reserve and it turned out to be a working field of 70x60cm. The carriages and other components were printed. After I started using it, it became clear that I clearly made the working area with an excessive margin; in fact, I didn’t have to engrave more than the A4 format. Then, after one successful upgrade of the printer, I had many profiles left and from them a mini version of the engraver was assembled, clearly in A4 format, how lucky isn’t it?)) And the large frame moved to the wall where it spent six months. For engraving, I used paid software that allows me to dynamically change the speed and power of the laser, this speeded up the process many times over and the quality was excellent. Over time, I slightly changed the design by placing the engines on the frame; I didn’t like the fact that they weighed down the carriages and bent the belts. Why this epilogue? Moreover, at the time of collecting information about the cost different types lasers they announced to me that to assemble CO2 with less than $500 and don’t come near. It so happened that I had a lot of free time, and having studied CO2 laser machines in more detail, I had a misunderstanding where $500 was. After thinking about what you could do yourself using a 3D printer, an almost complete assembly of the machine was simulated in SolidWorks. The conclusion was that essentially only laser components are needed in the form of the laser tube itself, a power supply unit for it, mirrors and a lens. Everything else could be printed out or obtained)))
I decided to make the carriages on wheels, firstly, if you don’t use proprietary controllers, then the operating speed is not too high, and the laser head turned out to be very light, and if the wheels can handle the printer head, then why can’t a laser one handle it, and secondly, I simply had wheels with double reserve.
The cost of the laser component turned out to be only 12,000 rubles (including paid delivery). For testing, a laser tube with only 40 watts was ordered. I ordered from Ali, there were only 3 specialized sellers, and one clearly outweighed the orders, and after talking with him it became clear why, the managers are very sociable and quickly answer any questions. The order was placed and the agonizing wait began, brightened up by the assembly of all the other parts of the machine.
Quite a bit of various parts remains from the assembly of Re-D-Bot and its subsequent modifications. I had to order extra little things like springs and bearings with sides. Finally the large bed came in handy.
It was decided to make the body of the machine from chipboard; I wanted the mill to be compact, since there is less and less space in the workshop.
I estimated the dimensions of the body based on the dimensions of the tube; a square of 105x105 cm came out of the frame; I decided to make the height 20 cm, this was quite enough for working with materials up to 50 mm. Cutting the sheet into the body and the table on which it will stand cost 2100 rubles (including the cost of the sheet itself).
The printing of various machine components was in full swing, fortunately everything was modeled taking into account subsequent printing and this helped to avoid problems of “the component does not fit in place.” Although some components still had to be modified, for example, the head had only one freedom of adjustment, in height, but getting to the nuts for tightening cost a lot of wasted nerves, it had to be modified, it also turned out that the back part of the head carriage does not seem to have much load, but with a fair amount of tension on the belts, it simply turned out.
Speaking of degrees of freedom. The factory mirror mounts had 2-3 degrees of freedom (this is in addition to the ability to rotate the mirror), which somewhat complicated the adjustment of the mirrors. In my project, I gave them only 1 freedom, head up/down, side forward/backward, the laser mirror is also down/up, that’s all. Less mobility means less chance of making mistakes.
In the factory, the design is responsible for adjusting the focus lifting mechanism table, this option did not suit me, and I began to think about how the focus could be adjusted on the head, so a collet clamp of the sleeve with a lens inside was modeled. All parts were printed from PETG, the absence of shrinkage allows you to set the exact dimensions without worrying,
that the parts will not fit together.
I’ll say right away that this unit had to be redone, because if the lens gets dirty for some reason, it starts to get quite hot during operation, so one day the lens melted into the cylinder and was broken when trying to remove it.
