Options for making a power supply
There are several options on how to convert the screwdriver to work from the mains. The task is to power the electric motor of the device with an intermediate source.
Using a laptop charger
To make a 12V power supply for a screwdriver with your own hands is possible, even without technical knowledge. It is only necessary to find an unnecessary charger from a laptop, which has specifications similar to those for powering a screwdriver. The main thing is that the output voltage corresponds to the voltage sought (12-14 volts).
To achieve this goal, you must first dismantle the battery and remove the defective cells. Then follow these manipulations:
- Using a laptop charger.
- Cut off the output plug, strip and tin the ends of wires.
- Striped wires and solder to the battery input wires.
- Insulate the soldering points to avoid short circuits.
- We make a hole in the case, so as not to squeeze the wire, and make the assembly of the construction.
The base is a computer power supply
To make this device we will need the A-format PC unit. Т. It is easy to find, this is an old model of the power supply, which is easy to buy at any market of radio components. It is important to know that you can use a 300-350W unit with a current of 12 V at least 16 A.
AT format blocks meet these parameters. On the body of this device is a power button, which is very convenient when working. Inside there is a cooling fan and an overload protection circuit.
The order of the rearrangement of the block:
- Remove the lid of the housing B. П. Inside we will see a board with a lot of wires going to the connectors, as well as a fan.
- The next step is to disable the safety switch. Locate the green wire on the large square connector.
- Connect this wire to the black wire from the same socket. You can make a jumper from another piece of wire, or you can just cut it short and leave it in the case.
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Then in the bundle of outputs find the smaller connector (MOLEX) and do with it the following operations:
- Leave the black and yellow wire and cut the other two short.
- For the convenience of the PSU during work, solder an extension cord to the black and yellow wire.
- Attach the other end of the extension cord to the contacts of the empty battery compartment. This should be done by soldering, you can make a good twist, it is necessary to strictly observe the polarity.
- Make a hole in the body, so as not to squeeze the wire during assembly. Your device is ready.
If you have a desire to improve your design, t. е. Hide it in another housing, drill holes for air intake to prevent the PSU from overheating.
Make Your 12V Cordless Drill Work with 220V | IR2153 Power Supply 30A
Power from the car charger
With a car battery charger, it’s pretty easy to make a device to power a screwdriver. To make the conversion, you only need to connect the power terminals of the battery charger output to the electric motor power supply.
If you have a device for charging with continuously adjustable output voltage, you can use it as a power supply 18 volts for a screwdriver.
How to place the PSU in an enclosure. 3 different possibilities
The mains power supply for an electric screwdriver can be placed in the battery case or in the handle. Choices:
At the flea market you can pick up a PSU with the right parameters. At home, it should be carefully removed from the housing and placed in your electric screwdriver, securely fastening all components. If the wires are short, lengthen them so that they do not touch metal parts. Place the transformer and the board separately. On microcircuits for better cooling set additional heat sinks. Also not superfluous are the openings in the case, so that the air can circulate, and the heat is removed during operation.
Converting a cordless electric screwdriver into a cordless screwdriver
At the hardware store, buy a PSU for 24 V, current 9 A. Screwdrivers run on 12 or 18 volts, so the task is to reduce the voltage to the required level. Minimal knowledge of radio engineering is required to do this job. The output voltage is supported by a 2320 ohm resistor R10. Replace it with a 10k ohm trimmer resistor. How to tune the power supply is explained next:
- unsolder the constant resistor;
- set the device resistance of the trimmer resistor to 2300 Ohm;
- The resistor must be soldered in place of the constant resistor;
- With the PSU turned on, adjust the voltage.
The self-made PSU will be based on a Feron or Taschibra 60W electronic transformer. You can buy them in electrical stores, they are designed for halogen lamps. They do not require any modifications. Taking the secondary winding away from the center point allowed to use two Schottky diodes instead of the usual four. Operation of PSU is controlled by LED HL1. You can see all the necessary parts on the diagram.
