A description of how to convert a cordless screwdriver into a corded one is offered to the attention of the home craftsman. The fact is that during long breaks in the operation of the tool, and therefore during spontaneous discharge of the batteries, these current sources are irreversibly destroyed. Buying a new battery is often problematic, and it costs a lot. Powering the screwdriver from an electrical circuit is a very promising way to solve this problem.
In order not to worry about charging the screwdriver, the cordless screwdriver is converted into a mains one.
Not only will the life of the instrument be extended, but its owner will also receive several undeniable advantages as a bonus:
And there is only one drawback: there must be an electrical network near the place of work.
Any tool of this kind includes two parts:
The electric motor is most often powered by a battery designed for an operating voltage of 12 V and a current of about 1.5-2.5 A. Its charge usually lasts no more than an hour of hard work, and then it needs to be recharged, which usually takes several hours . The current for charging the battery is supplied by the charging unit. All this time the tool is idle. To change the direction of rotation of the rotor, it is enough to reverse the direction of the current, so the switch simply changes the polarity of the voltage supplied to the electric motor.
As mentioned above, rechargeable batteries require special storage conditions between tool uses. With periodic spontaneous discharge, processes of irreversible destruction of the elements begin in them, and they are no longer subject to repair. You can, of course, buy a new battery, but, firstly, they are not always on sale, and secondly, they often cost so much that you have to wonder: wouldn’t it be easier to buy a new screwdriver?
A solution may be to use batteries from other technical devices. An example of such a solution would be the use of a car battery. The main thing is that its output voltage matches that for which the screwdriver motor is designed.
The failed power tool battery is removed from its compartment, which is thoroughly cleaned and washed first with a weak alkaline solution, then with clean water, after which it is wiped and dried. Any other alteration of the instrument should begin with the same.
The wires of the cable intended for supplying power from the car battery are soldered to the connectors to which voltage was supplied from the internal battery. The cable is first passed through a hole made for this purpose in the lower part of the housing. If after checking it turns out that the cartridge is rotating in the wrong direction, it’s okay: just change the wires at the battery terminals.
It’s even better if you have a battery of lithium batteries from a damaged laptop. Its elements usually fit without problems in the compartment of the tool’s “native” battery. The housings of individual battery cells must be reliably insulated from each other, and the terminals must be connected in compliance with polarity to the connection points of the old battery terminals. This battery can be charged from an existing charger.
The option of replacing a failed battery with another one taken from another electrical device is not always feasible. Then the screwdriver can be turned into a device powered by a 220 V lighting network. You just need to purchase or make your own power supply with the output voltage and current for which the electric motor is designed.
As you know, the mains power supply can be either transformer or switching. The second option is preferable because such devices are smaller in size and weight. If you have a choice, you should first measure the dimensions of the compartment that is vacated after removing the damaged battery. Then select a power supply with suitable output characteristics that fits in the vacated compartment.
Then you need to place the power supply elements in this compartment and securely fasten them there so as to exclude the possibility of short circuits. It remains to solder the output conductors of the power supply to the terminals of the former battery, and to its input - the conductors of the power cord. After this, all that remains is to assemble the body and check the operation of the tool.
It is unlikely that it will be possible to place all the elements of a transformer power supply of the required power in the screwdriver housing. There are two ways to solve this problem:
When performing any options for converting a cordless power tool to a mains power tool, one should not forget about electrical safety; uninsulated contacts should not be left.
The conclusion suggests itself: converting a non-working cordless screwdriver into a corded one is relatively easy.
This means that many household chores will become easier to do.
How to convert a cordless screwdriver to 220V? About a year ago I discovered that my Ryobi 18V tool battery had become unusable and since I was working overseas I was unable to get a new one. So I came up with a device to safely run my tools on AC (household current) and stop worrying about my tools stopping functioning on the way to work.
I've enjoyed all the benefits of battery powered power tools... They're convenient, portable, and you can often get a whole range of tools that all run on the same battery. And then the inevitable happened - the diodes on the charger began to blink strangely, and the battery began to discharge almost instantly.
I was faced with two options: drop a few thousand on a new set of batteries or try to rebuild them myself. I didn't like either of these options and I didn't have time to order parts from overseas. As with everything in my situation, for an alternative solution I searched for information on the Internet. I found some guys who connected car batteries to their drill, but I dismissed that idea too. And then I came across the idea of using an old laptop power supply instead of batteries...