The toad did not allow me to buy a ready-made head, and suddenly an old lensed flashlight caught my eye, the assembly with an LED and a driver was perfect for clamping the lens, the dimensions were the same, all that was left was to cut off the extra part of the flashlight (by the way, it was not working, the money was returned for it)). There were also problems with the blowing nozzle, it turned out that the beam heats not only a point on the surface, but also the air around it, because of this the tip was constantly melting, it was decided to make an insert, already damaged printer nozzles were perfect for this, only it was decided to drill out to 2mm hole to leave room for installation errors. The laser arrived a week before New Year's Eve, the holidays promised to be fruitful)))
A large stand turned out to be with a shaft that was supposed to synchronize the Y carriages. They promised to make it, but they constantly fed them breakfast until the 31st, and then they even said that it would only be on the 9th... The wait was unbearable and it was decided to temporarily use a pin, but since 8mm the stud is not 8mm at all, it was decided to use 5mm using bushings. This trick worked quite well (by the way, the shaft was given to me only on January 29, and it was not 8mm, but 8.2, and even crooked).
Since the laser head is quite light, NEMA17 handled its movement directly, but for the Y beam it was necessary to install pulleys, resulting in a 1:2 gear ratio. Not a lot, of course, but quite enough. I thought for a long time about cooling the tube, it was decided to use Peltier elements, but for now it’s winter next room(garage) and it’s always +10°, it was decided to simply bring the cooling pipes with the container there. The water was pumped by a small pump from Ali for 500 rubles, stated 800 l/hour, the Chinese are optimistic, but it produces about 200 and that’s enough for us.
The design was assembled and the machine finally came to life. The disadvantage of my compact design was the terrible inconvenience of adjustment; for it I had to remove side wall, otherwise you won’t be able to get to the screws. But these are all minor things. Half an hour of shooting on plywood and paper and all the mirrors were adjusted. The first cuts showed that without a hood you can only cut paper. An old 140x140mm fan was perfect for it; I don’t know what it’s made of, but it blows extremely powerfully and makes the same noise as a vacuum cleaner. The hood was tested with an electronic cigarette (it was purchased for precisely this purpose) and the result was excellent.
Next, testing began on the capabilities of the 40W tube. The results surprised me somewhat. There’s no need to talk about 4mm plywood. Only 1mm plexiglass was found; the laser cuts it even at extremely low powers. In 1 pass we managed to cut up to 8mm plywood, but slowly. It was even possible to cut 12mm, but in 3 passes, although there is no point in talking about the quality of the cut... Tests and trial products were made from rather poor grade 44 plywood, which had been lying in the garage for 2 years. When I tried to buy a good one, I found out that in my city ONLY 1 office does this and the wait is 3 weeks. I'm sitting waiting)))
Oh yes, what to talk about - the cost of the machine, taking into account the purchase of all parts, is less than 16,000 rubles. And this is with a field of 60x70cm. And the field can be of almost any size.
You can see more photos by clicking on the link to the album. I am also attaching an “estimate” with links.
Let's say this: a laser cutter for metal is like Men's Watch. A cool and unique tool, necessary for a modern man who has his own garage and knows how to do something with his own hands.
You can make this tool yourself. This is not difficult if you follow the necessary rules and instructions. The power of a homemade laser knife will not come out God knows what, but if necessary, it can be increased in several ways.
Of course, you won’t have a tool for industrial needs, but for everyday household work, yours is quite suitable.
Firstly, you can make do with scrap materials, that is, you don’t have to buy anything special in the store. The most important thing is to find an old laser pointer.
Additionally you will need:
- screwdrivers of different calibers;
- matrix with laser drive from a used DVD-ROM;
- a flashlight powered by rechargeable batteries;
- soldering iron
With great care and maximum care, we disassemble the laser pointer and disk drive. First you need to remove the drive from the computer drive.
Important nuance: this drive must be not only reading, but also writing. All drives have these properties. modern computers, so before disassembling, check the model and characteristics of the drive.
Laser cutter for metal.
The second step is to find and remove the red diode, which is used to record on the disk in the form of burning. This diode is easy to remove: you need to unsolder the fasteners with a soldering iron.
