How to remake an electric screwdriver 12 volts to 220

How to Turn a Cordless Electric Screwdriver into a Network Screwdriver

There are two ways to make an adapter: use an old battery pack, because it already has a jack that will fit the screwdriver, or connect the wires directly to the handle.

Connecting the old battery pack

Connect the old unit as follows:

First you need to disassemble the battery pack by removing the screws as shown in the figure.

Take out the old nickel cadmium batteries.

Next, separate them from the connector pins.

Connecting the wires directly

Connecting the wires directly to the screwdriver is done as follows:

To connect the wires directly, you must first disassemble the screwdriver, that is, unscrew the screws that fasten the two halves of the body.

Consider the connections, find the plus and minus, remember the polarity of the connection. For convenience, it was decided to remove the bottom wide part of the handle.

Next, you need to connect the wires, this can be done with a soldering iron or good old duct tape.

And the final touch is to wrap the wires at the exit of the handle for extra fixation and insulation.

Wanted to know how to make a screwdriver directly from the charger?

Congratulations! Now that you have learned how to convert a screwdriver to a cordless electric screwdriver, you will be able to put this knowledge into practice

And whether your screwdriver is charged or not. You won’t have to wonder how long the battery will last

Instructions for rewiring

Let’s take a closer look, step by step, at how you can convert a cordless electric screwdriver to a corded screwdriver.

Disassemble the battery

In order to convert the tool to a corded tool, receiving voltage from the native charger or from a computer power supply unit, you need to perform simple steps.

First disassemble the old battery pack. Remove fixing screws. It is important that all terminals are retained.

Pull out the innards

Remove the batteries and carefully loosen the terminals. Then a wire with a cross section that can handle the operating current is soldered to these terminals. The wire should have a cross section of at least 2.5 mm² and be as long as you need for comfortable operation of the electric screwdriver. Remember which color wire we solder the minus and plus terminals to.

Connect the wires

Dismantle the computer power supply housing. Remove the board and solder the wires on the power cable. To the wires coming out of the power supply, instead of the yellow and black wires, solder wires with terminals from the battery. The black wire is the minus contact, and the yellow wire is the plus contact.

You can increase the power output of the power supply by connecting the black wire to the black wire and the yellow wire to the yellow wire. This will improve the operation of the electric screwdriver, because the losses will be reduced.

To start the computer power supply, you need to short the green wire from the 20 pin connector to the black wire. This can be done directly on the PSU board. For convenience you can connect a switch to the green and free black wire.

For convenience you can solder a special connector to the wires, allowing them to disconnect. The polarity must be correct or you will damage the electric screwdriver. To do this, the connector must be keyed (a special tab on the housing that prevents it from being connected incorrectly).

Put everything back together and connect the electric screwdriver to the 220V mains

You need to assemble a “modified” battery. We insert the terminals with wires into it and lead them out through the drilled hole. A 10,000 uF capacitor, 16 V or 25 V, should be placed inside the former battery case and connected in parallel to the terminals. Select a capacitor with a voltage of 1.5 or 2 times the rated voltage of the tool.

Such a capacitor will compensate for high starting current. If it is not put, the probability of power supply tripping by built-in protection will considerably increase. It is also recommended to put a weight inside the tool to balance it out. This will reduce the strain on the hand during operation.

Putting the computer power supply together and connecting the electric screwdriver to the 220 V mains. If the test reveals that the tool lacks power, you can replace the low-voltage power wire.

Is it really worth redoing??

Without batteries, the screwdriver becomes a piece of metal. When batteries stop holding a charge, you have to look for new batteries. First of all, it is expensive. the price for the batteries is up to 80% of the cost of a screwdriver, so it is more effective to buy a new tool. Secondly, batteries are not always available, for example, if the model is discontinued. Third, the diligent owner strives to use every opportunity to save money.

Converting a cordless screwdriver to run on mains power is a good way out. What it gives:

  • Tool gets new life.
  • No more need for batteries that require a charge.
  • Tool’s torque is not related to battery charge.