Transformer T1 is wound by yourself. The non-deficient ferrite ring HM2000 is used, size 28×16×9. Before winding you clean the corners with a file, wrap the ring with FUM tape. The made unit is mounted on the aluminum plate with thickness of 3 mm or more, placed in the battery case. It also serves as a common wire.
Practical example of how an electric screwdriver works from a computer power supply
At work, there are two electric screwdriver, they were purchased and with daily use, the batteries have lost capacity and it is useless to charge them, very quickly sit down. We tried to take the battery off, but it didn’t work, so we had to make a power supply and work on it in the workshop. So, let’s check how the electric screwdriver will behave when working from the mains with a computer power supply.
I used a unit from an old computer. It’s a 220 volt. took out a wire with plug to plug in a screwdriver. What’s great is that it has an on/off switch and a light switch. Power reserve is sufficient. 2.5 meter wire.
Let’s test it in operation. Screws in screws very well, drills holes.
It took about 1.5 hours to change the unit. The test showed that there was enough power to drive the screws into pine, chipboard. Let’s try to drill a hole. As you can see, it works. There are no overloads, no smoke, etc.п.
How to convert a screwdriver to 220 volts
When the battery of a screwdriver has finally become worthless, and replacing the acb is not possible, there is still the best and most budgetary solution. to convert it to 220 volts. Yuri Onishchenko reviewed what kind of power supply you need, what to connect, and other points with the conversion. All the parts you need can be purchased cheaply from this Chinese store.
What is available for converting the electric screwdriver in our case? Laptop 15 volt, 6 amp power supply. I also have a computer PSU, a bit rewired, but there are no changes in the schematic. Power supply from a halogen bulb. Lamp power is 12 volts, 50 watts. There is a battery charger for car batteries with current regulator. This will be used as a power supply and a separate ammeter.
Here we go. Let’s start connecting directly from the power supply. The leads are already wired in. 12 volts, 3 amps idle. Maximum ratchet. As you can see on the meter, the current is up to 8 amps.
Let’s try a laptop PSU for fifteen volts, six amps. Idle current of 4 amps. In ratchet mode, the maximum current is 9 amps, the voltage is 14 volts. It turns out that a 6-amp power supply can do the job.
It’s my computer box’s turn. It is quietly bearing the load.
The home handyman rarely uses plumbing tools. A cordless electric screwdriver lies idle for a long time. And during this period, there is an arbitrary discharge in the power source, which leads to changes in the internal design.
By converting an electric screwdriver to 220 volts, the home handyman gets such benefits:
- no time-consuming charging is required;
- storage does not cause any disturbance in the construction of the tool;
- Power supply provides constant torque.
The minus of the converted electric screwdriver is one: the attachment to the mains.
Important! Dismantled and removed from the body, the battery can not be thrown in the trash. It is disposed of in specialized services.
How to convert a cordless screwdriver for 220 volt operation?
Methods of converting a cordless screwdriver to work from the mains vary in complexity, most often you need to connect the electric screwdriver directly to the charger. Connecting a laptop charger requires almost no knowledge, to install a computer power supply you need to be friendly with a soldering iron, and to reconfigure the Chinese unit master should be able to handle measuring tools. The native power supply of an electric screwdriver is usually not designed for that to connect the electric screwdriver directly, its power is designed only for charging the battery. When you connect an electric screwdriver to the native charger directly, it barely spins, because the.к., he clearly lacks current. An electric screwdriver consumes about 2A at idle, when powered by a 12 volt, if you try to stop it, the current consumption will increase from 7 to 20A, take it into account when choosing a power adapter. If you do not want to lose torque, you need to pick up the appropriate power supply.
