How to convert the battery charger of an electric screwdriver into a power pack
an electric screwdriver is much more practical than an ordinary screwdriver. It can be used anywhere with little effort on the part of the owner. The advantage is that it saves time. While a person with a screwdriver will unscrew one screw, the power tool will handle ten! Tool chargers sometimes break: it happens because of voltage fluctuations, expiration of the shelf life (2 to 5 years), water or household chemicals on them. A new charger costs from 1 to 10 thousand, depending on the model of the tool. Is it possible to make a power supply for an electric screwdriver 18v with your own hands, so that the unit will work from the mains? Yes, you will need a basic knowledge of electronics and practical tips. You can make a power supply for an electric screwdriver from an energy-saving light bulb, a computer or car battery.
Cordless electric screwdriver: figure it out
Structurally, a cordless electric screwdriver consists of the following elements:
An electric screwdriver with a power unit will be indispensable for the homeowner. While a screwdriver will unscrew one screw, an electric tool can handle ten
- the starter button;
- A lever that reverses the direction of the device;
Why convert a wireless device to a corded device? The batteries inside the unit last a limited amount of time (about a year with constant use). Change the batteries. an expensive event (one battery will cost at least a thousand and not the fact that will work for a long time).
Already after 3-4 months of use, the battery begins to “sit down” quickly. Then the device needs constant recharging, which, at the very least, annoys the owner.
Power supply for an electric screwdriver: preparation for conversion
Experienced repairmen advise placing the power supply for the electric screwdriver inside the product. This prevents dust, dirt, and liquids from getting on it, which means it will last longer. At this stage, you need to open the collapsible housing. To open, take a penknife and go over the seam.
Open the case of an electric screwdriver to mount the power supply will help a knife. Use it on the connecting seams to loosen the fasteners
- To understand where to place the power supply;
- Find out what voltage to work with (there are markings inside, usually 12-18 volts);
- determine how to install it.
At this stage you need to think about what you will create a new power pack from.
For this purpose, energy-saving bulbs, elements from any car or computer, special devices from electronics stores will do.
12-18 volt power supply from an energy-saving bulb
Energy-saving LED light bulbs, the parts of which are suitable for creating a power supply unit, consists of:
- From a tube with an inert gas inside. The tube is treated with phosphor;
- Plastic housings;
- electric board;
- the part where the wires are placed;
- the base, thanks to which the bulb is connected to the electrical source.
Even a broken, used energy-saving bulb is good enough to make a power pack.
To create a power supply of an electric screwdriver from a light bulb you need two of its parts: the cap and the part with the wires. The body of the bulb itself can be broken
The main thing is that the base and the part with the wires were not destroyed. To increase the power, a winding of copper wire is added to the base. Next, a power cord is attached to it with a plug for plugging into the socket at the end.
Observe the polarity, for this purpose, study the markings of the wires. A blowtorch is needed for the connection. The renewed base along with the bulb housing is placed inside the electric screwdriver, where the battery was previously located. Then the body of the device is assembled. To make the tool durable, the joints of the joints are smeared with superglue.
From a car battery and a computer battery
It is advised to use a car battery in extreme cases. It is not too powerful for an electric screwdriver, so the device will function slowly. The car battery has wires that connect to the clamps inside the electric screwdriver. Why this method is not the most convenient?
Car battery is not able to boast modest size, it is 5 times larger than the tool itself, it is inconvenient and difficult to operate, you will have to carry it to where you need a power tool.
Computer power supplies are equipped with fans and emergency shutoff buttons that work on the principle of RCDs. In the case of a short circuit of the network, the electric screwdriver will be saved from premature failure.
All power supplies from computers are equipped with a RCD. The device is able to protect the electric screwdriver from premature failure in the future
The computer unit can be used on the principle of an autobattery or in a built in electric screwdriver body. In the latter case, you will have to disassemble the power supply, remove the transformer, solder the power cord to it, install the system in the case of an electric screwdriver.
Tips for Using an Electric Screwdriver
When the 12-18 volt power supply is assembled, the electric screwdriver becomes a network screwdriver. Use it correctly:
- Every 20 minutes of work, take a break for 3-5 minutes to allow the block element to cool down;
- if you use an external unit, make sure it is clean. It must not be dusty, dirty. This way the device will heat up faster and work less efficiently;
- It is forbidden to use an upgraded tool at a height of more than 200 centimeters;
- equip the element with a safety cutoff device. If there are problems with the network, a RCD will save the equipment from breakage;
- All wires must be firmly soldered.