Carry out all actions with tenderness and caution: diodes and other small things associated with them are fragile things and ready to deteriorate at the slightest opportunity. Reducing the risk of breakdown is easy. To do this, just replace the diode with a red light bulb from the DVD wire.
Now we begin to make the body of the cutter from the stored flashlight and rechargeable batteries that will be needed. Using a flashlight will allow you to produce a model that is compact and comfortable to work with.
Don't forget to remove from it protective glass, since it can become an obstacle to the laser beam in the future.
The most important point during the manufacture of the body - right choice current polarity.
Now you need to power the diode by connecting it to the battery charger.
As a final step and before starting work, we check:
- Is the fixation in the clamps and latches strong;
- device polarity;
- direction and focus of the beam.
What can you do with your cutter?
Do not forget that your new homemade one is not capable of cutting thick metal - it simply cannot do it. But you can strengthen the tool to do work on almost any metal if necessary.
Drawing plasma cutting metal
First, you will need to stock up on a capacitor, because under no circumstances can a knife with increased power be connected directly to the network. Therefore, first the current must go to the capacitors and only then to the batteries.
You can increase the power using additional resistors. Your knife will receive additional power from the use of a so-called collimator, which serves to concentrate and accumulate the laser beam.
Collimators are very inexpensive and are sold in any electrical equipment department.
In the case of increasing power, the unnecessary static increases at the same time. It can be easily eliminated by winding aluminum wire around the diode.
Now we need measurements: we measure the current strength at the ends of the cutter after connecting them to the diode. The indicators are adjustable, the most suitable range is from 300 to 500 mA.
Why bother?
The gadget is cool and necessary. But dear. But making a metal cutter with your own hands is not difficult, even for beginners. So the motivation to implement our advice is obvious.
Let's better understand the principles of operation of a laser knife, this will be useful to everyone: those who bought it and those who made it with their own hands.
The main character is a focused laser beam, which, due to its directionality and radiation, acts, for example, on metal. The beam itself is extremely narrow - its diameter is very small. Thanks to this, the cuts on the workpieces are distinguished by the highest precision.
The cutting depth depends only on the power of the tool. Here, of course, professional factory models with high deepening rates win. As for our homemade laser knife, the depth here is available at 10 – 30 mm.
Scheme of operation of a gas cutter.
Metal cutters are divided into three types:
Solid cutters
Made from special glass or crystalline LEDs. These are relatively cheap models, produced and used in industry.
Fiber laser knives
In this case, optical fiber is used, making these models very efficient in terms of cutting depth. In essence, the actions resemble solid-state devices - close relatives. But more effective and more expensive.
Gas cutters
The gases used are nitrogen, carbon dioxide, and maybe helium. These models are much more effective than the two previous types. They cut everything from polymers and rubber to the most difficult metals.
It is the most progressive, but also expensive technology. But with its help you can achieve results that are beyond the power of other metal processing methods. The ability of laser beams to impart to any material the required form truly limitless.
The unique capabilities of the laser are based on the following characteristics:
- Clear directionality - due to the ideal directionality of the laser beam, the energy is focused at the point of impact with a minimum of losses,
- Monochromaticity - a laser beam has a fixed wavelength and a constant frequency. This allows it to be focused with ordinary lenses,
- Coherence – laser beams have a high level of coherence, so their resonant vibrations increase the energy by several orders of magnitude,
- Power – the above properties of laser beams ensure energy focusing highest density on a minimum area of material. This allows you to destroy or burn through any material in a microscopically small area.
Design and principles of operation
Any laser device consists of the following components:
- energy source;
- working body that produces energy;
- an optical amplifier, a fiber-optic laser, a system of mirrors that amplify the radiation of the working element.
The laser beam produces point-by-point heating and melting of the material, and after prolonged exposure - its evaporation. As a result, the seam comes out with uneven edge, evaporating material is deposited on the optics, which reduces its service life.