The voltage was correct, but, alas, its power was too low. Even at 180W, the most powerful PC power supplies couldn't provide enough current to overcome the inrush current of my circular saw or angle grinder.
The operating principle of the PC power supply suited me, I just needed something more powerful. After a little research, I discovered that the power supply for a laptop is what is called a "switching power supply". It turns out that switching power supplies are very common in the world, they are affordable and come in a variety of voltage and power ratings... I ended up choosing a 350W AC/DC power supply made by a reputable company, Meanwell, with a DC voltage range of 15-18 volts.
Connecting a power source to a discharged battery is very simple, and in this manual, converting a screwdriver to a mains-powered one with your own hands is described in detail.
Before you begin, please understand that you have a power supply capable of discharging 20 amps. Although the assembly is quite simple, if you are not comfortable working with electronics, then it is better to seek professional help.
The cable coming out of the battery and the DC connector from the power supply are made from a standard 120V AC plug. The plug and cable were chosen due to availability and the ability to use a standard extension cord if necessary.
Under no circumstances will I connect an AC powered device, tool, or other equipment to this power source. If you decide to create this device, think ahead about who might use it. If there is a chance that someone else not trained to use this machine could use it, I would suggest making a different type of connector and cable - something more unique, but capable of carrying current.
Materials:
Tools:
Cut off the female end of the power cord (16 gauge). The remaining cord length is up to you.
Remember that this cord will be connected to your power source, but you can always use an extension cord if your instrument will be located far from a power source. I think that a meter or two will be enough.
Lay the wire. There are 2 options
Option A: Drill a hole in the battery cover to match the diameter of the outer sheath of the wire. The location of the hole is your choice. You can place a rubber boot over the wire where it exits the battery pack to relieve the stress of bending it.
Option B: Install the rotary adapter. This adapter will allow you to rotate the cable from the front to the back of the battery pack anywhere at an angle of 180 degrees. This tutorial will use a rotary adapter. If you have access to a 3D printer, you can download the STL files from www.thingiverse.com and print them - search for "18V Battery Swivel Cable Lock".
Cut about 15 cm of outer insulation from the cable, expose and tin about 5 mm of wires.
The rotary adapter consists of (3) parts:
Make sure the clamp halves can completely surround the outer sheath of the cable. Sand the inside of the clamp halves until they fit snugly against the cable insulation.
Now it's time to make a housing for the power supply.
The weakest point in household screwdrivers is the battery. Like any galvanic element, it has its own service life. The battery for a screwdriver lasts on average 3–4 years, no more, and then must be disposed of. By the way, claims that with proper care and maintenance it will last 10 years are clearly exaggerated.
How to give a screwdriver a second life if the battery has failed?
There is a way out, and there is more than one. You can purchase a new battery. But the price of such a device may exceed the cost of the entire instrument purchased several years ago. Therefore, the most acceptable solution would be to convert the screwdriver to mains voltage.
One solution would be to create a power supply yourself. There are many options for creating a homemade power supply:
Making a switching power supply for an 18 V hand tool with your own hands is not at all difficult. For this you will need:
The electric drive of the screwdriver can be driven from a 220 V network by a network adapter. It can be purchased ready-made - the price allows it. You can do it yourself. The purchased adapter must be inserted into the battery housing of the screwdriver, having first removed the batteries. The only drawback is the short length of the cord.
If you need to make a power adapter yourself, then a laptop charger is ideal for this.
The process of converting a cordless screwdriver into a corded one is simple and does not take much time. To do this you need to have:
The rework process includes the following steps:
Another solution for converting a cordless screwdriver to a 220 V network is to use an electronic transformer.
Materials for assembling a transformer power supply
To do this you need the following details:
The reader, having familiarized himself with the information presented in this article, can give his screwdriver a second life. To do this, it is enough to choose the most acceptable method of converting a battery tool for a 220 V network.
Those who have used a cordless screwdriver at least once could not help but appreciate its convenience. Without getting tangled in wires, at any time you can penetrate the device into hard-to-reach niches, bring it to the dacha, or take it outside and patch up the playground. But all the advantages of such a device are good until the battery runs out.