Technically, making a power supply for an electric screwdriver is not difficult. This will cause the tool to heat up more quickly and work less efficiently;. Be very careful how you use it. Securely solder the wires. Use car batteries only as a last resort. they are not convenient to use, too bulky and low-power.
DIY Lithium Battery Charger for Electric Screwdriver Batteries
The charger for an electric screwdriver. how to choose and whether you can make it yourself
electric screwdriver are found in all where simple repairs are made. Any electric appliance needs a stationary electricity on other words power supply. Since cordless screwdrivers are very useful, an additional battery charger is needed.
It comes with a drill, not like any electrical device can fail. What you do not face with the problem of dysfunctional equipment, let’s study the general description of chargers for an electric screwdriver.
Analog with integrated power supply
Their popularity is justified by their low price. If the drill (electric screwdriver) is not created for professional use, the duration of work is not the 1st issue. Advantages of automation. Automated ice drill from an electric screwdriver with their own hands has a number of advantages. The task of the usual charger. to get a constant voltage with a sufficient current load to charge the battery.
Works this charger following the principle of a normal regulator. For example, let’s look at the circuit of the battery charger for 9-11 volts. The type of battery is not important.
Such a power supply (aka charger) can be assembled with your own hands. Solder the circuit of course on a universal mounting plate. To dissipate the heat of the regulator’s microcircuit, a copper heat sink of 20 cm² is sufficient.
The input transformer (Tr1) reduces the AC voltage of 220 volts to a value of 20 volts. The transformer capacity is calculated by the current not voltage at the charger output. Then the alternating current is rectified with a diode bridge VD1. Usually Russian car industry (especially Chinese) use Schottky diode assembly.
After rectifying the current will be pulsating, it’s harmful for the production activity of the circuit. Pulsations are smoothed by the filtering electrolytic capacitor (C1).
The role of the regulator does chip KR142EN, in radio amateur slang. “krenka”. To get 12 volts, the index of the chip must be 8B. Control is built on transistor (VT2) not trim resistors.
There is no automation in similar devices, the battery charging time is determined by the user. To control the charge a light circuit is assembled on the transistor (VT1) not the diode (VD2). When the charging voltage is reached, the indicator (LED HL1) goes out.
advanced systems have a switch that turns the voltage off at the end of the charge in the form of an electronic switch.
In the set with economy class screwdrivers (made in Celestial Empire), there are no more extraordinary chargers. It is simple, that percentage of failure is high enough. The owner faces the prospect of being left with a relatively new inoperable electric screwdriver.
According to the attached circuit diagram, you can build a battery charger for electric screwdriver without the help of others, which will last longer than the factory. Paving Tile Technology Step by Step Planning. At this stage it is necessary to determine the future site for laying paving tiles with their own hands and create its plan.
By changing the transformer instead of the regulator, you can easily find the right value for your battery.
Analog with external power supply
The circuit of the battery charger itself is primitive, with the ability to. In the set comes the mains power supply, not actually the charger, in the case of the battery module retainer.
Power supply stupid to consider, his scheme is standard. transformer, diode bridge, capacitor filter is not a rectifier. At the output, you get 18 volts, for traditional 14 volt battery rechargeable.
Converting a standard Interskol charger for Li-ion-18650 with your own hands
save on shopping start saving here.
How to make a battery charger for a li-ion battery from a screwdriver
DO NOT IN NO WAY MAKE A KZ Here’s a link to a conventional converter Here’s a slightly different one
The charge control board takes up the area of a matchbox:
You, there is no heat sink on these assemblies, only a high power load resistor. That’s why such devices are often in a state of failure. The question arises: how to charge an electric screwdriver without a charger?
The solution is simple for a person who knows how to hold a soldering iron.
- The first requirement is the availability of a power supply. If the “native” unit is serviceable, it is enough to assemble a simple control circuit. In the case of failure of the entire set. you can use the power supply for a laptop. The required 18 volts at the output. The capacity of such source is enough for any set of batteries
- The second condition. the elementary skills of assembling electric circuits. Details are most accessible, you can unscrew from old household appliances, or buy at flea markets for next to nothing.
