Cordless electric screwdriver. quite a handy tool, but sometimes the advantages of such models turn into disadvantages. When the battery is finally discharged, it is necessary to buy a new battery. It can be very expensive, and in some cases it is simply impossible to find a suitable battery, for example, if the model has long been discontinued.
How to make a power supply for the electric screwdriver
Converting the screwdriver to mains operation is quite feasible. It requires some effort, but in the improved device does not need to reinstall the batteries.
If you convert a cordless electric screwdriver, the torque force in it will always remain the same
What kind of external units can be used. an old computer or a laptop charger?
As an external source, you can use available power supplies:
You can buy an old battery charger at the market. Nowadays, mostly pulse chargers are used, and older devices are often sold for lack of use. It is this charger with the possibility of manual adjustment of voltage and current is ideal for any electric screwdriver, regardless of its operating voltage. The whole conversion consists in connecting a low-voltage cord to the output contacts of the charger.
The power supply of the computer is purchased from older models, it must have a button to turn off. You won’t need one, but this is exactly the AT format you need. At the flea market you choose the block of 300-350 Watt, which will ensure reliable work of small and medium sized screwdrivers. All technical specifications are stated on the sticker on the housing. The unit has a cooling fan and overload protection. To remake a computer PSU with his own hands on an external for an electric screwdriver, perform simple operations:
- Disassemble the case;
- On the large square connector, find the green wire and any black wire;
- connect the two wires together, insulate them;
- On the other smaller connector, remove all wires, leaving the yellow and black;
- solder a low-voltage cable cord to them.
How to Convert Cordless Drill to Corded
To observe the polarity, you should know: the yellow wire. plus, black. minus. The computer power supply works with a tool with up to 14 volts.
Most laptop chargers have characteristics that allow them to be used as a power source for an electric screwdriver. Chargers with an output voltage of 12 to 19 volts will work. The only changes that need to be made are related to the output plug. It must be cut off, stripped the wires and soldered to them a cable of the right length.
Those with a background in electrical engineering can make a homemade power supply. Its circuitry is fairly simple and includes a step-down transformer, diode rectifier and two capacitors. All parts can be bought or taken from old radio equipment. Using a transformer from a tube TV set with 24-30V output would be nice. Rectifier diode bridge is necessary. Capacitors are used non-deficient, from old equipment: one at 0.1 uF and the other electrolytic at 4700 uF.
Warning! The design must be enclosed in a housing. To protect against short circuits it is mandatory to install fuses on the input and output.
How to convert a 12 or 18 volt cordless electric screwdriver into a cordless electric screwdriver with your own hands
The cordless electric screwdriver was designed primarily for mobility. It’s much more convenient to work with the tool without thinking about whether the wire is long enough, whether it’s not snagged, etc. д.
But without batteries, such a handy tool, such as an electric screwdriver, becomes a simple piece of iron, although it is fully functional. Battery life is about 3 years, and it is often impossible to find complete or similar batteries on sale. For example, the manufacturer has already stopped producing such a model, and other batteries are not suitable according to different parameters.
It is a pity to throw away a tool that you have paid money for, sometimes not a small sum, sometimes. Besides, the cost of batteries often is up to 80% of the price of an electric screwdriver, and it is more reasonable to buy a new tool. As a rule, the old tool is sent to a distant shelf and lies there uselessly. But there is a way to make it work again. to convert it to 220 volt power.
How to power an electric screwdriver, preserving its autonomy
There are situations when you have to work outdoors or indoors, where there is no electricity. In such situations, it is necessary to independently power the electric screwdriver to make it work. It can be done in several ways.
Replacing old components
often than not, people will not be able to use a battery tool because its battery has failed. The easiest way to solve this problem is to connect a new battery. It is recommended to use the same batteries that were in the electric screwdriver before.
Important! When replacing the battery, the polarity of the connection of the components must be observed. This prevents a short circuit.
Connecting to the car battery
Another way to quickly power the tool is to use the car battery. This is done as follows:
- Take three wires from the cigarette lighter and strip them of insulation by 3-4 cm.
- Connect the leads. These are connected to the battery terminals and the screwdriver.
- Tighten the connections with cable ties or insulate them with tape. It is necessary to wrap them in such a way as to hide all metal parts.
