Converting an electric screwdriver to 220

Options for making power supplies for an 18-volt electric screwdriver

Mobile electric screwdriver on the battery is widely used in construction. One of the significant disadvantages of the model is the wear and tear of the battery, when worn out you have to buy a new electric screwdriver or look for a battery. An unconventional solution is offered by radio amateurs to make with their own hands a power supply for an electric screwdriver 18 V.

Materials and tools required

For most, the third option may seem complicated, because it is much easier to buy a new device and use it for a few more years. In fact, the old electric screwdriver will last even longer, but it is necessary to restore it. To do this is quite simple, and for this you will need the following tools and materials:

• Charger, which previously served an important role as a battery charger.
• Multicore Electric Cable.
• The battery from an electric screwdriver that is out of use.

Of the tools you will need a soldering iron, acid, solder and insulation tape.

All these details will allow you to convert an electric screwdriver to be able to connect it to 220 volts.

Why convert a cordless electric screwdriver

Some people don’t understand why they would make a cordless electric screwdriver into a corded model. In fact, everything is quite simple. The fact is that you can only use such a tool until its battery runs out of power. After discharging have to recharge the electric screwdriver and only then continue to use it. Many people are not satisfied with this and decide to convert the tool to a corded model.

It is also often done when the battery fails and stops charging. Many people don’t want to spend money on a new battery, so they decide to convert the tool to run on the mains.

How to convert cordless drill to corded, Black & Decker

• Disassemble the battery: remove all the screws hidden by the stickers. The batteries that are inside are interconnected. There are two wires that connect to them: a red wire and a black (-) wire.
• Cut the wires to the batteries. Cut it off from the cells, not from the battery terminals.
• Connect the wire to the open contacts of the charger by soldering, pre-treating the brass terminals with orthophosphoric acid. This will ensure a solid connection between the brass and copper cable.
• Insulate the connections.
• Place a weight in the housing where the batteries are located to act as a counterweight.
• Solder the battery leads inside the case to the free pins of the cable, observing polarity. If polarity is reversed, the tool will work, but rotate in the opposite direction.
• Connect the plug to the mains and check if it works.
• In addition, make a hole in the body of the electric screwdriver on the left side for the wire. To ensure a tight fit, make a “lock” of insulation tape.

How to make a cordless electric screwdriver network

The cordless electric screwdriver is a useful tool for household chores, construction, and assembling a wide variety of structures. Its main advantage is the ability to perform work autonomously, until the batteries are discharged. For a variety of reasons it may be necessary to convert an electric screwdriver for connection to 220 V. Such a modification is relatively easy to carry out independently in different ways, no special tools are needed for this. Depending on the chosen option, making changes will require different time and financial costs.

It is important to check the voltage and current of the charger

It is necessary to modify the battery block, for this purpose you need to disassemble it and take out the failed batteries from there.

• Take a laptop charger.
• Cut the connector and strip the wires of insulation.
• Take the bare wires and solder them. If you can’t do that, tape them down.
• Make a hole in the housing for the wire and assemble the assembly.

Use an external power supply from a computer

So you need an “AT” size power supply. You are likely to find it at home, but you can buy an old, working power supply at any radio market without any problem. Cost is not likely to be high. It is very important to remember that you need a PSU with 300-350W and a current of at least 16A on the 12V circuit.

A computer power supply type “AT” will power the screwdriver

• Unscrew the power supply enclosure. Under the case you will see the fan, the board and a lot of wires that go from the board to the connectors.
• It is required to remove the power protection. To do this, locate the green wire on the large square connector.
• Connect the green wire to any black wire from the same plug. For convenience you can cut it shorter and leave it inside the body. Alternatively you could use a jumper made from a small piece of wire.

Connector pins: yellow wire: 12V, red wire: 5V, black wire: ground

• Cut the unnecessary wires, leaving the yellow and black.
• Using a piece of wire as an extension cord, so that the power supply unit can be placed in a convenient place during operation, solder it to the yellow and black wires
• Attach the other end of the wire to the terminals of the empty battery compartment, as in the previous instruction.

Using the car battery

This is basically the same as using a laptop charger. Thanks to the current trend toward compact pulse chargers, linear analog units with manual controls can be purchased at the car market at a very attractive price. If the battery voltage changes smoothly, it will fit absolutely any screwdriver, and remodeling of such a tool is done as follows:

• To connect the screwdriver to the car battery, use inexpensive wires with a small cross section, car cigarette lighter wires will do.
• On all sides of each wire cut so-called “crocodiles”, on the free end stripped the wire of insulation by 2-3 cm.

Cut off the terminals and strip the wires
Bending the wires with a hook to connect them to the terminals

Taking a Chinese power supply board

So we are talking about a power supply with an output voltage of 24V and a maximum current of 9A. Wrenches are usually designed for 12V or 18V, so you must first lower the voltage to an acceptable level.

