How to Assemble a Forester Trimmer 1080
Agree, sometimes there is a need to adjust the brightness of the lamp. Well, indeed, it is not always required that it shine at full power. If in the evening you gathered as a family in the hall room for a conversation, there is enough dim lighting. Why turn on the chandelier at full power, drive the extra kilowatt hours and overpay for energy consumption. In this case, the dimmer helps, otherwise this device is called a dimmer. With it, you can change the electrical power of the lamp and thereby adjust the brightness of the light. Many men, experts in electrical engineering and lovers of electronics, assemble a dimmer with their own hands.
The main purpose and essence of the dimmer
A few words about what a dimmer is and why is it needed at all?
This device is electronic, designed to use it to change the electrical power. Most often, in this way the brightness of the lighting devices is changed. Works with incandescent lamps and LEDs.
An electrical network supplies a current that is sinusoidal. In order for the brightness to change in the bulb, a cut-off sine wave is required on it. It is possible to cut off the leading or trailing edge of the wave due to the thyristors installed in the dimmer circuit. This helps to reduce the voltage supplied to the lamp, which accordingly leads to a decrease in the power and brightness of the light.
To begin with, we will determine what elements we need for the scheme of the dimmer control.
In fact, the circuits are quite simple and will not require any scarce parts, even a not too experienced radio amateur will be able to deal with them.
- Triac This is a triode symmetric thyristor, in another way it is also called a triac (the name came from English). It is a semiconductor device, which is a thyristor variety. It is used for switching operations in electric circuits of 220 V. The triac has two main power outputs, to which the load is connected in series. When the triac is closed, there is no conductivity in it and the load turns off. As soon as an unlocking signal is applied to it, conductivity appears between its electrodes and the load turns on. Its main characteristic is the holding current. While a current exceeding this value flows through its electrodes, the triac remains open.
- Dinistor. It belongs to semiconductor devices, is a type of thyristors, and has bidirectional conductivity. If we consider the principle of its operation in more detail, then the dinistor is two diodes that are turned on towards each other. The dinistor is also called a diac.
- Diode. This is an electronic element, which, depending on which direction the electric current takes, has different conductivity. It has two electrodes – a cathode and anode. When a direct voltage is applied to the diode, it is open; in the case of reverse voltage, the diode is closed.
- Non-polar capacitor. Their main difference from other capacitors is that they can be connected to an electric circuit without observing polarity. During operation, polarity reversal is allowed.
- Fixed and variable resistors. In electrical circuits, they are considered a passive element. A constant resistor has some specific resistance, for a variable this value can vary. Their main purpose is to convert current to voltage or vice versa voltage to current, absorb electrical energy, limit current. The variable resistor is also called a potentiometer; it has a movable tap contact, the so-called motor.
- LED for indicator. This is such a semiconductor device that has an electron-hole transition. When an electric current is passed through it in the forward direction, it creates optical radiation.
The dimmer circuit on the triac uses a phase adjustment method. In this case, the main regulating element is the triac, the load power that can be connected to this circuit depends on its parameters. For example, if you use the VT 12-600 triac, then you can adjust the load power to 1 kW. If you want to make your dimmer for a more powerful load, then choose a triac with large parameters, respectively.
Principle of operation
Before you make a dimmer with your own hands, let’s figure out what the essence of his work is.
- When the circuit is connected to an electric circuit, an alternating voltage of 220 V from the network is supplied to it. When a positive half-cycle occurs in the voltage sinusoid, current flows through the resistors and one of the diodes, due to which the capacitor is charged.
- As soon as the voltage reaches the parameter necessary for the breakdown of the dinistor, a current begins to flow through the dinistor and through the control electrode of the triac.
- This current makes the triac open. Lamps that are connected in series with it turn out to be connected to the circuit and light up.
- As soon as the voltage sine wave passes through zero, the triac will close.
- When the sinusoidal voltage reaches a half-cycle of negative, the whole process is repeated in a similar way.
- The moment of opening of the triac has a directly proportional dependence on the value of active resistance in the circuit. By changing this resistance, you can change the opening time of the triac in each half-cycle. Thus, the power consumption of the bulb and the brightness of its glow will smoothly change.
