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About dimmers
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What was a dimmer?
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How does a dimmer work?
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Which dimmer fits which bulbs?
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What types of dimmers are there?
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What should you pay attention to when buying dimmers?
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The most common questions about dimmers
What was a dimmer?
Dimmable light sources create a perfect environment.
A dimmer is an electronic component with which the power supply to connected lamps or lamps can be adjusted continuously. Depending on the situation, the brightness of the lighting can be adjusted individually.
What was perfectly working at home on a comfortable television evening with a good film can also be used perfectly in presentations in meeting rooms: The light intensity of the ceiling lamp is reduced so that the high-contrast television picture is displayed well but does not fade.
Just like in the corner of the sofa, work benches and desks can also be used to adjust the respective workplace lights to the optimum brightness. The lamps for room lighting can then be adjusted back to a pleasant brightness value. This saves energy costs and the lower energy requirement relieves our environment.
With dimmable lights, the possibilities of individual lighting are extremely varied and can be perfectly adapted to different situations.
How does a dimmer work?
A dimmer works with 230 V AC mains voltage, which has a frequency of 50 Hz. This means: For example, a bulb is supplied with 50 positive and 50 negative half waves per second.
The light thus fluctuates 100 times per second in the brightness. However, the human eye is far too slow to perceive these rapid changes in brightness. Uniform brightness impression is created.
In order to reduce this brightness impression, the complete half-waves must no longer be fed to the lamp. Part of the half-shaft must be cut away.
At an effective value of 230 V, the peak voltage is 325 V.
Electronically truncated
If nothing is cut off from the sine wave, the lamp lights up with full Leuchtkraft.
An electronic switch is integrated in a dimmer, which can switch quite quickly due to missing mechanical components. Triacs are particularly suitable for this task. Because they are inexpensive and can carry out a targeted switching process for every single half-wave of the AC line voltage. In practice, this means 100 on/off switching operations per second.
In addition, triacs can conduct the current in both directions. This means that the upper (positive) and lower (negative) half-waves of the lamp are used to generate light.
The light intensity of the connected illuminant can be illustrated with the area of the effective alternating voltage. If nothing is cut away from the sine wave, the full surface of the sine wave is effective and the illuminant generates the max. brightness.
There are two switching variants to cut away the unused part of the AC voltage:
Phase control dimmer
The first dimmers were phase angle dimmers. They were easy to set up, had quite a few components and worked perfectly with the then usual light bulbs (ohmic loads). You just had to make sure that the power of the connected bulbs didn't exceed the max. power of the dimmer. These dimmers were suitable even for inductive loads such as the block or toroidal transformers of low-voltage halogen systems.
Operation:
With the phase angle dimmer, the switch-on torque of the respective half-wave is shifted. After the AC voltage has passed through zero, the triac will lock and the lamp will not receive any current. Only when the switch-on pulse comes on, the triac switches on and at the output of the dimmer the voltage jumps to the current value of the alternating voltage. The triac remains conductive until the alternating voltage reaches the zero line again and the minimum holding current is undercut. The triac only switches on again at the next switch-on pulse.
Control:
The brightness of the lamp can be controlled by shifting the switch-on time. If the time is moved to the right, the lamp becomes darker. If the time is moved to the left, the lamp becomes Heller.
Trailing edge dimmer
A dimmer, which works with incandescent lamps for years without interference, will cause problems with a new low-voltage halogen lamp with safety-keeping. The fault is the electronic halogen transformer. This represents a capacitive load, which causes a high current consumption when switched on abruptly. For this reason, the voltage must rise "gently" for capacitive loads. An abrupt switch-off, on the other hand, is possible without any problem.
Operation:
In the case of the phase section dimmer, the switch-off torque of the respective half-wave is shifted. Power MOSFET transistors or IGBTs are used as electronic switches. After zero continuity, the AC voltage at the dimmer output increases "softly". The output voltage corresponds to the input voltage at this moment. However, if the switch-off pulse comes on, the dimmer switches off the voltage abruptly. The lamp no longer receives any current from this moment. It is only switched on "softly" again at the next zero-run.
Control:
The brightness of the lamp can be controlled by shifting the switch-off time. If the time is moved to the right, the lamp becomes Heller. If the time is moved to the left, the lamp becomes darker.
Note:
In the course of the technical development phase angle dimmers are now also equipped with power MOSFET transistors or IGBTs. Even if this means that the technical effort is considerably greater and the price is slightly higher. Together with a more clever control electronics, the application area of these dimmers is then considerably increased. This allows you to dim far more different illuminants.
Which dimmer fits which bulbs?
At times when light bulbs were used for lighting, you definitely didn't have to worry about whether the dimmer fits the light bulb.
However, there is now an almost unmanageable variety of different illuminants. In addition to the high and low voltage halogen lamps, fluorescent tubes and energy-saving lamps, LED bulbs are gaining more and more market share.
Unfortunately, not all of these bulbs can be dimmed without restriction. Especially with LED lamps, the effect occurs that due to the low power consumption they do not reach the minimum load required by many dimmers.
In order to quickly find the right dimmer, the manufacturers mark their dimmers with a horizontal triangle and three letters:
Letters indicate for which lights the dimmer is suitable.
Letter R: This letter stands for Ohm's loads. These include light bulbs or high-voltage halogen lamps. Instead of this marking, a circle with an X is also often used as a light bulb symbol. As a rule, these dimmers are phase angle dimmers.