There is an 18 volt gold regulator on the input. Control circuit on KT817 transistor, gain provides powerful transistor KT818. Paths with their own hands for the garden and country houses: 50 photos how. It must be provided with a heat sink. Depending on the charging current, it can dissipate up to 10W, so a heatsink of 30-40cm² is needed.
It is the economy “on matches” that makes Chinese chargers so unreliable. A 1 Kohm resistor is needed to precisely set the charging current.
The 4.7 Ohm resistor in the output of the circuit should also dissipate enough heat. Power not less than 5 watts. Here is a selection of handmade battery charger circuits for car batteries.
The end of the charge is indicated by a LED and will go out.
The assembled circuit can be easily placed in the case of an original charger. It is not necessary to place the transistor heatsink, the main thing is to provide air circulation inside the case.
Economy is that the power supply from the laptop, is still used for its intended purpose.
For a domestic electric screwdriver it’s ok. Charged over night before working. enough to assemble the closet. The average charging time of a Chinese cordless drill. 3-5 hours.
Moving on to heavy weapons. Professional screwdrivers are used intensively and downtime because of low battery is inadmissible. Let’s omit the price question, any serious equipment is expensive. The more that the set usually has two batteries. While one is in operation, the other is on charge.
Battery charger for an electric screwdriver converted to lithium
dizzying hands 🙂 Watch out for traffic! Lots of pictures! And a lot of letters 🙂 If someone remembers, I’ve already converted the battery of my electric screwdriver to lithium quite a long time ago. But with normal charging for it all was dragging. And to charge it now you need not every few days but once a month 🙂 When I was not too lazy. I charged it from PSU with voltage and current limitation, when I was too lazy. I plugged it into an old native charger, which is not designed for lithium and gave out something about 18 volt and about three amps. Was hoping for a protection circuit board inside the battery. But the thought of a normal charger did not leave me. And even a power supply with a voltage and current regulator bought long ago:. PSU. www.aliexpress.com/item/Power-Supply-Module-AC-110v-220v-to-DC-24V-6A-AC-DC-Switching-Power-Supply-Board/32827334983.html. regulator. www.aliexpress.com/item/DC-DC-Step-Down-Adjustable-Constant-Voltage-Current-Power-Supply-Module-Drop-shipping/32787533675.html I chose a power reserve to give 20-24 volts to the AVR and limit it to 16.7 volts and up to 1 amp. Looking ahead. with PSU I was waiting a little bummer, but about this will be further in the review.
Except this, all fasteners under bolts (stainless steel) and screws, which also has long ago purchased on Ali. I bought several diameters from M1 to M3 🙂 Screws. www.aliexpress.com/item/500pcs-lot-DIN7985-Stainless-Steel-304-M2-Phillips-Pan-Round-Head-Machine-Screw-kit-m2x4-5/32765362652.html and the same seller has many other sizes of screws. www.aliexpress.com/item/400pcs-M2-Cross-pan-Head-Self-Tapping-Screws-Black-Oxide-Assortment-Kit-M2-4-5-6/32580525848.html and also other sizes are available from the same seller. Has come in handy more than once 🙂
This is what the native electric screwdriver charger looked like and the battery itself:
The battery was inserted upside down in it:
Inside the socket three contacts. two power and one for the thermal fuse inside the battery: (here the contacts are already out)
There is a transformer and some analog electronics in the charger:
The power supply and regulator did not fit into the original charger case, so I had to make a new case. At first the idea was to make a separate “cap” with contacts to put on the battery, and separately the charger itself. But then I thought that there is no gain, only unnecessary wires will be tangled underfoot. And decided to repeat the construction of the native charger. PSU with a regulator inside and a socket for the battery.