The principle of operation and the subsequent assembly of the device are described in more detail in this video:
Now we are about to assemble our dimmer. Keep in mind that the circuit can be mounted, that is, with the use of connecting wires. But it will be better to use a printed circuit board. For this purpose, you can take foil textolite (a size of 35×25 mm will be enough). A dimmer assembled on a triac using a printed circuit board allows you to minimize the size of the block, it will have small dimensions, and this makes it possible to install it in place of a conventional switch.
Before starting work, stock up with rosin, solder, a soldering iron, wire cutters and connecting wires.
Further, the controller circuit is assembled according to the following algorithm:
- Apply circuit diagrams to the board. Drill holes for the terminals of the connected elements. Using nitro-paint, draw paths on the diagram, and also determine the location of the mounting sites for soldering.
- Next, the board must be etched. Prepare a solution of ferric chloride. Take a dish so that the board does not lie snugly on the bottom, but with its corners it rests on its walls. Turn the circuit board periodically during etching and stir the solution. In the case when this must be done quickly, warm the solution to a temperature of 50-60 degrees.
- The next stage is the tinning of the board and washing it with alcohol (acetone is undesirable).
- Install the elements into the holes made, cut off the excess ends and solder all the contacts with a soldering iron.
- Solder the potentiometer using the connecting wires.
- And now the assembled dimmer circuit is being tested for incandescent lamps.
- Connect the light bulb, plug the circuit into the mains and turn the potentiometer knob. If everything is assembled correctly, then the brightness of the lamp should change.
Video: How to Assemble a Forester Trimmer 1080
As a rule, dimmers are installed in place of switches. That is, it is mounted on phase discontinuity in series with the load. This, by the way, is very important, as when connecting a switch. In no case do not mix up the phase and zero, if you set the dimmer to zero, the electronic circuit will fail. To prevent errors, be sure to check where you have phase and where zero is before installing using an indicator screwdriver.
Further, the algorithm is as follows:
- Disconnect the workplace by turning off the introductory machine to a room or apartment.
- Remove the switch from the mounting box.
- Apply voltage and on the disconnected wires accurately determine the phase and zero. Mark the detected phase in some way (with a marker or electrical tape).
- Turn off the input power again. Connect the input terminals of the dimmer to the phase wire, the output terminals are connected to the load. For factory controllers, the terminals are marked, in this case, the connection must be made according to the marking. But for dimmers there is no fundamental difference, so the phase connection can be arbitrary.
- Do-it-yourself dimmer for 220 V LED lamps is installed in the same way. The only fundamental difference is that it must be installed in front of the controller of these lamps. That is, from the dimmer, the output goes to the input of the controller.
The dimmer that you assembled with your own hands can be used not only as a power regulator on the triac for lighting. With it, you can change the speed of rotation of the exhaust fan or adjust the temperature of the tip of the soldering iron. So if you are friends with radio electronics, you are quite capable of making a triac controller. It may not make your life much easier, but the fact that you did it yourself is already good.
Many gardeners dream of seeing a well-groomed and beautiful lawn on their plot. Against the background of a neat green carpet, trees, flowers and other elements of the recreation area look quite attractive. In order for the lawn to be always well-groomed, it is necessary to trim it periodically, just in that the trimmers help the hosts.
The trimmer is necessary for everyone who has their own plot, because with it you can mow grass even in inaccessible places.
But what about lawn mowers? Such a device as a trimmer, compared with lawn mowers, is lightweight and easy to use. With it, you can safely in hard-to-reach places and on uneven surfaces where a lawn mower cannot pass, to create a beautifully trimmed lawn. With this device it is convenient to mow grass both around trees and bushes, and along walls, fences and paths.
Types of Trimmers
Trimmers are ideal for fast mowing, mostly with soft grass. Usually these are low-power devices with simple design features and with an electric motor. The trimmer is used for work on a small area, which is located next to the house or place where there is a constant power source. But the power that the trimmer has is much less compared to gasoline devices.
Types of lawn trimmers.
What are the benefits of the trimmer:
- Low noise level;
- Relatively light weight;
- Ease of starting the device;
- There is no need to constantly refuel the apparatus;
- Environmental friendly.
What are the disadvantages of the trimmer:
- Due to the low power of this device, it is difficult to cut off thick grass and thick weeds;
- Has limited movement, as it is tied to an electrical outlet.
