How to make an electric screwdriver from the mains

How to make Powerful Electric Screwdriver

Necessary materials and tools for converting a cordless electric screwdriver to a corded screwdriver

The easiest way to do this is to use your battery charger. In order to carry out the conversion of an electric screwdriver to power from the mains, you must first prepare the necessary tools and parts:

  • We need to prepare the charger.
  • A battery case will be needed.
  • Need a copper double-core wire that has a diameter of 2.5-4 mm. It must be 2 to 3 m long.
  • Soldering iron.
  • Solder.
  • Insulating tape.
  • Diagonal cutters.
  • Multimeter.
  • A mounting knife that will be used to cut or strip the wires.
make, electric, screwdriver, mains


Remember that all electrical safety rules must be followed when working.

What you need for conversion

For the work, in addition to the electric screwdriver and power supply, you will need:

  • soldering iron;
  • Solder and flux;
  • multimeter;
  • Several wires with a cross section of 2.5 mm2 or more;
  • Insulating tape;
  • A sharp knife, chisel or scalpel.

You also need a minimum of knowledge in electronics, know how to use a tester and soldering iron.

The cable to connect the electric screwdriver to the mains

Wire can be thinner than 2.5 mm 2. if the tool is not used for extended periods of time. Otherwise, overheating of the cable, melting of contacts and subsequent short circuit are possible. The length of the wire affects the voltage drop, so do not

Use a wire longer than 3-4 meters is not recommended because of the voltage drop. The tool’s maneuverability and portability will be increased by the use of an extension cord. Do not twist a pair or more pieces of wire, especially those with different cross sections and made from different materials. This approach lowers the current parameters. at the twisting points, the resistance increases.

Power supply capacity for an electric screwdriver

Calculating the power consumption of an electric motor for an electric screwdriver has been known since high school. Multiply the current drawn by the voltage applied to the motor. For example, if the battery is labeled: 3 Ah and 18 V, you need a power supply that delivers a minimum current with the appropriate parameters. These values are valid for no-load operation.

For normal operation of the motor under load, a reserve of about 30 percent is required. Otherwise, there is not enough power to screw fasteners, and if there is a large reserve, the power element can break down.

The parameters of the battery are indicated on its case

Also please note! The current strength of household tools reaches 3-4 A, professional. can exceed a dozen Amperes. Voltage is 12, 14 or 18 V. All parameters are indicated on the case of the battery, in the instruction manual, data sheet or on the official website of the manufacturer and vary for different models.

How to make a cordless electric screwdriver from 220 V with your own hands

Converting the cordless screwdriver for 220 V mains supply allows you to work with the electric tool almost continuously. You won’t have to charge the batteries, change them, service them or buy new ones to replace them. Disadvantage. the device will be tied to a socket, you will often have to carry an extension cord.

How to make a power supply for an electric screwdriver with his hands and 12 V, 14 V, 18 V and 220 V

PSU consists of a power transformer, capacitor and rectifier. The represented power supply circuit of an electric screwdriver from the network with a nominal voltage of 220 V is designed for 12 volt devices.

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Example circuit

The transformers in a typical circuit are chosen with a power of 300 Watts or more. The second winding has a voltage that varies around 20-24V. The current should not be less than 15A. Diode bridges also depend on the voltage of the current II winding. The capacitor, which is on the output, must have a capacity of at least 470 uF, and the incoming voltage of at least 25V. The elements are mounted in a circuit board, firmly mounted in a properly sized housing. After that, the electric screwdriver is connected to the electric network of 220 V and checked with a multimeter for compliance with all parameters.

Options for making a power supply

You can use the standard battery charger for this purpose. Here’s how to turn a cordless electric screwdriver into a mains screwdriver: you must do the following:

  • It is necessary to remove the cover from the case of the battery charger.
  • Make a hole in it for the connecting two-wire wire.
  • On the board, you can see the terminals, to which the battery used to be connected for recharging. To them it is necessary to connect the cores of the prepared wire to convert the electric screwdriver for such work. Take into account polarity of terminals. To determine it, you need to look at the inscriptions on the board or on the body of the device.
  • It is necessary to open the battery case of an electric screwdriver and remove all the galvanic elements from it.
  • Make holes in it for the wire.
  • Wires that were soldered to the terminals of the charger are connected with observance of polarity to the output contacts of the battery.
  • After the housing is assembled, the tool can be used.