Lately, everything I’m going to make, I model first. Especially things that need to go with the already made. for example the battery of an electric screwdriver. And to have something to base the design on, I started with the model of the battery “foot”. It has a simple shape, just needed a caliper to get all the dimensions, the first printed model is perfectly compatible with the original: or so it seemed to me 🙂 After that I proceeded to model the socket, based on the already made model of the leg. I printed out the socket. the previously printed foot fits perfectly:
But the foot of the real battery somehow does not feel very cozy in the printed socket: I recheck all the dimensions. everything is correct, but the contacts do not get a little, a little loose and somehow sits crookedly. Finally I realized that the stem did not taper at all of its edges. The flat front edge goes straight, without any narrowing. Reprinted the stem and socket with that in mind and everything fell into place 🙂 Then I changed it a few more times and printed the socket, trying to get the size right. Several times it was my own negligence. in the model I had changed one size, the outer size, but after printing I looked at the inner size. And was surprised that somehow nothing changes 🙂
After trying two legs and four sockets I was completely satisfied with the result. I added the top surface to the socket, the ribs and the mount for the circuit board with pins: And went on to the next stage. modeling the body itself. I decided at once that the case will consist of upper and lower halves, only it was necessary to determine how to place the PSU and the regulator inside. For this I spent another half an evening and made their models. And began to virtually put them to each other and to the socket in different ways. In the end I decided on this layout:
When you understand the layout you get a better idea of the size of the hull, so you can start drawing the final shape. Started with the top lid. Nothing complicated. expand the top plane to the size of the hull, raise the walls, add posts to mount the stabilizer. On small vertical elements. the uprights, for 3D printing for example. it’s better to add ribs for reinforcement. And to the base of all vertical elements. especially thin ones, such as walls. it is useful to add chamfers to increase the area of the base, this will give additional strength. Didn’t forget about the cooling. on the top side I made two rows of narrow slots, just above the regulator heaters. I rounded the corners of the case and made it a little rounder near the socket, just for design’s sake 🙂 I added holes for two indicator LEDs. And made an edge around the perimeter. The bottom half will have a mating edge so that the halves fit into each other slightly. This is how it turned out: Trying on the regulator and the board with contacts: And the other side, with the inserted LEDs:
By the way, I also made the contact model separately 🙂 Later I also added a small cutout for the mains cord and fasteners to tighten the two halves of the housings:
With the lower half of the case even easier. I copied the outline of the upper half, pulled out the walls, added a stand for the PSU, mounting to tighten the halves, ventilation holes and trailing edge: Installing the PSU: And you can see how it all feels in height: feels great 🙂
A cordless electric screwdriver has a lot of advantages over a mains-type device. It can be used even where there is no electricity, you can screw fasteners in hard-to-reach places, the movements of the wizard are not limited by the length of the wire or extension cord. In short, this option is often chosen for home works.
But a cordless electric screwdriver is limited in operating time by the capacity and quality of the battery installed. It can be used as long as it does not run out. And if the battery failed and stopped holding a charge or even charging, then the electric screwdriver itself will not work. Either the battery needs to be replaced or it must be converted to a networked version. In some cases it is not possible to replace the battery at all. And a new one costs almost as much as a new device. Of course, in such a case, most people will decide to buy a fresh model of electric screwdriver.
A new battery for an electric screwdriver sometimes costs as much as a new tool
Just a side note! The average lifespan of a battery in an electric screwdriver is about 3 years. After that it must be replaced.
But, as practice shows, in some cases, it is easier and cheaper to convert the cordless electric screwdriver to work from 220 V. You will give the tool a new life and save money. The only limitation that such an upgraded electric screwdriver will have is the need to plug it in before use. But there is an opportunity not to stop work at the time of recharging the battery.
Charger for lithium batteries 18650 with their own hands
Batteries play an important role in any machine that is not powered. Rechargeable batteries are quite expensive because you need to buy a battery charger along with them. Batteries use different combinations of conductive materials and electrolytes. lead-acid, nickel-cadmium (NiCd), nickel-metal hydride (NiMH), lithium-ion (Li-ion), lithium-ion polymer (Li-Po).
I use lithium-ion batteries in my projects, so I decided to make a battery charger for lithium 18650 batteries with my own hands, rather than buy expensive, so here we go.
Reworking an electric screwdriver charger into a lead battery charger. Dexter 45VT
Two chargers have been lying around for two years. One is a charger from a Makita DC1414 electric screwdriver, which I will describe later. The second charger is from a Dexter electric screwdriver. Electric screwdriver Dexter itself is broken (by the way, perhaps someone has an extra button, I can not find the button. We don’t sell them here), but the charger from it is capable of delivering at 12.3V 45W of power, which at 14.4V is about 3A. The idea should not be a bad charger for charging lead car batteries.