To obtain smooth thin seams and remove vapors, use the technique of blowing with inert gases or compressed air melt products from the laser impact zone.
Factory laser models equipped with high-grade materials can provide good indentation rates. But for household use their price is too high.
Models made at home are capable of cutting into metal to a depth of 1-3 cm. This is enough to make, for example, parts for decorating gates or fences.
Depending on the technology used, there are 3 types of cutters:
- Solid state. Compact and easy to use. The active element is a semiconductor crystal. Low-power models have quite affordable prices.
- Fiber. Glass fiber is used as the radiation and pumping element. The advantages of fiber laser cutters are high efficiency (up to 40%), long service life and compactness. Since little heat is generated during operation, there is no need to install a cooling system. It is possible to produce modular designs that allow you to combine the power of several heads. The radiation is transmitted via flexible optical fiber. The performance of such models is higher than solid-state ones, but their cost is higher.
- . These are inexpensive but powerful emitters based on the use chemical properties gas (nitrogen, carbon dioxide, helium). With their help you can weld and cut glass, rubber, polymers and metals with very high level thermal conductivity.
Homemade household laser
For execution repair work and manufacturing metal products often needed in everyday life laser cutting metal with your own hands. Therefore, home craftsmen have mastered manufacturing and successfully use hand-held laser devices.
At production cost for household needs A solid-state laser is more suitable.
Power homemade device, of course, cannot even be compared with production devices, but for use for domestic purposes it is quite suitable.
How to assemble a laser using inexpensive parts and unnecessary items.
To make a simple device you will need:
- laser pointer;
- battery-powered flashlight;
- CD/DVD-RW writer (an old and faulty one will do);
- soldering iron, screwdrivers.
How to make a handheld laser engraver
Laser cutter manufacturing process
- You need to remove the red diode from the computer disk drive, which burns the disk when recording. Please note that the drive must be a write drive.
After dismantling the upper fasteners, remove the carriage with the laser. To do this, carefully remove the connectors and screws.
To remove the diode, you need to unsolder the diode mountings and remove it. This must be done extremely carefully. The diode is very sensitive and can be easily damaged by dropping it or shaking it sharply.
- The diode contained in it is removed from the laser pointer, and the red diode from the disk drive is inserted in its place. The pointer body is disassembled into two halves. The old diode is shaken out by picking it up with the tip of a knife. Instead, a red diode is placed and secured with glue.
- It is easier and more convenient to use a flashlight as a body for a laser cutter. The upper fragment of the pointer with a new diode is inserted into it. The glass of the flashlight, which is an obstacle to the directed laser beam, and parts of the pointer must be removed.
At the stage of connecting the diode to the power supply from batteries It is important to strictly observe the polarity.
- On last stage check how securely all the laser elements are fixed, the wires are connected correctly, the polarity is observed and the laser is level.
The laser cutter is ready. Because of low power It cannot be used when working with metal. But if you need a device that cuts paper, plastic, polyethylene and other similar materials, then this cutter is quite suitable.
How to increase laser power for metal cutting
Make more powerful laser To cut metal with your own hands, you can equip it with a driver assembled from several parts. The board provides the cutter with the required power.
The following parts and devices will be needed:
- CD/DVD-RW writer (an old or faulty one will do), with a writing speed of more than 16x;
- 3.6 volt batteries – 3 pcs.;
- 100 pF and 100 mF capacitors;
- resistance 2-5 Ohm;
- collimator (instead of a laser pointer);
- steel LED lamp;
- soldering iron and wires.
You cannot connect a current source to the diode directly, otherwise it will burn out. The diode draws power from current, not voltage.
The beams are focused into a thin beam using a collimator. It is used instead of a laser pointer.
Sold at an electrical goods store. This part has a socket where the laser diode is mounted.
The assembly of the laser cutter is the same as the model described above.
To remove static from the diode, wind it around it. Antistatic bracelets can be used for the same purpose.