The disadvantage of this remodel is that it depends on the outlet and the length of the power cord.

Attention! You cannot use a converted cordless screwdriver if it is higher than two meters.

Power supply for an electric screwdriver with his own hands

In order to convert a cordless electric screwdriver into a mains one, you must first make a step-down transformer. It is made on the basis of the one used in TVs of older models. When powering an electric screwdriver from an electronic transformer, the latter must be rated at 160W. In order to prepare one, which is necessary for a screwdriver, you need to do the following:

  • The transformer should be taken apart.
  • The secondary winding must be removed completely.
  • It is necessary to wind ten turns.
  • Now the transformer is ready, all that is left is to assemble it.
  • The following measurements must be made. Now connect it to the mains and measure the voltage obtained on the secondary winding. Now divide the number of windings, which in this case is ten, by the presently measured voltage. Multiply the obtained value by the required voltage for the tool and get the number of necessary turns.
  • Now disconnecting the transformer from the mains, it is disassembled again and wind up the required number of turns. Then it must be assembled.

For winding a wire, the cross section of which is equal to 1 sq. mm.

After the current has passed through the transformer, an alternating voltage will be at the output. The scheme of the power supply for an electric screwdriver provides that in order to get the DC from it, you need to make a diode bridge. It is made using diodes on heat sinks designed for 20V and 10A.

Put the transducer made this way into the case. At its output will be obtained the voltage that is necessary for the operation of the screwdriver. At the input will be the mains voltage of 220 V.

Connect the wires coming from the PSU to the contacts, through which the tool is powered.

Such a power supply for an electric screwdriver from the mains is usually assembled in the case, where previously there was a battery cell.

The construction of the battery of an electric screwdriver

Converting an electric screwdriver to lithium 18650 batteries

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The design of the battery is brand-independent. In all devices, the design of batteries is similar and differs in appearance, housing and contacts.

Battery design

There are several cells in the case, connected in series. Their number depends on the voltage of each cell and the battery as a whole. If you use the most common, nickel-cadmium cells with a voltage of 1.2 volts, to supply the device rated 12V needs 10 pcs. Battery capacity is specified in ampere hours.

Interesting. If connected in series the output voltage increases, but the capacity does not change and is equal to the capacity of individual cells.

Household or professional

As you know, professional screwdrivers are more expensive, but this is no accident. They are made with a large margin of safety, for which higher quality and more expensive materials are used. They also have more power, which makes it possible to screw in longer screws and/or work on tougher materials.

The difference between a professional and domestic electric screwdriver in the resource

To decide whether you need a domestic or professional electric screwdriver, assess the amount of work you will need to perform. If you start construction or major repairs, you probably need a professional or semi-professional model. If you need a tool from time to time. something to unscrew/screw from time to time, a household tool is more than enough. With this kind of work, the resource of a pro tool will simply not be in demand. So it is not very difficult to choose an electric screwdriver by this criterion.

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Power supply options

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

  • You need to remove the cover from the body of the charger.
  • It is necessary to make a hole in it for a double wire to be connected.
  • 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. Note the polarity of the terminals. To determine it, look at the inscriptions on the board or on the body of the device.
  • It is necessary to open the battery case of the electric screwdriver and remove all the galvanic elements from it.
  • In it make holes for the wire.
  • Wires that have been soldered to the terminals of the charger are connected with observance of polarity to the output contacts of the battery.
  • After the case is assembled, the tool can be used.

Although it is recommended to connect the power with the polarity, however, 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 network. the direction of rotation will be reversed. Most screwdrivers have the ability to switch it, allowing you to not depend on the polarity of the switch.

Laboratory PSU

Using a laptop charger

Notebook charger can be substituted for this tool with only minor changes. It takes AC voltage from the 220v mains at the input, and gives 12v DC current at the output.