After that, you must check that the tool works.
Connecting to an external battery
If you need to use an electric screwdriver, you can connect it to an external battery. The battery from any unwanted UPS is ideal for this purpose. To connect the tool, do the following:
- Cut the electric screwdriver cable and strip the contacts on it.
- Connect the cord to the battery terminals.
- Test for reliable connections.
- Insulate the connections.
Use a LED driver
For a 12-volt tool, this driver is the easiest, but not the cheapest option. The only condition is that the power of the driver must be 10-15% more than the power of the tool. Otherwise, the power supply unit will go into protection already when you start the tool, and if it does start, it will not allow it to develop enough power to tighten the screw.
If, for example, a 12-volt screwdriver draws a current of 10 A, the power supply unit must be at least 130 W. You need a 400 watt power adapter for a 30-amp tool. Finding such a device is not a problem, of course, but its cost may exceed the cost of the screwdriver itself.
How to convert the screwdriver for this power supply? If the regular battery fails, we simply disassemble it, take out the batteries, and to the terminal of voltage supply to the tool solder wires connected to the output clamps of the driver, making sure that the polarity is correct. Connect the driver itself to the mains via the input terminals. and the redesign is over. we put the “battery” in the screwdriver and use it.
If the battery is good, you don’t have to destroy it, of course. Simply disassemble the screwdriver and connect the power strip to the power terminals of the tool itself. Of course, we take the socket outside and equip the power wire with the mating part of the connector. Connected the connector. working from the mains. We unplug the power supply, put the battery back in and you have a standalone tool.
Important! 10A is a big current, so wires cross-section should be big enough, and their length should be as short as possible (within the reasonable limits). Otherwise there will be a big voltage drop on the supply wires and the screwdriver will not develop the necessary power.
Assembling a mains power supply for an electric screwdriver in a battery case
It is convenient to convert the electric screwdriver into a network one, using the case from its battery. In this case, the internal stuffing is used:
Rebuilding a Chinese block for 24 V
Chinese-made PSU with an output voltage of 24 V (maximum current of 9 A) is not difficult to buy in places where radio components are sold. Most electric screwdrivers are designed to work with 12 or 18 V. For this reason it is necessary to lower the output voltage of the Chinese product to the right value. It is not difficult to do this, even with a superficial knowledge of radio and electrical engineering.
To modernize the power supply perform the following steps:
- Solder out with a soldering iron a constant resistor R10 with a resistance of 2320 Ohm, which is responsible for the output voltage;
- In its place solder adjustable resistor with a maximum resistance of 10 kOhm, setting this parameter to the value of 2300 ohms in advance, so that the built-in protection is not triggered when you turn on the made device in the network;
- Feed power to a remodeled unit;
- Turn the trimmer knob to set the desired output voltage, checking the value with a multimeter.
To connect the multimeter, simply touch the appropriate contacts on the output of the remodeled product with its feeler. In this case, the switch of the measuring device should be set to the DC voltage range. If the power tool to be modernized is designed to work from 12 V, then make sure that the current at this voltage level does not exceed the maximum value of 9 A. Otherwise, the created device will quickly fail due to overload.
Homemade plug-in power supplies
To power an electric screwdriver from the mains, you can also build a homemade power supply (PS). You will need a 60W electronic transformer, such as Taschibra or Feron. There is no need to modify them. The final schematic diagram of the power supply to be assembled is shown in the photo below. On it you can clearly see all the parts with their markings and basic parameters.
The T1 transformer will need to be made by yourself. To do this, proceed as follows:
- purchase a ferrite ring (NM2000) with dimensions of 28169 mm;
- With a file, chisel the corners on it;
- Wrap the ring with insulating tape.
All circuit parts are attached to the aluminum plate (3 mm thick or thicker), which will also serve as a conductor. Then assembled power supply unit is installed in the battery case.
Visual control of the device will be carried out by the LED lamp H1.
You can take ready-made parts also from energy-saving lamps and other devices. But then the circuit will be different, for example, as in the photo below. To solder them, you need some knowledge of radio engineering.
The above diagram corresponds to a power supply with a ballast lamp, the photo of which in the assembly is shown below. The light bulb also serves as a backlight.
