Mains Transformers Mains

Transformers to convert a mains voltage of 230 V to a more suitable voltage for the appliance you want to use. The transformer is installed directly in the device itself, for example in an external mains supply or in a control cabinet. For industrial applications, there are transformers that can be used at an input voltage of 400 V or more. The choice of a suitable transformer does not only depend on the primary and secondary voltage, but also on the power. For a 12 V mains supply with a maximum of 3 amps, the transformer can be selected according to the following formula: 12 V x 3 A = 36 VA x factor 1.4 = 50 VA. Due to the factor of 1.4 that is used, the mains transformer is loaded a maximum of 70%. Overloading is thus almost impossible to even with sustained maximum load.

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 Safety transformers

Safety transformers meet special safety requirements and are subject to strict conditions. Due to internal protection measures such as reinforced insulation, these transformers have a high short-circuit resistance. This ensures that there is no electrical connection between the primary and secondary coils during a fault. In addition, safety transformers are often equipped with safety devices or fuses.

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Control

transformers Control transformers are used in energy and automation technology. These transformers provide a reliable power supply to control and auxiliary circuits. Thanks to additional branches, it is possible to adapt the local power supply. In the event of a fault, the short-circuit current in the circuit is limited and the fault from switching inductive loads is reduced.

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 Compact power

transformers These transformers can do a little more than conventional main transformers. In addition to the transformer, there is also a rectifier and a capacitor in the housing. This ensures that compact power transformers do not supply AC voltage, but DC voltage. In compact power transformers, several AC voltage connections are routed to the outside. This makes these transformers (see picture) ideal for experimenting with. The user decides whether to use the internal rectifier and capacitor.

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Printed transformers Printed

or printed circuit board transformers are preferably used as mains transformers for small devices that do not have a high energy requirement. The transformer is built into a plastic housing and has vertically running connections. This makes them extremely suitable for mounting on a printed circuit board. Smaller PCB transformers have strong solder joints to give the transformer sufficient stability. Larger PCB transformers have tabs that can be screwed onto the PCB. When choosing the right print transformer, you also look at other factors, such as the primary and secondary voltage, the power and the distance between the connections.

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Halogen transformer

In the past, these transformers were used to power low voltage halogen lamps. They were designed as physical transformers with primary and secondary windings which made them cumbersome and expensive. Halogen transformers are now offered as electronic transformers. These are much more manageable and take up less space. If halogen lamps are replaced by LED lamps, some electronic transformers may malfunction. This is because the lower operating current of an LED lamp does not reach the minimum load required by the transformer.

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Toroidal transformers

The round design of this toroidal transformer offers advantages, but it does come with a price. The round model provides a better efficiency than regular transformers. The magnetic field is significantly less present. For this reason, toroidal transformers are often used in sound installations. Further advantages are the compact dimensions, the lower weight and the low noise produced by the transformer. High-quality toroidal transformers always have an inrush current limiter in the form of a PTC.

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Ballast transformers

Ballast transformers are used to adapt voltages, for example in devices designed for the American mains (110 V/60 Hz), but which have to function temporarily on the European mains (230 V/50 Hz). Ballast transformers only change the voltage, but not the mains frequency. However, this is not important in most applications. Because ballast transformers can be used individually, there is the possibility with some devices to set both the output and input voltage.

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Control transformers

A control transformer allows individual output voltages. This transformer is mainly used in measurement and control technology, in laboratories and in automation technology. Using a control transformer, different output voltages are generated at an input voltage of 230 V/50 Hz. You can adjust the output voltage by turning the knob. This is a rotating contact on an annular transformer coil. Stabilizing voltage fluctuations of, for example, your television becomes very easy! The transformers are also designed as autotransformers with only one winding and without galvanic isolation or as separate control current transformers with two windings.

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Energy

saving transformers Energy-saving transformers usually consist of a coil with one or more taps for the output voltage. These transformers are preferably used when the input and output voltages are very close to each other in terms of values. This is because an autotransformer only transforms the voltage difference between the input and output. There is no electrical isolation between the input and output voltage in an autotransformer, and they also have only a single winding.

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Laboratory

isolation transformers These transformers are used for development, service or repair work on electronic circuits. To avoid electric shock, the circuit being worked on must be isolated from the mains voltage. This galvanic isolation is achieved via an isolation transformer to which the device to be repaired is connected. Isolation transformers have a fixed output voltage or it can be set individually. With individual control, a variable isolation transformer is preached. Due to the galvanic isolation of the voltage network, isolation transformers have no protective contact at the output.

Important: The isolation transformer must always have higher power than the connected device.

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PA transformers, PA transducers

PA transformers can be used to connect several loudspeakers together. This is useful in places where the audio needs to be amplified, such as in public areas. A PA transformer, with the same values ​​as the loudspeaker used, is connected to the input (the primary side) of the amplifier. The secondary side of the PA transformer converts the audio signals (100 V). The loudspeakers (L1-L4) also use a PA transformer, which resets the high impulses on the 100V line to a voltage compatible with the loudspeaker. Multiple PA transformers with associated speakers can be connected to a 100 V cable without any problems. This makes it easy to bridge longer cable distances.

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Transformers Audio

In audio transformers are more concerned with the quality of the signal than the performance. Initially, they mainly function as transformers but do not need to transform large capacities for this. Instead, these transformers ensure the highest possible quality in microphones, for example. Due to the galvanic isolation, the amplifier and microphone circuits do not come into contact with each other. Audio transformers are also used in mains power, in High Frequency or digital technology. In these techniques, it is called a pulse transformer, which requires less broadband in terms of transmission frequency.