To change the output voltage, you need to make an improvement in the feedback circuit. The output voltage is controlled by the resistor under the R10 position. Its rating is 2320 ohms. Instead of this resistor let’s install a trimmer, so it will be possible to change the output voltage of the power supply to our needs, the nominal value of the trimmer resistor is 10 kOhm.

It is necessary to unsolder the permanent resistor
Solder a trimmer resistor into the board instead of a constant resistor
Adjust the output voltage and check the characteristics of the unit

How to remake a cordless screwdriver to work from 220 volt?

Methods of converting a cordless screwdriver to work from the mains vary in complexity, most often it is necessary to connect the electric screwdriver directly to the charger. Connecting the battery charger from a laptop requires little knowledge, to mount a computer power supply unit need to be friendly with a soldering iron, and to reconfigure the Chinese unit the master should be able to handle measuring tools. Take into account, the native power supply of an electric screwdriver is not intended as a rule, to connect the electric screwdriver directly, its capacity is designed only for charging the battery.

How to connect an electric screwdriver directly to a laptop charger

This method requires a minimum of technical knowledge. If there is a need to convert the screwdriver in the network, you can help an unnecessary charger from a laptop, since it has similar characteristics and easily found in any home. First you need to see what the output voltage of the charger is. Suitable chargers for 12-19V.

It is important to check the voltage and current of the charger

You need to refine the battery pack, for this you need to disassemble it and take out the defective batteries.

• Take a laptop charger.
• Cut off the plug and strip the wires of their insulation.
• Take the bare wires and solder them. If there is no such a possibility, you need to tape them down.
• Make a hole in the body for the wire and assemble the construction.

Use an external power supply from a computer

So, you need a “AT” format power supply. It is very likely that you will find it at home, but you can buy an old working power supply at any radio market. Its cost is unlikely to be high. It is very important to remember that a 300-350W power adapter is suitable, and the current in a 12 V circuit is at least 16 A.

The “AT” computer power supply will power the screwdriver

• Unscrew the case of the power supply. Under the case you will see the fan, the board and lots of wires going from the board to the connectors.
• The trigger guard must be removed. To do this you need to find the green wire on the big square connector.
• Connect the green wire to any black wire from the same connector. For convenience you can cut it shorter and leave it inside the case. Alternatively, you can use a jumper made from a small piece of wire.

Connector pins: yellow wire: 12V, red wire: 5V, black wire: ground

• Cut the unnecessary wires and leave the yellow and black one.
• Using a piece of wire as an extender, so that the power supply could be in a convenient place during work, we solder it to the yellow and black wires
• Attach the other end of the wire to the terminals of the empty battery compartment, as in the previous instruction.

Using a car battery

The principle is the same as using a laptop charger. Thanks to the current trend towards compact pulse chargers, linear analog units with manual controls are available at the car market at a very attractive price. If the voltage on the battery changes smoothly, then it will fit to absolutely any screwdriver, and modification of such a tool is as follows:

• To connect the screwdriver to the car battery, you should use inexpensive wires with a small cross section, car cigarette lighter wires will do.
• On all sides of each of the wires, cut off the so-called “crocodiles”, on the free end strip the wire from the insulation by 2-3 cm.

Cut off the clamps and strip the wires
Bend the wires with a hook to connect them to the terminals

Using a Chinese power supply board

So we are talking about a power supply unit with output voltage of 24V and a maximum current of 9A. Screwdrivers are usually designed for 12V or 18V, so you must first lower the voltage to an acceptable level.

To change the output voltage, you need to make an improvement in the feedback circuit. The resistor under position R10 is responsible for the output voltage. It’s rated at 2320 ohms. Instead of this resistor we will install the trimmer, so it is possible to change the output voltage of the power supply unit to our needs, the trimmer has a nominal value of 10 kOhm.

It is necessary to unsolder the DC resistor
Solder the trimmer resistor to the board instead of the DC resistor
Adjust the output voltage and check the characteristics of the unit

Rebuilding a power supply of a screwdriver to work from the mains

The screwdriver is indispensable for the job. Its application is effective not only in the household, but also in professional activities. Nowadays it is difficult to imagine carrying out repair and finishing works without this universal power tool. The screwdriver can work anywhere, regardless of power supply. But the rechargeable battery (battery) of power tools tends to discharge and the number of charge cycles is limited. On average, the battery lives about three years, and then you have to replace it, so craftsmen began to remake the power supply to the mains version.

Types of rechargeable cells

In these devices, elements of different types and voltages are used, each of which has its own advantages and disadvantages.

The most common are nickel-cadmium (Ni. Cd) 1.2V.

progressive nickel-metal hydride (Ni-MH) of 1.2V voltage.

Most advanced 3.6V lithium-ion (Li-Ion) batteries.

• no memory effect;
• very low self-discharge current;
• high specific capacitance, allowing to reduce the weight and size of the device;
• Many times more charge/discharge cycles than other types of batteries.