To check the operation of the driver, use a multimeter to measure the current supplied to the diode. To do this, connect a non-working (or second) diode to the device. For most homemade devices, a current of 300-350 mA is sufficient.
If you need a more powerful laser, the indicator can be increased, but not more than 500 mA.
It is better to use an LED flashlight as a homemade housing. It is compact and convenient to use. To prevent the lenses from getting dirty, the device is stored in a special case.
Important! A laser cutter is a kind of weapon, so it should not be pointed at people, animals, or given to children. Carrying it in your pocket is not recommended.
It should be noted that do-it-yourself laser cutting of thick workpieces is impossible, but it can cope with everyday tasks.
It's no secret that each of us as a child wanted to have a device like a laser machine that could cut metal seals and burn through walls. IN modern world this dream can easily come true, since it is now possible to build a laser with the ability to cut various materials.
Of course, at home it is impossible to make a laser machine so powerful that it will cut through iron or wood. But with the help homemade device Can cut paper, polyethylene seal or thin plastic.
Using a laser device, you can burn various patterns on sheets of plywood or wood. It can be used to illuminate objects located in remote areas. The scope of its application can be both entertaining and useful in construction and installation work, not to mention the realization of creative potential in the field of engraving on wood or plexiglass.
Cutting laser
Tools and accessories you will need to make your own laser:
Figure 1. Laser LED circuit diagram.
- faulty DVD-RW drive with a working laser diode;
- laser pointer or portable collimator;
- soldering iron and small wires;
- 1 Ohm resistor (2 pcs.);
- capacitors 0.1 µF and 100 µF;
- AAA batteries (3 pcs.);
- small tools such as a screwdriver, knife and file.
These materials will be quite sufficient for the upcoming work.
So, for a laser device, first of all, you need to select a DVD-RW drive with a mechanical breakdown, since the optical diodes must be in good condition. If you do not have a worn-out drive, you will have to purchase it from people who sell it for spare parts.
When purchasing, keep in mind that most drives from the manufacturer Samsung are unsuitable for the manufacture of cutting lasers. The fact is that this company produces DVD drives with diodes that are not protected from external influences. The lack of a special housing means that the laser diode is subject to thermal stress and contamination. It can be damaged with a light touch of your hand.
Figure 2. Laser from a DVD-RW drive.
The best option for a laser would be a drive from the manufacturer LG. Each model is equipped with a crystal with varying degrees of power. This indicator is determined by the writing speed of dual-layer DVDs. It is extremely important that the drive be a recording drive, since it contains infrared emitter, which is needed to make a laser. A regular one will not work, since it is intended only for reading information.
DVD-RW with a 16X recording speed is equipped with a red crystal with a power of 180-200 mW. The 20X speed drive contains a 250-270 mW diode. High-speed recording devices of the 22X type are equipped with laser optics, the power of which reaches 300 mW.
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Disassembling the DVD-RW drive
This process must be done with great care because internal parts They have a fragile structure and are easy to damage. After dismantling the case, you will immediately notice required part, it looks like a small piece of glass located inside a mobile carriage. Its base needs to be removed; it is shown in Fig. 1. This element contains an optical lens and two diodes.
At this stage, you should immediately warn that the laser beam is extremely dangerous to human vision.
If it hits the lens directly, it damages the nerve endings and the person may remain blind.
The laser beam is blinding even at a distance of 100 m, so it is important to watch where you point it. Remember that you are responsible for the health of others while such a device is in your hands!
Figure 3. LM-317 chip.
Before you begin, you need to know that the laser diode can be damaged not only by careless handling, but also by voltage surges. This can happen in a matter of seconds, which is why diodes operate based on a constant source of electricity. When the voltage increases, the LED in the device exceeds its brightness standard, as a result of which the resonator is destroyed. Thus, the diode loses its ability to heat, it becomes an ordinary flashlight.