Today, a screwdriver is one of the devices that we use very often in everyday life. It is also indispensable in production. This device is suitable for various electrical installation and construction work. It is used to assemble furniture and other items whose design requires threaded connections.
The battery-powered screwdriver is compact and portable. But not everyone is happy about these advantages, because the device’s battery quickly runs out and you have to stop working halfway through the journey. Therefore, many owners of this tool are interested in the question of how to convert a screwdriver with a battery to a mains one.
The reason for this decision is also the fact that when the device is not used for a long time, the battery discharges on its own, which leads to the breakdown of the screwdriver due to the destruction of some elements. It is impossible to repair a failed battery, and it is not always possible to purchase a new one. Often, components can only be purchased from official representatives of the manufacturer. Accordingly, the cost of a new battery will be almost equal to the cost of a new screwdriver. Therefore, some craftsmen come to the decision to turn the screwdriver into a network one.
Materials and tools required for this:
First, you need to solder the loose ends of the cable to the terminals of the charger. You need to know that copper cable wires with brass contacts can be soldered only after treating them with acid. Experts recommend using special solder, but sometimes the simplest methods are used in the form of acid treatment.
In order for you to be able to use a screwdriver at any time without unnecessary wires, even in the most inaccessible places, convert the mobile screwdriver to a network one.
Carrying out such a procedure is not as difficult as it seems at first glance. If you have the appropriate skills and all the necessary components, this process will take a little time.
Methods for converting a cordless screwdriver into a corded one vary in complexity. One of them is that powering the charger from a laptop requires practically no knowledge and skills. To install a computer power supply, you need to be able to use a soldering iron, and to repurpose a Chinese adapter, you need to be able to use a measuring device. In addition, there are several other methods for converting a cordless screwdriver directly into a network one.
Namely:
For brainy craftsmen, performing such manipulations is not difficult. If you are not confident in your abilities, then it is better not to take risks and seek the help of a knowledgeable specialist.
If the battery fails, a household screwdriver can be switched to mains power by making some changes to its design. This will not require a large expenditure of money, time and effort. The positive nuances of such a transformation are obvious: you will not need to constantly charge the battery, and at the same time, forced downtime will disappear. After all, the shortest duration for charging the device is more than 3 hours.
However, when deciding to make such a conversion with your screwdriver, you should understand that from now on you will need alternating current to work with it. You will no longer be able to use it away from communications.
If you need to connect the screwdriver to the network, you can use the charger from an old laptop. It has characteristics similar to a screwdriver, and can easily be found in every home or workshop. But still check what output voltage is shown for your charger. In this case, 12–19V chargers are suitable.
Scheme of your actions:
This manipulation will allow you to use the screwdriver at any time, and without stopping to charge.
A great helper in the home is a cordless cordless screwdriver. Almost everyone who he has never let down can agree with this. Those whose work stopped halfway have a completely different opinion. This tool will help you always and everywhere, but only until the battery runs out. In addition, the quantity in it is limited. In moments of idleness, the battery can also deteriorate. Typically, batteries last no more than three years. When this time expires, it has to be replaced or sent to a museum of obsolete things. The situation can be resolved if you convert the screwdriver into a network one. There are a sufficient number of ways to do this.
The device's power supply provides the function of changing alternating current with a voltage of 220V. Standard screwdrivers consume direct current, with a nominal value in the range of 9–18V. In this regard, connection to the network is subject to the use of an electronic transformer. Products from the Toshibra and Feron brands are most suitable for these purposes.
Network transformers of these brands are of high quality and reliable in operation. In addition, they are quite compact, lightweight, and do not complicate the work with the tool. Their load characteristics match those required for a standard screwdriver. Their design has 2 input and output wires, which makes it possible to provide power to halogen lamps and other types of electricity consumers with a voltage of 12V. However, to use a converted device, you need to adhere to some rules.
Here they are:
Before each time you start working with a converted device, make sure it is in working order.
When batteries stop working due to the fact that they have simply outlived their useful life, many begin to wonder how they can correct the situation and convert their old cordless screwdriver into a mains-powered one with their own hands. After all, it is no longer possible to repair a battery with a damaged element, and the cost of a new one is almost equal to buying a new screwdriver. But the thrifty and skillful owners came up with a way out - to power the screwdriver from the mains. Some were even able to invent a device that works simultaneously from both mains and battery power. But it's better not to do this.
