How to Make a Power Screwdriver
Those who used a cordless screwdriver. appreciated its convenience. At any time, without getting confused in the wires, you can crawl into hard-to-reach niches. Until the battery runs out.
This is the first drawback. it needs regular recharging. Sooner or later, batteries will exhaust their recharge cycle life.
This is the second drawback. This moment will come the sooner the cheaper your tool. Saving money when buying, we most often purchase inexpensive Chinese "no-name" devices.
There is nothing wrong with this, but be aware: the manufacturer saves as much as you do. Therefore, the most expensive unit (and this is the battery) when bundled will be the cheapest. As a result, we get an excellent tool with a serviceable engine and an unworn gearbox that does not work due to a poor-quality battery.
There is an option to purchase a new set of batteries, or replace faulty batteries in the unit. However, this is a budget event. The cost is comparable to buying a new screwdriver.
The second option is to use a spare or old battery from the car (if you have one). But the starter battery has a lot of weight, and using such a tandem is not very comfortable.
There is a way out. remaking a screwdriver in a network
Yes, one of the advantages of a cordless tool is lost. mobility. But for work in rooms with 220 volt access to the network, this is an excellent outlet. over, you give a new life to a broken instrument.
There are two concepts how to make a network of a cordless screwdriver:
- External power supply The idea is not as absurd as it may seem. Even a large and heavy buck rectifier can simply stand near a power outlet. You are equally attached to the power supply, and to the plugged in mains plug. A low-voltage cord can be made of any length;
Accordingly, the power cord for 12-19 volts should be with a larger cross section than 220 volts.
DIY screwdriver alteration
Consider the option with a remote power supply
Using a power supply from a personal computer.
On the radio market for a small cost, you can purchase an old power supply from a personal computer. We need the “AT” format option, which had to be turned off with the key after exiting the operating system.
Users with experience remember such system units. The advantage of such a power supply is that it indicates honest power. If 300W is written, it means you can safely remove 15-16 amperes from a 12-volt output (again we turn to Ohm’s law). This is quite enough to power an average screwdriver.
Such blocks have a power button in the kit. Another advantage is the presence of a cooling fan and an advanced overload protection system. If you will hide the power source in a beautiful case. do not forget to leave a ventilation hole.
The connection is very simple. Black wire (-), yellow wire (12V).
Limitations. a screwdriver with a supply voltage above 14 volts will not work.
Видео: How to Make a Power Screwdriver
Using a car battery charger.
The principle is the same as using a computer power supply. You need to purchase an old charge unit for starter batteries. The modern fashion for compact pulse chargers has left analog linear devices outboard, with manual adjustment of voltage and charge current. Therefore, such a device can be purchased in the automotive market for a symbolic price.
Well, if the voltage can be regulated smoothly. in this case, your makeshift power supply will fit any screwdriver. Converting it to a network tool comes down to connecting the input of the electric motor to the power terminals of the charger.
Making a homemade power supply.
If you are familiar with the principles of building electrical circuits, you can independently make a power supply. A diagram giving general concepts is illustrated.
The transformer can be selected from an old tube TV, or other household appliances. Power over 220 volts 250-350W. The main thing is the power supply. the donor should not be pulsed.
The voltage on the secondary winding is 24-30 volts. The secondary winding is made of a wire of the corresponding cross section. However, if the current of the output winding is at least 15 amperes (see the specification of the transformer), there is nothing to worry about. After losses on the diode bridge (1-1.5 V on the diode), you will get the required output value.
If you have an electrical education. make the calculation yourself. Or in a practical way: by connecting a 220 volt 100W incandescent lamp as a load, measure the output voltage. If it exceeds the needs of a screwdriver. reduce the number of turns of the secondary winding of the transformer.
Mains power supply for a screwdriver in a battery case
If your tool is not too powerful, you can place the power supply in a pen or case from damaged batteries.
We build in the finished power supply.
To do this, you need to purchase a ready-made unit with suitable characteristics and dimensions. On the radio markets, such good is enough. Take the case with you, and go to the fitting. When the desired power source is purchased. carefully separate it from the case.
We place in a box from the batteries of the screwdriver. All components must be securely fastened. If necessary, extend the wires connecting the control board and the transformer. If the circuit touches the metal parts of the transformer during operation, a short circuit will occur.
Since the space in the case allows. carry the board and the transformer for better cooling. Whatever high-quality power supply you choose. the load will be high, and overheating is possible.
It will not be superfluous to fix additional radiators on the power control microcircuits. Work with a screwdriver for a long time, unplug it from the network and touch the radio components on the control board.
You yourself will understand what elements need heat removal. In the case, you can make holes for air circulation.
Altering the power supply unit with your own hands will not take much time, and the cost of the purchased module is incomparable with restoring the battery.
Homemade power scheme.
If you are with a soldering iron on "you". this material is useful as an instruction.
The scheme is implemented on the donor in the form of a ballast to a halogen floodlight with a capacity of 150W. The added components are indicated in the diagram with colored inserts.
An output transformer from the old computer power supply was added, and Schottky diodes were taken from the same place. The middle point of the secondary winding is between a pair of 12 turns each. Since this circuit does not start without load, a 15W incandescent lamp is constantly turned on at the output. At the same time, a backlight scheme is implemented.
The power supply fits easily in the battery case.
The design turned out so successful and inexpensive. that the idea came to put production on stream. With an abundance of cheap Chinese screwdrivers, demand will be provided.
In conclusion, watch a video of altering a screwdriver on a network with a selection of a power supply to it.