Although it is recommended to connect the power with the polarity in mind, nevertheless, if you connect the contacts in a different order, it will mean that this is how you can convert a cordless electric screwdriver to a mains. the direction of rotation will be reversed. Most screwdrivers have the ability to switch it, allowing you to not depend on observing polarity when switching.

DIY Powerful Electric screwdriver | N20 Gear Motor

Laboratory PSU

Using a laptop charger

A laptop charger can be substituted for this tool, making only minor modifications. It receives AC voltage from the 220v mains at the input and outputs 12v DC current at the output.

However, it will still be necessary to rework the wires:

  • The plug used for a laptop will not work with an electric screwdriver. So it will be necessary to cut the wire coming out of the charger, and strip it.
  • If necessary, you will need to attach a cable of the right length.
  • The body of the tool needs to be disassembled.
  • Connect the cable to the terminals that supply power to the electric screwdriver. A hole must be made in the body of the tool.
  • The tool, once assembled, will be ready for use.

Important. Once the redesign is complete, you will need to connect the power supply to the mains and make sure the tool is in working order.

Laptop charger power diagram

Computer power supply as a base

You can make the power supply of the tool so that it uses the power supply of the computer. Here’s how else to make a power supply for an electric screwdriver: you need to do the following to remake it this way:

  • It is necessary to find or purchase a power supply with at least 300 watts of power.
  • The casing of the electric screwdriver must be disassembled and find the place to connect the wires for the motor power supply. The wires of the wire, which was prepared beforehand, are connected to them.
  • In the case, you need to make a hole for the output wires.
  • To connect to the power supply you need special connectors. One is soldered to the wires coming from the electric screwdriver, the other is already installed on the wire that is connected to the computer power supply. This is to power the electric screwdriver from the mains
  • Now it’s time to assemble the body of the electric screwdriver.

Now it remains to check how the tool works. To do this, plug the power supply into a 220V socket, and plug in the electric screwdriver.

Power from the car charger

It is possible to remake this tool to get power from a car battery. In this case, the autonomy increases, because you can use an electric screwdriver in the vicinity of the car.

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In order to convert the volt voltage to 220V you need:

  • Disassemble the housing of the tool. In doing so, you can see the contacts to which the power must be connected.
  • You need to prepare the wires that are used to charge car batteries. They have crocodile clips on them. The other ends have to be carefully deburred with a knife.
  • The wires are attached to the contacts for powering the electric screwdriver. They can be attached with cable ties or soldered. The last option is more reliable.
  • A hole must be made in the tool body for the wires.
  • Now the screwdriver housing has to be assembled.

To do the job, you will need to connect the wires with clamps to the car battery.

Power from the battery charger

How to make a power supply for the electric screwdriver

Homemade power supply

Making a power supply for an electric screwdriver with your own hands according to one of the diagrams, it must be inserted into the housing and connected by wires to the motor of the tool.

The power block is built into the battery

One option for modifying an electric screwdriver in the mains is that the power supply unit, which converts alternating current of 220v to direct 12v, can be placed directly in the battery case. To do this, you need to do the following steps:

  • The battery housing must be disassembled.
  • Remove the battery contents.
  • It is necessary to purchase a power supply beforehand, which has the characteristics necessary for the operation of an electric screwdriver.
  • Remove the motherboard from the purchased device and install it in the housing, where the battery of the electric screwdriver used to be.
  • Connect the output wires to the battery terminals.
  • For the input wires that will supply 220V voltage, it is necessary to make a hole in the housing.
  • Now the electric screwdriver must be assembled.

After the changes made, this tool can be used wherever there are electrical outlets.

Mains unit

Tips for use

Experts change screwdrivers, which easily cope with the established task, advise beginners to follow certain rules:

  • The mains electric screwdriver is able to function for several hours in a row, so give it five-minute breaks to protect it from overloading.
  • The wire should be attached at the elbow to prevent interference during operation.
  • Clean dust and dirt from the power supply unit at regular intervals.
  • Battery (new) is equipped with a ground connection.
  • It is not recommended to use a large number of extension cords.
  • Do not use the electric screwdriver for works at height (2 meters and higher).