However, it will still be necessary to make modifications to the wires:

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

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

Laptop power supply circuit

Computer power supply as a base

It is possible to 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: to remake in this way you need to do the following:

  • It is necessary to find or purchase a power supply, the power of which will be not less than 300 W.
  • The body of the electric screwdriver must be disassembled and the place of connection of the wires for the motor power supply must be found. The wires prepared in advance are connected to them.
  • In the case it is necessary to make a hole for the output wires.
  • Special connectors are required for connecting to the power supply. 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 we have to assemble the electric screwdriver body.

Now it remains to check how the tool works. To do this, you need to plug the power supply into a 220v outlet, and plug the electric screwdriver into it.

Power from the car charger

It is possible to remake this tool so that it can be powered by a car battery. In this case, the autonomy is increased, because it will be possible to use the electric screwdriver in close proximity to the car.

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

  • Take apart the housing of the tool. In this case you can see the pins to which the power should be connected.
  • It is necessary to prepare the wires that are used to charge car batteries. They have crocodile clips on them. The other ends must be carefully deburred with a knife.
  • The wires are attached to the contacts for powering an electric screwdriver. They can be attached with cable ties or soldered. The latter option will be more reliable.
  • You need to make a hole in the body of the tool for the wires.
  • Now the screwdriver housing must be assembled.

To do the work it will be necessary to connect the wires with clamps to the car battery.

Power from the charger

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 with the wires to the motor tool.

The mains unit built into the battery

One option for modifying an electric screwdriver in the network 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:

  • It is necessary to disassemble the battery housing.
  • The contents are taken out of it.
  • The power supply must be purchased beforehand, which has the necessary characteristics for the electric screwdriver to work.
  • From a purchased device you need to remove the motherboard and install it in the case, where the battery of the screwdriver was before.
  • The output wires are connected to the battery terminals.
  • For the input wires, which will supply voltage of 220v, it is necessary to make a hole in the housing.
  • Now the electric screwdriver must be assembled.

After the modifications have been made, the tool can be used wherever there are electrical outlets.

The device device

The screwdriver consists of several basic elements:

  • Cylindrical electric motor powered by current. There are permanent magnets inside the body, which make it possible to build up sufficient torque. They are also handy when repairs are needed. The motor shaft contains a planetary gear.
  • Torque limiter. Needed to limit gain when working with a screwdriver. Transmits torque through inner-spring pivots.
  • Planetary reduction gear. Named after the solar system, which is similar in assembly. Located in a separate case and consists of several gears and other parts. Acts as a force on the load regulator. Operates harder in drill mode.
  • Speed regulator with reversing function. Is actuated by reversing the polarity of the connection.
  • Battery of the device. Provides several individual power cells in a single housing. Voltages range from 9 to 25V in different devices.

Exploded view of the device Source stroy-podskazka.When the battery pack malfunctions, replacement or repair options are available. It is usually expensive to replace such batteries, as in a cheap device, the replacement will be about equal to the full cost of the screwdriver. Repair is not always possible, in addition, as in the first option, its cost will be close to the full price of the device. But there is also a third option, such as to convert the screwdriver to work on the mains, which allows you to use the tool further without much cost and effort.

Powering the screwdriver by itself

Work with a hand-held tool can also be done in a building where there is no electricity. In such cases, the device is connected to the car battery or any other power device suitable for the operation of the screwdriver.

To connect the car battery, you must take a wire with crocodile clips, bare one end and solder directly to the contacts of the electric motor of the tool. The second end is clipped on to the battery terminals, observing the polarity.

The connection principle of a portable battery is similar to a car battery. Only the ends of the wires are fitted with copper clamping terminals suitable for attachment.

An electric tool lasts much longer than a battery tool. So don’t throw away your screwdriver if the batteries are used up. The handy man can convert his power tool to mains power, thereby prolonging its life.