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 you need to connect the electric screwdriver directly to the charger. Connecting the battery charger from a laptop requires almost no knowledge to install a computer power supply unit need to be friendly with a soldering iron, and to reconfigure the Chinese unit the master must be able to handle measuring tools. Be aware, the native power supply of an electric screwdriver is usually not designed to connect the electric screwdriver directly, its power is designed only to charge 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 mains, you can help an unnecessary charger from a laptop, as it has similar characteristics and easily found in any home. First you need to see what the output voltage of the battery charger is. 12-19V chargers will work.
It is important to check the voltage and current of the charger
You will need to modify the battery pack, for this you need to disassemble it and take out the failed batteries.
- Take a laptop charger.
- Cut off the connector and strip the wires of their insulation.
- Take the bare wires and solder them. If there is no such a possibility, wrap them with duct tape.
- Make a hole in the body for the wire and assemble the construction.
Use an external power supply from a computer
So you need an AT-format power supply. It is likely that you will find it at home, but you can easily buy an old working power adapter at any radio market. Its cost is unlikely to be great. It is very important to remember that the power supply is suitable, with a capacity of 300-350W, and the current in the 12 V circuit is not less than 16A.
The computer unit type “AT” will power the screwdriver
- Unscrew the case of the power supply. Under the case you will see the fan, the board and a lot of wires that go from the board to the connectors.
- You need to remove the power protection. Locate the green wire on the large 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 housing. Alternatively you could use a jumper made from a small piece of wire.
Contacts of the connector: yellow wire: 12 V, red wire: 5 V, black. ground
- Cut the unwanted wires, leaving the yellow and black.
- Using a piece of wire as an extension cord so that the power supply can be in a convenient place when working, 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 of such alteration is not different from the way with the laptop charger. Thanks to the current trend toward compact pulse chargers, linear analog devices with manual controls can be purchased at the auto market at a very attractive price. If the voltage on the battery changes smoothly, it will fit to absolutely any screwdriver, and remaking 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 the so-called “crocodiles”, on the free end strip the wire from the insulation by 2-3 cm.
Cut off the terminals and strip the wires
Bend the wires with a hook to connect to the terminals
Taking the Chinese power supply board
So we are talking about a power supply with 24V output voltage and a maximum current of 9A. Screwdrivers are usually designed for 12V or 18V, so you first have to 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 the R10 position is responsible for the output voltage. Its nominal value is 2320 Ohm. Instead of this resistor we 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 solder out a permanent resistor
Solder a trimmer resistor to the board instead of the DC resistor
to adjust the output voltage and check the unit characteristics
Power supply of the electric screwdriver from 220V
Finally I have begun to implement my longtime plan, namely, to power the electric screwdriver from 220 volts. No doubt some of you also have a screwdriver, with a worn out, unusable battery that no longer takes a charge. At my location had two copies.
The first one (black) has a working voltage of 18 volts. It was him I originally wanted to power from the network, t.к. It is convenient in the hand and is quite powerful. But there is no button. Maybe in the future I will cut the handle and make it like a drill. The second one is designed for 12 volts. Has been in service for quite a long time. Of course you can buy a new battery or if necessary replace the cans. But still want to have always a ready tool at hand, especially since an electric drill is not always convenient to use t.к. it’s heavy. To implement this idea will help us power transformer.
Was used step-down transformer TC-250-36. “250”. 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 in such a way that half of the primary is wound on the left side, the other half on the right side. The secondary winding is wound in a similar way and is located on top of the primary winding. It is easy to distinguish the windings from each other in a step-down transformer.к. The secondary is made of a thicker wire, and the one with the line voltage is made of a thinner wire. This is because it carries a smaller current.
The windings have a symmetrical arrangement and the two halves of 18 volts are connected with a wire (you can see the connection point on the bottom photo). I will use one half.
But before you rewind the transformer, you need to measure. I urge you to be careful when dealing with current, do not touch live parts, and always check if the multimeter has the right measurement range.
On the right you measure the voltage on half of the secondary. As can be seen, the voltage is slightly higher than the rating, i.e.к. No load is connected here.
So I separated one half and now proceed to disassemble the transformer. There is 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 need to consider that after the transformer 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 absence of load, the rectified voltage on the capacitor will be equal to the amplitude value.