Without long thinking I took the charger apart, took out the board and found that the power supply is based on a very famous PWM 3842 or 3845. The battery charger is assembled as follows. In the power supply is a shunt that limits the current in the primary winding, thereby limiting the maximum output power. I stabilized output voltages with optocouplers, connected through Tl431 with a 2.5V divider, and additional control from the CPU to the 1st leg of TL431, through a 1n4148 diode and a 10k ohm resistor. Power to the rechargeable LI-ION batteries was passed through a protection relay with a transistor stage controlled by the processor. On the minus line current shunt, to control the current of the batteries being charged. It has an Opu LM324, to amplify the shunt voltage, to amplify the voltage from the thermistor, and then I did not understand. There was also a “brain”, i.e. a processor which controlled the battery voltages and controlled the whole circuit.
Having understood the principle of this charger, I decided to remake it. I took the simplest experimental way.
Removed relay and connected directly to the output. Turned on the charger and look at the output voltage, the battery is not installed. The voltage is within 6V. Now I disconnect the diode going to 1 leg of TL431 from the processor and measured the output voltage of 12,43V. This shows that all blockings are removed and the power supply is able to squeeze the maximum out. Using a variable resistor I try to set the voltage to 14,4V. The range of the variable resistor was not enough, then I replace the top SMD resistor of 36 kOhm with 43 kOhm and the voltage is as it should be.
Output voltage controlled by the processor in standby mode
Disconnected the processor. The net output of the charger is 12.4V
Charger under load 3,6A
The circuit of optocoupler and TL431
After thinking about this charger, came to the conclusion that no additional features in this charger is not needed, current regulator is not needed. This charger will be in the garage and from time to time will be charging a car battery at 55A. Is that to add to the circuit protection against polarity reversal and short circuit, such added to the charger to LM317 and make the indicator of the end of charging but that’s for next time
I connected the charger to different loads, charged the batteries. It’s just like clockwork. To lighten the load, I soldered all the wiring around the processor. I left only the control circuit optocoupler.
For network indication put a jumper on the LED. In addition loaded the output of power supply with two 1W 330 ohm resistors, that the power supply would not start without load.
Charger board after rebuild
The charger charges a 55A 12V car battery
Here is a video of how the charger works
Next time I will show you how I transformed the charger Makita DC1414 into the lead battery charger.If interested subscribe to the feed and add to the group workshop Eduard Orlov, left questions ask them in the Комментарии и мнения владельцев
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You don’t want to get into radio electronics routines? I recommend to pay attention to the offers of our Chinese friends. For a very reasonable price you can get pretty good quality chargers
Simple charger with LED charging indicator, green battery is charging, red battery is charged.
It has short circuit protection, protection against polarity reversal. Great for charging a Moto-Battery up to 20Ah, with a 9Ah battery in 7 hours and a 20Ah in 16 hours. The price for this charger is only 403 rubles, free delivery
The charger is suitable for the most diverse types of batteries 12-24V with a current of up to 10A and 12A peak current. Can charge Helium batteries and СА\СА. The technology is just like the previous one in the three steps. The charger is capable of both automatic and manual charging. On the panel has an LCD display that shows the voltage, charging current and the percentage of charging.
A good device if you need to charge all possible types of batteries of any capacity, up to 150Ah
, free delivery. As of this writing, the number of orders is 23, rated 4.7 out of 5. When ordering, be sure to specify the Euro plug
Converting a screwdriver battery to lithium batteries
Industry has long produced screwdrivers, and many people have older models with nickel-cadmium and nickel-metal hydride batteries. Converting your electric screwdriver to lithium will improve the performance of your machine without having to buy a new tool. Now many companies offer services to remake the batteries of an electric screwdriver, but you can also do it with your own hands.
Conversion to lithium 18650 batteries
Nickel cadmium batteries are low cost, can withstand many charging cycles, and are not afraid of low temperatures. But the capacity of the battery will decrease if you put it on charge without waiting for a complete discharge (memory effect).
Lithium-ion batteries have the following advantages:
- High capacity, which will provide a longer work time of the electric screwdriver;
- Smaller size and weight;
- Keeps a good charge when not in use.
But a lithium battery for an electric screwdriver cannot withstand a full discharge, so factory tools with such batteries are equipped with additional circuit boards that protect the battery from overheating, short circuits, overcharging to avoid explosion, full discharge.