Finally, I began to implement my long-standing idea, namely, to provide power for the screwdriver from a 220-volt network. Undoubtedly, some of you also have a screwdriver with a worn-out, unusable battery that no longer takes a charge. I had two copies at my disposal.
The first (black) operating voltage is 18 Volts. This is what I initially wanted to power from the network, because... It fits comfortably in the hand and is quite powerful. But the button is missing. Perhaps in the future I will cut off the handle and make it into something like a drill. The second copy is designed for 12 Volts. Served for quite a long time. Of course, you can purchase a new battery or, in extreme cases, replace the banks. But still, you want to always have a ready-made tool at hand, especially since an electric drill is not always convenient to use because she's heavy. A power transformer will help us realize this idea.
A step-down transformer TS-250-36 was used. "250" is its rated power, and the number 36 means that the output voltage will be 36 V. It has an O-shaped magnetic circuit. Its windings are arranged in such a way that half of the primary is wound on the left, the second half on the right side. The secondary winding, which is located on top of the primary, is wound in a similar way.
It is not difficult to distinguish the windings from each other in a step-down transformer, because the secondary one is made of a thicker wire, and the one to which mains voltage is supplied is made of a thinner wire. This is due to the fact that a smaller current flows through it.
The windings have a symmetrical arrangement and two halves of 18 volts are connected by wire (the connection point is clearly visible in the bottom photo). I'll use one half.
But before you rewind the transformer, you need to take measurements. I urge you to be careful when working with current, do not touch live parts, and always check that the measurement limit on the multimeter is set correctly.
On the right, the voltage is measured on half of the secondary winding. As you can see, the voltage slightly exceeds the rated values, because there is no load connected here.
So I separated one half and now we begin 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 reduce the secondary voltage from 18 volts, almost half of the turns had to be removed.
When determining the required voltage, you need to 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 the voltage to increase by about 1.4 times. Those. in the absence of load, the rectified voltage on the capacitor will be equal to the amplitude value.
As the secondary unwinds, we take measurements. Soon, I settled on a value of 11.2 Volts, because... I was afraid of drawdown when connecting the load.
Once the transformer is prepared (although some may use a ready-made one with the required parameters), now it's time to get acquainted with the circuit.
A diode bridge (VDS) must be soldered to the output of the transformer to convert the alternating current into a pulsating direct current.
The diode bridge can be assembled from separate diodes or used ready-made. When selecting it, you should take into account how many amperes your screwdriver consumes (choose the bridge with a reserve).
We solder the wires from the secondary winding to the terminals of the diode bridge, where the letters AC (alternating current) are.
Well, after the bridge you need to solder a capacitor to smooth out the ripples. Its voltage must exceed the supply voltage of the screwdriver at least twice. And the capacitance is from 470 µF to 2200 µF.
If desired, a switch and fuse can be added to the circuit in front of the transformer.
So, after connecting the circuit, I took measurements. The idle voltage at the output of the power supply (when no load is connected) is 15 volts. When starting the screwdriver, it drops to 11.5 volts, which is normal, so it’s okay. A fully charged new battery produced 13 volts.
This is what the instrument looks like from the inside. Here you can find the limit parameters of the button, and you can also notice that the motor is controlled by a powerful field-effect transistor.
To make it easier to connect to the power supply, I disassembled the battery. We will need contacts from him.
This part needs to be tinned. I did my soldering using rosin, but in some cases you may need flux for soldering aluminum.
Of course, when soldering wires from the power supply, do not forget about the polarity; it is usually indicated on the battery case.
The compartment became very light. The wire was sealed with hot glue.
Tests showed that the screwdriver coped with the tasks when operating from the power supply.
This article has a video that shows in detail the process of creating a power supply, rewinding the transformer, connecting and testing.
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad |
|---|---|---|---|---|---|---|
| T | A step-down transformer | Select by voltage | 1 | To notepad | ||
| VDS | Diode rectifier assembly | PBL405 | 1 | Better more powerful | To notepad | |
| WITH | Electrolytic capacitor | 470...2200 µF | 1 | Not less than 50V |