- With the engine on top. Such devices are quite expensive, but they have a powerful engine, thick fishing line and they can be trimmed even very thick and wet grass. When working, the upper engine arrangement, as practice has shown, is more convenient due to the rational distribution of weight.
- With the location of the engine below. A lower engine is well suited for mowing soft, grassy or constantly mowed grass. But the duration of his work is short in time, that is, this device requires constant rest. This type of trimmer is strictly prohibited for mowing wet grass. But the lower location of the engine can significantly reduce power.
Types of trimmer knobs:
Scheme of the trimmer handle.
- “D” – figurative;
- “T” is figurative;
- “J” is figurative.
A person who has some experience with trimmers knows how important the shape of the handle of the device is. Therefore, in order to choose the right trimmer, you need to decide for mowing which grass it will be needed and for which territory it is bought. After all, the shape of the handle of the future trimmer depends on these factors.
- The “D” -shaped handle is ideally suited for small-sized work, but at the same time its use requires a lot of maneuverability from the worker. For example, while mowing grass along paths, fences, walls, and around trees, shrubs, and flower beds. In this case, the fishing line comes to the rescue. Most of these devices have an automatic fishing line.
- For harvesting lush thickets of grass, it is best to choose a trimmer with a “D” -shaped handle, which is additionally equipped with a “J” -shaped handle, with the possibility of installing a knife. This supplement protects against the danger of approaching a bevel gear. A “J” shaped handle is best used when the trimmer is equipped with a grass knife.
- Trimmer with a “T” -shaped handle for working in open spaces and for a large amount of work. Such a device is perfect for mowing thick tall grass and cutting thick branches, as it has a powerful three-petal knife. Also, a device with a “T” -shaped handle is suitable for large-volume work.
The scheme of the lawn mowing device.
The trimmer is equipped with a curved rod with a flexible shaft, which directly transmits torque to the cutting body. That makes it possible to use only the head with fishing line as a cutting element. In older models, the drive shaft is rigid and the bar is straight. This design provides a lower level of vibration of the trimmer, and therefore, increases the durability and reliability of the device. A person has the opportunity to use various cutting organs in his work, improves visibility and increases the area of reach when mowing.
To choose the right trimmer, you need to know at least a little about its device. It is important that such devices have a cutting element. The choice of the cutting element, and therefore the trimmer, depends on the grass that will need to be trimmed. The cutting organ of the trimmer is a head with one or more pieces of plastic fishing line attached. With the help of this fishing line, secondary lawn care takes place. During operation, the line easily cuts grass, stems of weeds and even a small shrub.
As the fishing line wears out, it needs to be replaced. For new devices, replacement occurs automatically or semi-automatically. With automatic feeding, the fishing line changes independently, during each subsequent inclusion. In semiautomatic devices, as a rule, it is enough to hit the head of the device on the ground, and the mechanism itself unwinds the required amount of fishing line.
To reduce the wear of the fishing line, a safety bracket can be placed in the trimmer above the cutting body, which prevents the fishing line from approaching the obstacle. For weeds, hard grass, young shoots of trees, you can pick up a metal knife as a cutting organ. For felling small trees, special discs with a certain number of teeth are used.
How to choose a trimmer
- Some manufacturers have in the assortment of electric and gas trimmers with removable heads, so that it is possible to change various nozzles. Thus, the buyer receives a multi-tool, which can be easily turned into a cultivator, brush cutter and snow blower. At the same time, the scythe for cutting grass is easily disassembled.
- When purchasing a trimmer, be sure to check the ergonomics of the device and ease of operation.
- It should take into account the balance of all parts, the convenience of the handle and steering wheel. Because it affects the balance of the mower during work.
- Significantly reduce the load on the human body shoulder straps. And to increase the coverage area will help a long detachable rod.
- For higher efficiency when mowing grass, the device must have high power and fast acceleration.
- The weight of the device relative to its power should be minimal.
- The engine should be easy to start, and it should be equipped with a special device that helps to reduce the emission of harmful substances into the environment.
- It is desirable that the trimmer be equipped with a system for absorbing and minimizing vibration of parts with which a person will be in direct contact during operation.
Today, trimmer manufacturers offer consumers such a wide range of models that every customer will find exactly the device that suits him in all technical characteristics. Choosing a trimmer, you should not forget about the features of the lawn and the frequency of use of the device in practice.