Every home craftsman has a reliable assistant - a screwdriver. Excellent and durable device. The only problem is that the tool needs a constant load. Surprisingly, it was without a permanent job in normal mode that the screwdriver quickly fails. We are talking here about the battery options of devices. Batteries should charge on the engine, and not be discharged arbitrarily.
Scheme of the device cordless screwdriver.
What is the problem?
In case of spontaneous discharge of batteries, an irreversible process of destruction of their elements takes place. Repair such batteries are not subject. The second negative point is also that it is very problematic to buy a new battery for a screwdriver: they are available only from the official representatives of the companies that produce these devices.
The cost of the battery is always very impressive. This is where the problem of choice arises: to buy a new battery or buy a new screwdriver (not much more expensive). You can give your device a different status by supplying it with electrical power. This option seems the most promising. You immediately get several benefits:
Scheme of the network screwdriver.
- Charge the battery for the screwdriver will not have to, therefore, reduced downtime.
- The torque of the screwdriver will be constant, since the current will not fall as the battery discharges.
- A long period of non-use of a screwdriver will not affect its technical characteristics.
There is only one drawback to the network screwdriver - for work, you must have an electrical network in the immediate vicinity of the work site.Back to table of contents
Required materials and tools
Transforming the cordless screwdriver into the mains is not as difficult as it may seem. With certain skills and all the components, this process will take quite a bit of time. Namely, it is useful to you:
- the charger from the screwdriver;
- old ("native") battery;
- soft electrical cable (stranded);
- soldering iron and solder;
- insulating tape.
Getting started and solutions
The electrical circuit of the screwdriver.
First, the ends of the cable must be soldered to the terminals of the charger. The copper wires of the cable and brass contacts can be soldered only after pre-treatment with acid. It is often recommended to use special solder for this, but it is not usual for an ordinary person to go into the details of the process, therefore we use the simplest and most proven methods.
Acid treated contacts and wiring are easily soldered. In practice, many even get away from this: you can use clamps instead of soldering (“crocodiles”).Back to table of contents
A good old battery
But to the contacts of the screwdriver, the wire will have to be soldered, since the clamps will constantly slide off during work. For maximum reliability and convenience, it is recommended to use an old battery from a screwdriver. It must be disassembled and the inside of the battery removed. This operation will be associated with harmful substances, therefore it is strongly recommended to use skin and respiratory protection. We dispose of the entire “filling” of the battery or hand it over to a collection point for used batteries.
The battery case of the screwdriver is cleaned. It is necessary to use a weak alkaline solution for this, followed by washing with running water. We wipe the case and let it dry. From the inside you have to solder the free ends of the electrical cable, observing the polarity.
Diagram of lithium battery screwdriver.
Violation of polarity will lead to the fact that the screwdriver rotates in the opposite direction. There will be nothing wrong with this, but you will have to get used to the new position of the reverse switch.
Skills you get quickly, so this inconvenience can safely be considered temporary. Before soldering, the electrical wire must be passed through the bottom of the case, making a hole in it. In the place where the wire enters the case, it is securely fixed from the inside. You can use for this piece of insulation thicker wire and insulation tape.Back to table of contents
We pass an electric cable through the insulating layer and fix it with insulating tape. Several layers of electrical tape will make it thicker, which will not allow the wiring to stretch through the hole and prevent it from breaking. The body of the former battery needs to be connected, after adding a counterweight inside it. The fact is that the cordless screwdriver in the initial version had a center of gravity in the area of the handle. Such a distribution of mass created an additional burden on the whole hand, but it facilitated the work of the hand.
The displacement of the center of gravity will cause the load on the brush to increase significantly, so the screwdriver will be very uncomfortable. Hence, there is a need for underweight former battery. You can make a counterweight of molded rubber: it has a good density, and the closure will not threaten you. To prevent the counterweight from vibrating inside the battery case, it is recommended that rubber be cut with a small overlap. By slightly bending it, you can position the rubber inside the case so that it will not fluctuate and will become an additional short circuit protection.