As we are winding off the secondary thread, we measure. Soon, I settled on 11.2 volts, i.e.к. I was afraid of sagging when connecting the load.
When the transformer is prepared (although some may use a ready made one with the right parameters), now it’s time to get acquainted with the schematic.
You need to solder a diode bridge (VDS) to the output of the transformer to convert alternating current into a direct pulsating current. Diode bridge can be assembled from separate diodes or use a ready-made diode. When selecting it should take into account how many amps your electric screwdriver consumes (the bridge to pick up with a reserve).
The wires from the secondary winding solder to the diode bridge terminals, where the letters AC (alternating current).
Well, after the bridge you need to solder a capacitor to smooth out ripples. Its voltage should exceed the supply voltage of an electric screwdriver at least twice. And capacity from 470 uF to 2200 uF.
If you want, you can add a circuit breaker and fuse before the transformer.
So, after connecting the circuit I made measurements. Idle voltage at the power supply output (when the load is not connected) is 15 volts. When you start the electric screwdriver, it will drop to 11.5 volts, which is normal, so it’s no big deal. Fully charged, the new battery gave 13 volts.
Mains power supply for electric screwdriver
This is what the tool looks like from the inside. Here you can find the limits of the button and also you can see, that the motor is controlled by a high-powered field-effect transistor.
To be able to easily connect to the power supply I took the battery apart. From it, we need the contacts. This part needs to be tinned. I had to solder with rosin, but in some cases you might need flux for aluminum soldering.
Of course when soldering the wires from the power supply do not forget about the polarity, it is usually indicated on the body of the battery. The compartment became very light. The wire was sealed with hot melt glue.
The tests showed that the electric screwdriver did the job with the power supply.
This article has a video that shows in detail the process of building the power supply, rewinding the transformer, connection and test.
I tell you how to convert the screwdriver to 220v power
Cordless electric screwdriver is a handy tool that you can carry everywhere. But it works only as long as there is charge in the battery, after which the tool must be put on charge. But the battery usually lasts less than the tool itself. Most batteries do not last more than three years, after which it must be replaced.
If you do not have the opportunity to do this, you can always use an electric screwdriver, turning it into a mains. To do this, you only need to make small changes to connect an electric screwdriver to an ordinary household network of 220 volts.
Operating from the mains via charger
The easiest way to power an electric screwdriver from 220 volts is to use the charger that was used to recharge the battery. This does not take much time or effort. To do this, proceed as follows:
restoration/change voltage from 110v to 220v / Makita electric chainsaw of Japan
Attach two wires to the charger of the electric screwdriver. You can use alligator clips for this, or solder the wires with a soldering iron.
Remove the discharged battery from the tool, disassemble it and take out the cells that are not working.
Make holes in the case through which the cable will be passed. To prevent the wire from dropping out, it must be sealed with heat shrink or electrical tape.
Add something heavy into the battery case, about the same weight as the removed cells, to make sure the tool is properly weighted.
Solder the wires connected to the charger to the terminals from the battery.
Reassemble the case and put it back into the electric screwdriver.
Done! You can try out a corded electric screwdriver for yourself. It is only important to remember that with this method of connection losses in the cable will be quite large, so the wire from the charger to the electric screwdriver must be no more than a meter, and in the cross section of 2.5 squares or more.
Powering through the power supply
Another way to connect an electric screwdriver to the mains is to use a power adapter that will draw current from the mains and give the tool the necessary level of energy. It can be placed in the battery case. this allows not only a convenient design, but also the correct weight distribution of the tool. This is how it is done:
The old battery is disassembled and the dead cells are removed.
The ready-to-use power supply is installed in the housing, and the terminals for high and low voltage are connected.
Assemble the battery housing and put it back in place.
In this option, you need to consider that the power supply can overheat in an enclosed space. For this purpose, several holes are made in the walls of the housing before installation.