The steps of the job

The first thing to convert a screwdriver to work from the mains is to solder the electrical wire to the charging terminals of the appliance. The connection can be tricky. the wire is largely made of copper, and the charger contains brass terminals, which makes them difficult to solder. Acid, which is excellent as a connecting element, is just the thing to do. To do this, you need to treat the brass charging terminals with it and solder the power cord to the contacts. Qualitatively done soldering will ensure the smooth 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. It is forbidden to throw the insides into the general trash garbage can. There is no need to throw out the case, a weight for counterweight is placed inside it.

The next step is to solder the contacts of the cord to the battery terminals, which are placed inside the battery housing. During the work, it is important to observe the polarity, otherwise the screwdriver will screw in the opposite direction. This is corrected by the usual switch.

After that, the cord is led into the battery from the outside of the case, and for this purpose it is necessary to make a hole for the diameter of the wire. To reliably secure the wire in the case, it is recommended to wrap it with insulating tape inside and outside, making a special lock, which will reliably secure the resulting structure.

The final step is to directly install the finished battery case into the screwdriver from the mains and then operate it.

The unit from a 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. to use unnecessary power supply from the PC with a capacity of at least 250 watts.

On modern units, a shorting of the wires, the color of which can vary, is usually enough to turn on. You can find out the correct order on the Internet or try to guess it by fitting. The connector on the power supply for a 12 V screwdriver is a four-pin connector: minus for black, plus for yellow. Such models are equipped with a fan, which must be installed outside the device. To respect the aesthetics and convenience when remaking a screwdriver from a computer power supply, the wires are hidden in the case.

The car battery

Another interesting and practical option. this is how to make a screwdriver from 220v with a car battery charger. The only disadvantage of this solution is the rapid discharge of the automotive power supply, so you can’t work for long. This option is ideal for those who have had a power supply unit breakdown, which happens quite often. By taking a few hours of time, an experienced craftsman will be able to convert the device to run on an auto battery, in which the screwdriver will work even more efficiently than the original battery.

Safety Precautions

After converting the device to mains power, it is necessary to follow the safety and operating rules:

  • Take a break every 30 minutes to extend the life of your appliance and avoid malfunctions.
  • It is not recommended to work more than two meters high.
  • It is important to clean the power supply of the device from dust periodically.
  • Check the condition of the power cord. It must not be compressed or exposed to moisture and other negative factors. Ignoring this rule can cause the device to short circuit.

Following these simple guidelines will allow an old screwdriver to last longer than a new one, while still retaining its power and ease of use.

Power supply options

Any electric screwdriver requires much less voltage than a conventional outlet. Therefore, a special converter is needed for feeding, the output of which will produce the necessary voltages. All power supplies fall into two broad groups: switching and transformer. Let’s look at each of them separately.

Impulse

Switching systems work by first rectifying the voltage and then converting it into a special pulse signal. It is important to achieve a stable voltage. A transformer winding or resistors can help.

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Switching power supplies are quite effective and can be used in different conditions. At the same time they have a high level of protection against short circuits and similar effects. But in terms of wattage, pulsed systems clearly have less power than a transformer power supply. In addition, such blocks are very capricious to the input voltage. If it is lower than the set, the element may simply not work.

Transformer

common power supplies that have been proven to be reliable and efficient in many applications. It consists of a step-down transformer and a rectifier, through which the reduced voltage is fed. Rectifiers can be different, depending on the number of diodes used.

Such elements are simple to make, cheap and reliable. That’s why they are often preferred. They provide a stable voltage without interference with high maximum power. But there are a few drawbacks. The main disadvantage is cumbersome, with a much lower efficiency than pulse sources. This fact requires to choose a power supply for an electric screwdriver with more power than necessary for the tool. Since part of the power will go to side processes.

Materials and tools needed

Materials and tools when remaking an electric screwdriver depend entirely on the type of tool and the type of power source, as well as its features. But to summarize, there are a few basic tools:

  • screwdriver;
  • pliers;
  • knife;
  • insulating materials;
  • cable for power supply;
  • soldering iron and soldering materials;
  • some kind of case for the future power supply.