Following these tips will help keep the tool in working order and extend its life.

Power supply and a bit of theory

Forums and search in Internet has prompted to me a standard destiny of the person who has decided to make a network screwdriver own hands from the battery one. long study of a theoretical part (in case of absence of a profile or general technical education, as it was with me), fast search for necessary pulse power supplies, understanding that to spend a couple thousand, and a choice in favor of purchase of the new screwdriver on replacement.

Indeed, let’s look at the theory. My PRORAB worked on a 12V battery, as evidenced by the mark on his motor. The power of the device is traditionally not specified by the manufacturer, because the figures are not very impressive against the background of wired analogues. It was necessary to figure out what parameters I would need for a power adapter for my screwdriver.

Measurement of motor’s power consumption on failure showed that we need about 100 VA to show the maximum performance. Approximately the same parameters advised the guru on the forums for 12 N/m of torque to take a pulsed 8−10А. The cost of such a unit comes out in 1000 r. plus wires, plug and other harness, which is also a lot.

The solution was pretty simple, if you do not have your own power supply, it will definitely be at work. And almost any company has an IT department, which most likely accompanies and fixes laptops of employees. That’s where I was headed. In the Electronics Recycle Bin we found a bunch of power supply units with different parameters. No 12V outputs were available, so I finally switched to a Toshiba laptop computer power supply with 15V/5A, or 75VA, which suited me fine. Sony 19V was also an interesting option, but I didn’t want to bother the Chinese one so much.

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Why convert a cordless electric screwdriver

Some people do not understand why a cordless electric screwdriver should be turned into a cordless screwdriver. It’s actually quite simple. The thing is, you can only use such a tool until its battery runs out. After a discharge the electric screwdriver would need to be recharged before it could be used again. Many people are not satisfied with it, so they decide to convert it to a cordless electric screwdriver.

It’s also often done when the battery fails and stops charging. Many people do not want to spend money on a new battery, and they decide to remake the tool to work on the mains.

Steps of Work

The first thing to remake the screwdriver to work from the mains it is necessary to solder electrical wires to the charging contacts of the device. The connection can be difficult. the wire is largely made of copper, and the charger contains brass terminals, which makes them difficult to solder. In this just help acid, which is excellent as a connecting element. For that you need to treat the brass charging terminals with it and solder the power cord to the contacts. Qualitatively done soldering will ensure trouble-free operation of the screwdriver for a long time.

Next, you need to remake the faulty battery. To do this, it is completely disassembled and take out all the insides, contrary to the manufacturer’s recommendations. Throwing the insides in the general trash is prohibited. The housing does not need to be discarded. a weight for the counterweight is placed in it.

The next step is to solder the cord pins to the battery terminals, which are located inside the case. During the work, it is important to observe the polarity, otherwise the screwdriver will screw in the opposite direction. This can be fixed with a simple switch.

After that, the cord is led into the battery on the outside of the housing, for which you must make a hole for the diameter of the wire. For reliable fixation of the wire in the housing, it is recommended to wrap it with insulating tape inside and outside, making a special lock that securely fixes the resulting design.

The last step will be the direct installation of the finished battery case into the screwdriver from the mains and its subsequent operation.

The unit from the PC

If the power supply itself is broken, there are several options for replacing it to operate the device. The easiest and most convenient option is to use an unnecessary power supply from a PC with a capacity of at least 250W.

On modern units to turn on is usually enough to short circuit the wires, the color of which may vary. You can find out the correct sequence on the internet or try out the selection method. The connector on the power supply for a 12-volt screwdriver is located in a four-pin connector: for black. minus, for yellow. plus. Such models are completed with a fan to be installed outside of the device. To respect the aesthetics and convenience when remaking a screwdriver from a computer power supply unit, the wires are hidden in the housing.

The car battery

Another interesting and practical option is how to make a screwdriver from 220v using a car battery charger. The only disadvantage of this solution is the rapid discharge of the car power supply, so you can not work long. This variant is perfect for those who have a failure of the car power supply unit, which happens quite often. Taking a few hours of time, an experienced craftsman will be able to remake the device to work from the auto battery, at which the screwdriver will work even more efficiently than from the original battery.

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