Using readymade power supplies for modification
Inside the old battery case you can put any power supply designed for 220 V, the main thing that it has the right size and the required voltage at the output. You can buy a PSU with the right characteristics at radio markets or in amateur radio stores. To install the purchased power supply for an electric screwdriver instead of the battery do the following.
- Preliminary disassembly of the purchased product.
- Adapt it as needed, upgrading it to fit your needs. If necessary, the connection wires are lengthened, the transformer and the microcircuit are placed separately. For better cooling of the board, it is equipped with a radiator.
- After that, the parts are mounted in the housing from the battery pack, in which also make holes through which the air in circulation will dissipate heat.
All built-in parts inside the housing must be securely fastened.
Particular attention should be paid to the insulation of conductive parts between each other to prevent short circuits.
The degree of modernization of the purchased power supply depends on the compliance of its original parameters with the required values for the power tool. In order not to make a mistake with the size of the purchased power source, they take the case from under the batteries and try on the selected product according to it.
Features of an electric screwdriver
An electric screwdriver is a handheld device for working with various fasteners. It is used to unscrew or screw in screws, dowels, self-tapping screws and other fasteners, and in some cases allows you to drill holes as well. This power tool is operated electrically and has a special bit holder or chuck (for bits only) into which a drill bit or a bit with a shape to match the fastener (e.g. Phillips, hexagonal bits, etc.) can be inserted.д.).
- from the mains. respectively, has a mains cable and is spatially limited in use by the length of the wire (it can only be used if there is a socket or extension cord and cannot be used if the electricity is cut off);
- battery-powered. runs on a battery-battery, can be used where there are no outlets, but it can only be used until the battery runs out;
- from a compressor. the pneumatic version, which is activated by the supply of air.
- motor, which makes the spindle rotate;
- the spindle on which the bit chuck is mounted;
- chuck, which allows you to fix the right bit;
- gearbox that transmits the rotation from the motor to the spindle;
- speed regulator;
- pushbuttons for switching the direction of rotation (reverse);
- rechargeable battery. source of power (only cordless screwdrivers).
The product casing is made of plastic in most cases. this made the production of the device cheaper at one time. There are also metal variants. they are more reliable and durable than plastic ones, but they cost a lot more.
For your information! The very first example of an electric screwdriver appeared in 1982, and was unveiled at a trade fair in the German Democratic Republic.
You are now familiar with the construction of an electric screwdriver. This information will come in handy if you decide to convert your cordless version to a corded one, as you will still have to disassemble the device. It is not superfluous to know where and what this device has.
Cordless to corded drill conversion without torque loss
There are many ways to power an electric screwdriver
The mobility of the device
When converting cordless equipment to power from the mains one of its main distinctive properties is lost. mobility. Therefore, if you have decided to make a conversion of the screwdriver power supply, it is necessary to determine exactly what kind of device you want to use in the future.
There are two concepts on how to convert battery-type equipment into mains-type equipment:
- The power supply (PSU) will be external. This design involves a separate device. But do not let this scare you, even a heavy and large rectifier can simply be near the power outlet. You will still be limited by the length of the power cable either to the outlet or to the power pack. According to Ohm’s law, reducing the voltage for the same power increases the amperage. That is why the power cord of the device for 12-19 volts should have a larger cross section than the 220 volt power cord.
- The power supply is built into the battery case. In such a device mobility is almost completely preserved, only the length of the mains cable can limit the movement of the operator. One problem may arise when you need to install a high wattage transformer in the battery housing of the screwdriver. But the modern radio engineering industry allows us to solve this problem, there are a large number of compact rectifiers on the radio equipment markets.
Each of the methods finds supporters, as it has a certain set of characteristics.
Converting an electric screwdriver to mains power
A screwdriver is a tool designed for screwing screws and drilling holes of small diameter. There are mains-powered, with 220V and rechargeable, with two replaceable batteries.
If the battery in these devices fails, there are three options:
- battery replacement. expensive, in the machine of the budget class the price of the set approaching the cost of a new machine;
- Repair. not always possible, and in some cases its cost is comparable to the cost of new batteries;
- Conversion of a cordless screwdriver to a mains-powered one.
In this article it is told about how to implement power from the electric screwdriver 220v, or how to make a cordless screwdriver networked.