Powering an electric screwdriver from a 220V

I have finally begun to implement my long-standing idea, namely, to provide power for an electric screwdriver from a 220 volt. Undoubtedly some of you also have a screwdriver, with a worn out, unusable battery that no longer takes a charge. In my location I had two.

The first (black) has a working voltage of 18 volts. It was the one I originally wanted to power from the mains, t.к. Easy to hold and quite powerful. But there is no button. Maybe in the future I’ll cut the handle and turn it into a drill bit. The second one was designed for 12 volt. Has been around for a long time. Of course, you can buy new batteries or replace batteries with new ones. But all the same I want to have always a ready tool at hand, especially when it is not always convenient to use an electric drill.к. it’s heavy. A power transformer will help us to realize this idea.

A TC-250-36 step-down transformer was used. “250”. This is its rated power, and the number 36 means that the output will be 36 volts. It has an O-shaped magnetic core. Its windings are arranged so that half of the primary is wound on the left side and the other half on the right. Similarly wound and the secondary winding, which is located on top of the primary. It is not difficult to distinguish the windings from each other in a step-down transformer, t.к. The secondary was made of a thicker wire, and the one with the line voltage was made of a thinner wire. That’s because it carries a smaller current.

The windings have a symmetrical arrangement and the two 18 volt halves are connected with a wire (you can see the connection place in the picture below). I’m going to use one half.

But before you rewind the transformer you have to measure. I urge you to be careful when working with current, not to touch live parts, and always check if the meter has the correct measurement limit.

On the right side you measure the voltage at half of the secondary. As you can see, the voltage is slightly higher than the nameplate values, because.к. No load is connected here.

So I separated one half and now we proceed to disassemble the transformer. There was a large amount of paraffin between the layers of paper.

The secondary winding in my case is wound in two layers separated by a layer of paper. To lower the secondary voltage from 18 volts I had to remove almost half of the turns.

When determining the required voltage, you must take into account that after the transformer there will be a diode bridge, which will reduce the voltage by about a couple of volts. But adding a smoothing capacitor will cause a voltage increase of about 1.4 times. Т.е. in the absence of load, the rectified voltage at the capacitor will be equal to the amplitude value.

As we rewind the secondary, we measure. Soon, I stopped at 11.2 volts, i.e.к. I was afraid of a drop in voltage when the load was connected.

When you have the transformer ready (although some people can use a ready made one with the right parameters), now it’s time to get acquainted with the circuit.

We needed to solder a diode bridge (VDS) to the output of the transformer to convert the AC current into a DC pulsating current. Diode bridge can be assembled from separate diodes or use a ready-made. When choosing the battery you should consider the ampere consumption of your electric screwdriver (choose the bridge with a margin).

Wires from the secondary winding solder to the leads of the diode bridge, where the letters AC (alternating current).

Well, after the bridge you need to solder a capacitor to smooth out the ripple. Its voltage should be at least twice that of your electric screwdriver. And the capacity is 470 uF to 2200 uF.

If you want you can add a switch and a fuse before the transformer in the circuit.

So after plugging in the circuit I measured. Idle voltage at the power supply output (when no load is connected) is 15 volts. When you start the electric screwdriver, it sags to 11.5 volts, which is the norm, so no big deal. A fully charged new battery gave 13 volts.

This is what the tool looks like from the inside. Here you can find the limiting parameters of the pushbutton and you can also see that the motor is controlled by a powerful field effect transistor.

To be able to easily connect to the power supply I took the battery apart. From this we will need the contacts. This part needs to be tinned. I can solder with rosin, but in some cases you need flux for soldering aluminum.

Of course, when soldering wires from the power supply, do not forget about the polarity, it is usually shown on the battery case. The compartment became very light. The wire was sealed with thermal adhesive.

The tests showed that the electric screwdriver coped with the tasks set by the power supply.

This article has a video detailing the process of building the power supply, rewinding the transformer, connection and test.