The crystal is also affected by the temperature around it; as it drops, the laser performance increases at a constant voltage. If it exceeds the standard norm, the resonator is destroyed according to a similar principle. Less commonly, the diode is damaged by sudden changes, which are caused by frequent switching on and off of the device over a short period.
After removing the crystal, you must immediately tie up its ends with exposed wires. This is necessary to create a connection between its voltage outputs. To these outputs you need to solder a small capacitor of 0.1 µF with negative polarity and 100 µF with positive polarity. After this procedure, you can remove the wound wires. This will help protect the laser diode from transients and static electricity.
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Nutrition
Before creating a battery for the diode, it is necessary to take into account that it must be powered from 3V and consumes up to 200-400 mA, depending on the speed of the recording device. Avoid connecting the crystal directly to batteries as this will not simple lamp. It can deteriorate even under the influence of ordinary batteries. The laser diode is a self-contained element that is supplied with electricity through a regulating resistor.
The power supply system can be configured in three ways with varying degrees of complexity. Each of them requires recharge from a constant voltage source (batteries).
The first method involves electrical regulation using a resistor. The internal resistance of a device is measured by detecting the voltage as it passes through the diode. For drives with a 16X write speed, 200 mA will be sufficient. If this indicator increases, there is a possibility of damaging the crystal, so you should stick to the maximum value of 300 mA. It is recommended to use a telephone battery or AAA batteries as a power source.
The advantages of this power supply are simplicity and reliability. Among the disadvantages are the discomfort when regularly recharging the battery from the phone and the difficulty of placing batteries in the device. In addition, it is difficult to determine the right moment to recharge the power source.
Figure 4. LM-2621 chip.
If you use three AA batteries, this circuit can be easily installed in a Chinese-made laser pointer. The finished design is shown in Fig. 2, two 1 Ohm resistors in sequence and two capacitors.
For the second method, the LM-317 chip is used. This method of arranging a power system is much more complicated than the previous one; it is more suitable for stationary type laser installations. The scheme is based on the manufacture of a special driver, which is a small board. It is designed to limit the electric current and create the necessary power.
The connection circuit of the LM-317 microcircuit is shown in Fig. 3. It will require elements such as a 100 ohm variable resistor, 2 10 ohm resistors, a 1H4001 series diode and a 100 μF capacitor.
A driver based on this circuit maintains electrical power (7V) regardless of the power source and ambient temperature. Despite the complexity of the device, this circuit is considered the simplest for assembly at home.
The third method is the most portable, making it the most preferred of all. It provides power from two AAA batteries, maintaining a constant voltage level supplied to the laser diode. The system maintains power even when the battery level is low.
When the battery is completely discharged, the circuit will stop functioning, and a small voltage will pass through the diode, which will be characterized by a weak glow of the laser beam. This type of power supply is the most economical, its efficiency factor is 90%.
To implement such a power system, you will need an LM-2621 microcircuit, which is housed in a 3x3 mm package. Therefore, you may encounter certain difficulties during the period of soldering parts. The final size of the board depends on your skills and dexterity, since the parts can be placed even on a 2x2 cm board. The finished board is shown in Fig. 4.
The choke can be taken from a regular power supply for a desktop computer. A wire with a cross-section of 0.5 mm is wound onto it with a number of turns of up to 15 turns, as shown in the figure. The throttle diameter from the inside will be 2.5 mm.
Any Schottky diode with a value of 3 A is suitable for the board. For example, 1N5821, SB360, SR360 and MBRS340T3. The power supplied to the diode is adjusted by a resistor. During the setup process, it is recommended to connect it to a 100 Ohm variable resistor. When testing functionality, it is best to use a worn or unwanted laser diode. The current power indicator remains the same as in the previous diagram.
Having selected the most suitable method, you can upgrade it if you have the necessary skills to do so. The laser diode must be placed on a miniature heatsink so that it does not overheat when the voltage increases. After completing the assembly of the power system, you need to take care of installing the optical glass.