These batteries can be simply ordered on aliexpress: Check the price on aliexpress
When the chip is inserted directly into the battery, the circuit is broken if the unused battery is separate from the tool.
Difficulties in conversion
Li-Ion batteries have objective disadvantages, such as poor performance at low temperatures.
In addition, when converting an electric screwdriver to lithium 18650 batteries, you may encounter a number of difficulties:
- The 18650 standard means that one battery cell has a diameter of 18 mm and a length of 65 mm. These dimensions are not the same as the nickel-cadmium or nickel-metal hydride cells previously installed in an electric screwdriver. Replacing the batteries will require placing them in the original battery case, plus installing a safety chip and connecting wires;
- The output voltage of lithium cells is 3.6 V, and the voltage of nickel-cadmium cells is 1.2 V. Let’s assume that the nominal voltage of the old battery is 12 V. This voltage cannot be provided by connecting Li-Ion cells in series. The voltage fluctuation limits during the charge and discharge cycles of an ion battery also change. Accordingly, converted batteries may not be compatible with an electric screwdriver;
- Ion batteries have a specific way of working. They can hardly withstand overcharge voltages over 4.2V and discharge voltages under 2.7V to the point of failure. Therefore, when modifying the battery, a protective plate must be installed in the electric screwdriver;
- It may not be possible to use the existing battery charger for an electric screwdriver with a Li-Ion battery. It will also need to be rebuilt or bought another.
Important! If the drill or electric screwdriver is cheap and not of very high quality, it is better not to engage in remodeling. It can come out more expensive than the cost of the tool itself.
Often 12 V batteries are used for screwdrivers. Factors to consider when choosing a Li-Ion battery for an electric screwdriver:
- Such tools use cells with high discharge current values;
- In many cases, the capacity of the cell is inversely related to the discharge current, so you can not choose it only by capacity. The main indicator is the current. The value of the operating current of an electric screwdriver can be seen in the passport of the tool. Usually it is from 15 to 30-40 A;
- It is not recommended when replacing the battery of an electric screwdriver for Li-Ion 18650 to use cells with different values of capacity;
- Sometimes it is advised to use a lithium battery from an old laptop computer. This is absolutely unacceptable. They are designed for a much lower discharge current and have unsuitable specifications;
- The number of cells is based on the approximate ratio of 1 Li-Ion for 3 Ni-Cd. For a 12 volt battery you will need 3 new batteries to replace the 10 old ones. The voltage level will be slightly reduced, but if you install 4 cells, the increased voltage will shorten the life of the motor.
Important! All cells must be fully charged to equalize before reassembling.
Disassembly of the battery case
The case is often assembled with self-tapping screws, other variants are assembled with snaps or glue. The glued block is the most difficult to disassemble, you have to use a special hammer with a plastic head not to damage parts of the housing. Everything is removed from the inside. Only the contact plates or the entire terminal assembly can be reused to connect to the tool, the battery charger.
Joining of battery cells
The connection of Li-Ion batteries for a screwdriver is done in several ways:
- Using special cassettes. The method is fast, but the contacts have a high transient resistance and can quickly be destroyed by relatively high currents;
- Soldering. A method suitable for those who know how to solder, because it is necessary to have certain skills. Soldering must be done quickly, because the solder cools down quickly and prolonged heating can damage the battery;
- Spot welding. Is the preferred method. Not everybody has a welding machine, such services can be provided by specialists.
Important! The cells must be connected in series, then the voltage of the batteries add up and the capacity does not change.
In the second step, the wires are soldered to the contacts of the assembled battery and the protective circuit board according to the wiring diagram. To the contacts of the battery itself for the power circuits are soldered wires with a cross-sectional area of 1.5 mm². For other circuits you can use thinner wires, 0.75 mm²;
Then a piece of shrink tubing is put on the battery, but this is not necessary. You can also put a heat shrink on the protective chip to isolate it from the battery, otherwise the sharp protrusions of the soldering can damage the cell shell and provoke a short circuit.
Assembling the battery
Further replacement of the battery consists of the following steps:
How to remake with your own hands
Before you convert an electric screwdriver, you need to clearly determine how much power and what voltage the tool needs to work. This will have to be the starting point.