Letter L: This letter stands for inductive loads. Inductive loads include conventional halogen transformers in wound design such as block or toroidal transformers. However, 230 V electric motors can also be controlled if the power consumption of the motor does not exceed the max. dimmer power. These dimmers are usually phase angle dimmers.
Letter C: This letter stands for capacitive loads, such as electronic halogen transformers or electronic ballasts. LED lamps can also be operated with these dimmers if the LED bulbs are explicitly marked as dimmable. These dimmers are usually phase-section dimmers.
Practical advice
If you have an older dimmer in your hands that does not have an identification letter printed on it, you can use the power rating to perform a classification. If the power is specified in watts (W), the dimmer is only suitable for resistive loads (R). If the output is specified in VA (Volt Ampere), the dimmer is suitable not only for ohmic loads but also for inductive loads (L) such as conventional transformers.
Dimmable LED-lamp
Meanwhile, the light bulb manufacturers are also classifying your products better and better.
A quick look at the packaging is enough and the customer can see at first glance whether the respective illuminant is dimmable or not.
What types of dimmers are there?
Dimmers for the residential and business areas are available in various forms and forms. They are either permanently installed in lights, can be installed in switch boxes or in installation distributors. For mobile lamps, cord dimmers are very much used, which are integrated directly into the connection cable.
The following overview describes the most important and most frequently used dimmer types and helps you to find the right dimmer.
Universal dimmer
This type of dimmer is one of the most smart dimmer versions, which can be installed relatively easily. Almost all charging starts can be dimmed with a device of this type. These dimmers automatically measure the characteristics of the connected load when used. Then use the appropriate dimming principle.
Rotary and touch dimmer
These two types of dimmers differ according to the type of operation. With a rotary dimmer, you can adjust the brightness of ceiling lamps, spots or other lights continuously by means of a rotary knob. Press the rotary dimmer to switch the lighting on or off.
With a touch dimmer, you find a kind of rocker as a switch, which can be operated in two different ways. By pressing the button down or upwards, you increase or decrease the intensity of the lighting. A short press of a button switches the light on or off completely.
Surface-mounted and flush-mounted dimmer
These terms distinguish the way they are installed. Flush-mounted dimmers are, as the name suggests, hidden in a so-called flush-mounted socket with the electrical installation for the switch under the wall's plaster. A surface-mounted dimmer, on the other hand, is not sunk into the wall, but can be simply attached to the wall.
DIN rail dimmer
This designation depends on the type of installation of the dimmer. DIN rail dimmers are mounted in fuse boxes, sub-distributions or housing boxes on mounting rails. A DIN rail or DIN rail is a metal rail on which different electrical equipment such as miniature circuit breakers are mounted. The association with a hat is derived from the shape of the mounting rail.
Pull Dimmers
In contrast to permanently installed dimmers, which are either in the wall, the socket or the illuminant itself, these practical, small devices can be built "in between". A combination of plug and socket is inserted in front of the lamp to be dimmed, while the continuous dimmer function is controlled via a switch on a cord. These models are ideal for easy combination with floor lamps and side lamps.
What should you pay attention to when buying dimmers?
Most energy saving lamps are not dimmable.
Before purchasing a dimmer, you should check whether your lamp can be dimmed.
Dimming is usually not possible with energy-saving lamps and conventional fluorescent tubes are not suitable for combination with a dimmer.
Normal light bulbs can be dimmed without any problem, however, due to the legislation, light bulbs are increasingly being replaced by modern light bulbs. All halogen lamps, on the other hand, can be dimmed without any problems, was also beneficial for their energy consumption.
LED bulbs are available as dimmable versions, whereby the dimmer must also be suitable for LED bulbs.
Another important point in dimmer selection is the max. connection power. The current flowing through the electronic switches in the dimmers is limited by the design. Therefore, the power of the connected illuminants must not be greater than the max. connection power of the dimmer. As dimmers always require a certain minimum load, the manufacturers always specify a performance range. Especially with LED bulbs, it is possible that the minimum load of the dimmer is not reached and therefore the brightness cannot be controlled.
If the dimmer has to be integrated into an existing switch range, it is often the better solution from the manufacturer of the light switch/socket also to obtain the suitable dimmer. This ensures that the dimmer, switch and socket are perfectly harmonized with each other.
The most common questions about dimmers
How can ich dim LEDs?
Access dimmable LED lights, which you can then combine with suitable dimmers for LEDs. If individual components are not coordinated, you risk that the dimmer will not cope with the low current and that the LED in the LED lights will not light at all.
Can ich install dimmer myself?
If a defective dimmer needs to be replaced, this will be a major interference in the electrical installation. The intervention must only be carried out by specialists who are familiar with the necessary expertise. Important safety rules, such as unlocking, securing against switching on again and determining that there is no voltage must be taken into account. If you are not familiar with the required procedures or do not have the necessary measuring options, you should ask a specialist for help.
How do ich know if a transformer is electronic or conventional?
Conventional transformers have two copper wire windings and an iron core. Therefore, they are quite heavy in terms of their size. The design corresponds to a cube or a cylinder. Electronic transformers, on the other hand, are much smaller and housed in a flat housing. Due to the high clock frequency, much less copper wire and iron is needed, which makes the transformer very light. Measuring the output voltage is only meaningful with an oscilloscope, since multimeters often display incorrect or no measured values in electronic transformers.