:: Toroid transformers ::

TORIVAC has over twenty years of experience in manufacturing all types of toroid transformers.

Toroid transformers represents, like no others, the ideal design for a transformer. In fact, Faraday designed and wound the first transformer on a toroidal core. The toroidal cores manufactured by TORIVAC are made of magnetic sheet metal with very low loss levels and high induction saturation, which when heat treated allow for reaching saturation values of up to 16,000 gauss. In the toroid transformer the magnetic flow is evenly spread in the core and due to the absence of intermediate metal parts, vibrations are eliminated.

Similarly, as all the wound coils are spread over the surface of the core, the noise caused by magnetostriction practically disappears, which favours the dissipation of heat. These features substantially improve the characteristics and yield of the toroid transformers with respect to conventional ones.

YIELD

Is the ratio between the output and the input power ratings and is variable depending on the size of the transformer and the working conditions, but which is almost always higher than that of conventional transformers of a similar power rating. The typical yield of our standard transformer, from 20VA to 3000VA varies between 82% and 96% (see diagram)

The yield of a toroid transformer is mainly conditioned by the resistive losses of the cooper wire and the losses in the core.

The former are optimised by using good quality sheet metal and sizing the wound coils appropriately. With regards to the losses through histeresis in the core, by means of an appropriate heat treatment, these are reduced to 0.98W/Kg, at an induction of 1.6T.

CONTROL WHEN LOADED

The control of a transformer is determined by the ratio between the secondary voltage, when empty and its voltage under the nominal load. The degree of control varies with the size of the transformer. At greater power ratings there is generally less resistance in the copper wires used in the wound coils and better control characteristics can be archieved.

The attached diagram reflects the increase in voltage when empty (%), with respect to the voltage at a nominal load, based on the power rating of the transformer.

RADIATION

The absence of intermediate metal parts in the construction of the core, its heat treatment, its painstaking design and the meticulous winding techniques used, allow for the achieving of very low magnetic dispersion, which is almost insignificant when compared with that generated by conventional transformers. When it is required that magnetic dispersion must be totally eliminated, one can add electromagnetic screens or shielding.

The application of the toroid transformers in the stages of power supply and power drawing is ideal as a good signal/noise ratio can be achieved.

ELECTROSTATIC SCREENS

The electrostatic screens are constructed using a copper layer winding coil, insulated with polyester, which completely covers the primary coil and has the function of filtering out the electrostatic interference from the mains power supply, when the voltage is transformed.

START UP TRANSIENT ELECTRIC CURRENTS

The toroid transformers usually have higher transient electric currents on starting up than conventional ones due to the absence of intermediate metal parts in the core, for this reason we recommend you to adequately protect the power supply with slowmelting fuses or timeout ones.

TEMPERATURE INCREASE

The working temperature of our toroid transformers varies, depending on the percentage load used, as can be seen in the attached diagram.

In the permanent working mode, these may increase between 55ºC and 60ºC, above the surrounding environmental temperature of the transformer does not display increases in excess of 45ºC.

SHAPE FACTOR

This types of transformers allow as no others to achieve low profiles and adapt the size to the dimensions called for in each application, adjusting the diameters and heights of the cores, due to the ease with wich their dimensions can be modified.


	POWER RATING: 15VA-750VA
	PRIMARY: 230V 50-60Hz
	SECONDARY: According to client specifications.
	INSULATION: > 3500V effective.
	YIELD: 82-93%
	TEMPERATURE: Máx. 55º C, above environmental temperature.
	PROTECTION: External. Use slow fuses.
	CONNECTION: Cables, terminals or pins for printed circuit.

TT SERIES (Standard to order)

This series is conceived for a 230V primary and a secondary of any voltage and power ratings between 20VA and 5,000VA, in accordance with the following table, but on order we can manufacture them to other voltages, adding screens, heat shielding, etc. The standard lenghts of the outputs are of 16 cm up to 500VA and 20 cm for 600 to 1000W and 25 cm for higher powers.

Depending on the number of secondaries, voltages screenings or protections, the size may be varied: and other minimum secondary voltages can be manufactured to order.

TT SERIES ( Standard in stock)

This series is conceived for a 230V primary and two identical secondaries, which allow for the duplication of voltages or intensities by connecting them serially or in parallel, in a range of power ratings between 20VA and 220VA. They are supplied with individual cardboard boxes and the assembly accessories.
The available models are as in the following table:

NOTE: Other voltages can be manufactured to order.

SERIAL CONNECTION: By briding yellow with white we will obtain twice the voltage between red and black at half the nominal intensity.

PARALLEL CONNECTION: By bridging red with white and yellow we will obtain twice the intensity and the nominal tensión.

Standard lenght of outputs, 20 cm.

TE SERIES (Resin packed)

These are transformers of the TT series, packed in epoxy resin, in casings of polyamide 6 which allow for the extension of the useful life and improve the insulation of the transformer, these are ideal for dusty and damp environments.

TCI SERIES (Packed for P.C.)

These are transformers of the TT series, packed in epoxy resin, in casings of polyamide 6 which are connected internally to the pins for their use directly on printed circuits. The raster between the pins is of 5mm and their number varies in accordance with the size of the casing. The connections can be custom configured in accordance with the requirements of each client.

The toroid transformers have numerous fields of application, and among these we can highlight as the most usual the following:

	Consumer electronics
	Medical electronics
	Converters
	Power supply systems
	Audio systems
	Security
	Telecommunications
	Low voltage lighting
	Any equipment that may require an optimal yield
	Etc...


	ELECTROSTATIC SCREENING.
	QUICK CONNECTION LEADS.
	HEAT SHIELDING.
	MATERIALS FOR HIGH TEMPERATURE CLASSES.
	ELECTROMAGNETIC SHIELDING.
	INTERNAL PACKING FOR MOUNTING SYSTEMS.
	PLACEMENT OF CONNECTORS AND TERMINALS.