It is important to choose a power supply that is not too big and relatively light, so as not to make the work with the electric screwdriver very inconvenient. If you plan to install the unit directly into the electric screwdriver, it is important to keep the dimensions.
Then the body of the tool is opened. The two halves of the case can be fastened with screws or with glue. A knife can be very helpful during disassembly.
After opening the case, the power supply unit or wire is inserted inside, the contacts of which should be soldered to the charger. Soldering should be as efficient as possible, using special solutions.
The other end of the wire should be for mains feeding. So there should be a plug. It is recommended to make a hole in the case beforehand, through which the cable will pass.
There are several ways to make a homemade power supply. In any case, you will get a complete tool, which can be used to perform the work after connecting it to the mains. It is desirable to prepare a diagram in advance, which will help not to make a mistake when creating the block.
Remaking a Chinese-made power supply
Perfect to create a power supply for an electric screwdriver 12 volts with their own hands will approach an ordinary Chinese power supply with an output voltage of 24 V and a current of 9 A. But since the tools use a lower voltage, you need to lower it first.
To achieve the goal you need to replace the original resistor R10 with a tuning resistor, which will help you to achieve the desired voltage. This is done in several steps:
- the constant resistor is taken out;
- in its place is inserted a tunable resistor prepared in advance, which will have a resistance of 2300 ohms;
- for now the voltage is still 24V;
- With the adjustment of the resistor you must achieve the necessary voltage at the pins.
After all the manipulations it is necessary to check that the output voltage is the right value (12 V, 14 V, etc.).д.), and that the amperage is greater than 9A.
Modification of purchased blocks
You can also power from any other purchased power supplies. Process of alteration in this case will be almost the same, but in addition to the resistor, you may need to solder additional diodes. The most important thing is to achieve the necessary output parameters. And this can easily be done with a combination of components.
After the modification it is important to ensure a good air current to the box with the power supply. To do this, the holes are drilled. You should not allow the device to overheat.
Using a laptop charger
The use of a laptop charger is considered a great option. Such devices usually work with voltages from 12 to 19 V. This is quite enough to ensure the quality operation of an electric screwdriver. But do not neglect the output current. The closer it is to the required voltage, the better.
In this case, conversion of an electric screwdriver to power from the mains is reduced to the elementary soldering of wires from the charger to the board in the tool. It is desirable to insulate everything with tape or other similar materials. After that, the wire is led out and the tool can be used.
A power supply from a computer
You can make an electric screwdriver from the mains using an unnecessary power supply from a computer. There are many varieties of such devices, but almost all of them will fit an electric screwdriver. The necessary wires can be located by color by referring to the manufacturer’s website.
Power supplies from computers are characterized by durability, advanced overload protection and a host of other advantages. They may not be too handy because of their size, but a long wire will help solve this problem.
Procedure for connecting a computer power supply to a screwdriver:
- disassemble the unit;
- remove the power protection by disconnecting the green wire from the board;
- this wire must be connected to the black connector on the device;
- Separate all wires except the yellow and black;
- these two wires are soldered to the extension cable;
- The other end of the cable is connected directly to the screwdriver;
- All exposed contacts are insulated if possible.
Thus, from the computer device you get a power supply for a 14 volt electric screwdriver.
Power from a car battery charger
Power packs converted from car battery chargers are also quite common. The principle of alteration here is about the same as that of a computer power supply, but there are a few peculiarities.
The main feature is that usually such devices allow you to easily adjust the voltage and amperage. This greatly simplifies the procedure of use, and also makes it possible to apply the method to all screwdrivers.
Using car chargers comes down to a few simple steps:
- It is necessary to prepare special wires that will connect the power supply and electric screwdriver;
- the edges of the wire are stripped and inserted into the terminals on the tool (clamps can be used for better retention);
- When connecting it is necessary to observe the polarity, which is usually marked on the fasteners or the wires themselves;
- Now all connections are carefully strengthened and insulated.
After all these procedures, the user will get a functional electric screwdriver, which is able to work from the 220 volt mains.
All of the above methods are quite effective for creating a network tool from a cordless tool. But do not forget that in this case, the mobility of the electric screwdriver will be significantly reduced, which can affect the quality of work. But if the battery is out of order, and the work is urgently needed to continue. it is logical to connect an external power source.