FI66512C - SPAENNINGSREGULATOR FOER BELYSNINGSNAET SAERSKILT GATUBELYSNINGSREGULATOR - Google Patents

Description

1 66512 Voltage regulator for lighting networks, in particular street light regulator. - Spänningsregulator för belysningsnät, särskilt gatubelysningsregulator.

The invention relates to a voltage regulator for lighting networks, in particular a street light controller comprising an economy transformer connected between the phase line and the neutral line of the supply network, by means of which the power supply to the lighting network takes place.

For night periods when traffic is quieter, the light output of the street lights can be adjusted lower, resulting in significant energy savings while extending lamp life and replacement intervals. Controllers based on a saving transform and switching of the above-mentioned type are known. One of their disadvantages is that the control level remains relatively modest, because the sudden voltage drop cannot be very large without the risk of the lamps going out. To eliminate this, it has also been proposed to use adjustable saving transformers in which the mechanical sliding contact can be moved along the transformer windings. The disadvantage is the wear of the mechanical sliding contact, the consequent unreliability and the expensive cost. In addition, the winding wire of such a saving transformer must be dimensioned as a whole to the same thickness according to the maximum current, which substantially increases the price of the transformer.

The object of the invention is to provide an improved saving transformer and a control based on a circuit, which can be implemented with a structurally simple and inexpensive transformer and which provides a stepwise adjustment so that the intermediate stage prevents the lamps from going out.

This object is achieved by a controller according to the appended claim.

Next, an embodiment of the invention will be described with reference to the accompanying drawing, which shows the controller circuit according to the invention as a single-phase application. It is clear from 2,66512 that in multi-phase applications, a corresponding connection is made between each phase conductor and the neutral conductor.

The voltage of the phase conductor is, for example, 230 V. An economy transformer 1 with a two-part winding is connected between the phase conductor and the neutral conductor, the primary being formed by windings 2 and 3 and the secondary being formed by winding 3. The lamp load is connected between terminals 2 and 3 . Alongside the secondary winding 3 there is a switch k ^ with which the secondary winding 3 can be short-circuited. The outer end of the secondary winding 3 is connected on the one hand by a switch k-2 to the neutral conductor and on the other hand by a choke 4 to the phase conductor. The winding 2 has relatively few turns and is made of thick winding wire dimensioned for the main current. The secondary winding 3 has a relatively large number of turns and is made of a thin winding wire, because the currents passing through it remain considerably small in relation to the main current.

The operation of the controller is as follows. In the unregulated state, when a substantially unreduced mains voltage is desired for the lamp load, the switch k1 is closed and the switch k2 is open. In this case, the saving transformer operates in the same way as a current transformer, the secondary windings 3 of which are not loaded, but a current which is less than the main current passing through the lamp load can flow through the windings 2 and 3. In this case, the primary winding 2 of the (current transformer) does not act as a choke for the main current, and there is no significant voltage drop in the winding 2.

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The dimming control is started by opening the switch k1 · The choke 4 now switches on / off the load of the secondary winding 3 and its impedance is reflected in the converter winding 2, which acts as a choke. The voltage of the lamp load decreases from 230 V to, for example, 215 V. After a certain time, which is long enough to stabilize the state of the lamps, the switch k2 closes, whereby the saving transformer 1 becomes a normal saving transformer. A small current flows through the choke 4, but the inductive reactive power caused by it is negligible compared to the power saving achieved by the saving transformer connection. With a saving transformer connection, the voltage of the step load is, for example, 205 V. In this case, the energy savings to be achieved are more than 20%.

It is found that the switches k ^ and can be implemented with low current and cheap switches. This, together with the thin-wire secondary winding 3, makes it possible to build the controller at such a low cost that the payback time of the controller with the above-mentioned energy savings is very short.

In a practical implementation, several outlets can be arranged at the outer end of the secondary winding 3, to which the switch k ^ and the choke 4 can optionally be connected. The choke 4 can also be made adjustable for adjusting the intermediate stage voltage.

Claims (1)

Voltage regulator for lighting networks, in particular a street light regulator comprising a saving transformer (1) connected between the supply line phase line and the neutral line, by means of which the power supply to the lighting network takes place, characterized in that the first ^), by which the secondary winding (3) can be short-circuited and that the outer end of the secondary winding (3) is connected to the neutral conductor by a second switch (k2) and a phase conductor by a choke (4), the operation of the switches being arranged to be controlled closed and the second switch (k2) is open and that at the beginning of the dimming control the first switch (k2) opens and after a certain delay time the second switch (k2) closes.