Screwdriver battery charging circuit.
"Empty" battery can be inserted into the screwdriver and start working. What to do if the charger is out of order or is not available? Recommend to use for this battery from other equipment. Good advice, but on one condition: the battery parameters should be combined with the characteristics of the screwdriver. Voltage is by itself, but pay attention to the strength of the current. A car battery will force the screwdriver to work, but excessive current will cause the electric motor to overheat quickly, which will soon cause it to break.Back to table of contents
Car battery and portable power supply
Using a car battery to connect a screwdriver can be considered a good alternative if you need to work away from the mains. To work in this mode a large period of time should not be. The connection will be the same as when connected to a charger. It is enough to disconnect the clips from the device and connect them to the battery.
Another way to upgrade a cordless screwdriver to a power tool is to create a portable power supply. The screwdriver itself only needs to connect a flexible cable to it (as described earlier), on the second side of which an electrical plug is mounted. The power supply is created separately. You can take for this a finished transformer, equipping it with a rectifier. The transformer is suitable for anyone, as long as its parameters are combined with the characteristics of the screwdriver.
To make transformer coils on your own for an unprepared person will be too difficult. Yes, and to make a mistake in choosing the diameter of the wiring and the number of turns is too simple, so you should not take such a step. And if we take into account the amount of modern technology, which for various reasons is no longer used and has the necessary transformer in its design, the manufacture of various kinds of parts and devices does not make sense at all. It is enough to pick up the necessary transformer and make a rectifier for it.
The rectifier bridge is easy to solder on its own, using semiconductor diodes for this. The soldering of the rectifier and its connection will be coordinated with any available circuit. The main thing that the diodes were suitable parameters. It makes no sense to give precise figures, since it is your screwdriver that can have certain design features for which all the details need to be selected individually.Back to table of contents
Power supply from an old computer
The scheme of building a typical power supply from a computer.
To avoid such complex work will help the use of the power supply from the old computer. Almost universal transformer: you can get any currents at the output, the main thing is not to confuse the wires. Such a transformer is suitable for any screwdriver.
Since the power supply from the computer is provided with a cooling system, then for its durability you can not be afraid at all. Retrofit of such a device is necessary only insulating housing and grounding. An electrical outlet is mounted on the housing of the rectifier. It will be very convenient and easy to work with such a device. To ensure emergency shutdown, the power supply must be equipped with a button (toggle switch). Computer power supply has a button on the back.
Homemade power supply for the screwdriver is recommended to retrofit the LED light bulb. So you will know for sure if there is voltage on the coil winding. For a computer unit, such a need is irrelevant, since the connection to the network is indicated by working noise from the cooler.Back to table of contents
Old inverter welding
Used to upgrade the screwdriver and end-of-life inverter welding. The currents here are completely different, but a small improvement allows for good results. It is necessary to add only the secondary coil, and all other components are quite suitable for use.
But, unlike the computer power supply, the inverter unit will have to be subjected to careful research and many calculations in order to achieve the proper voltage and the required current strength at the output. Without a good radio training you just can not do. Unless the case from the inverter is suitable, without any restrictions.
The network cable for the upgraded screwdriver must be flexible and have a high degree of reliability in electrical parameters.
When working in conditions of high humidity, this factor may be very important.
Home craftsmen who have already transformed their cordless screwdriver into a network one recommend using simple and useful rules when using it:
- the power screwdriver needs some rest (about 5 minutes) after every 20 minutes of work;
- so that the electrical cable does not interfere with operation, it must be fixed on the arm (near the elbow) and have a small margin between the elbow and the arm;
- the power supply requires regular dusting;
- the power supply should not be connected to the network using a large number of extension cords;
- without grounding the power supply to work with him is strictly prohibited;
- for high-altitude work (more than 2 m above the ground level) converted under the network screwdriver is not allowed.
If you follow these simple rules, your new or updated tool will last much longer. The disadvantage will be the loss of a substantial share of mobility, but in return you will receive a unit that does not require constant recharging and the purchase of new batteries, so the savings are obvious.