FR2699024A1 - Power triac with gate controlled by remotely switched light source - uses rectified very low current and voltage supply with series switch to power diode of opto-triac which determines gate voltage - Google Patents

Abstract

A pulsed transformer (1) has a bridge rectifier (2) connected to the secondary and the mains connected to the primary. The rectified supply is connected to the control switch (4) and the input diode of the opto-triac (3) which with the assistance of two series resistors (13, 14) controls the power triac (5). The transformer may be replaced by a series capacitor at each input terminal and a zener diode placed across the bridge rectifier. In another embodiment, a photocell is connected to the series switch across the diode of the opto-triac. The photocell is illuminated by a lamp or two banks of series LEDs with one back in parallel with the other and with opposite polarity. USE/ADVANTAGE - Domestic and commercial lighting. Uses control cable with lower current rating.

Description

RELAY STATIt) UX AUTONù
The present invention relates to an autonomous static relay for remotely switching any electrical appliance to an AC sector.

 Solid state relays are traditionally electronic modules that perform the switching in place of conventional mechanical or electromechanical switches. They are however dependent on an external source of low voltage current for their control. This current source generally comes from an independent power supply (ac / dc).

The device according to the invention overcomes the need for an external stabilized power supply or battery for the control current. I1 indeed comprises, and this is what characterizes it, a pulse transformer connected to the sector whose voltage it lowers and a rectifier bridge follows it. These two components alone make up the static relay control generator.

Given the very low voltage (less than 5V DC) and very low current (less than 20mA) of said generator, its interest is manifest in the context of very low safety voltages (Tws).

Another embodiment, always in the spirit of the autonomy of supply of the static relay, consists in replacing the pulse transformer by two capacitors (of which the reactance ### is exploited) followed by the same rectifier bridge. In this case, a zener diode limiting the direct voltage must be added to the output of the rectifier bridge.

One of the interests of the relay is to isolate the control circuit from the power circuit: anything that can improve this galvanic separation goes in the direction of better reliability and greater security.

Thus, according to a first particular embodiment, the pulse transformer or the capacitors of the cow; heath generator of the static relay can be replaced by a long-term incandescent lamp connected to the mains, associated with a photovoltaic cell.

 In this mode, said lamp also serves as an alternating voltage indicator light on the static relay.

according to a second particular embodiment, the incandescent lamp is replaced by two groups of light-emitting diodes mounted head to tail and also connected to the sector.

These two particular embodiments have the advantage of increasing the galvanic isolation between control and sector and of thus reinforcing
If the protection linked to very low safety voltages.

The particular embodiment using light emitting diodes is particularly suitable for optoelectronic integration.

The accompanying drawings illustrate the invention.

Figure i shows the electrical diagram of the device according to the invention. Zn reference to this figure I, the device comprises a pulse transformer (1) which supplies the sector and whose secondary is connected to a rectifier bridge (2), The outputs of this bridge (2) go to the diode d entry of an optotriac (o) via a switch (4). i in turn the optotriac outputs (3) control through the resistors (13 and 14) a power triac (5).

Thus, depending on the open or closed state of the switch (4), the optotriac (3) then the triac (5) are blocked or passing.

The phase input on the power triac (5) is done in Aw, its output in AI.

FIG. 2 represents the electrical diagram of a first variant of this device. Referring to this FIG. 2, the device comprises two capacitors (6 and 7) of the same capacity. This capacity is calculated using their reactance to obtain a very low voltage. Their insulation voltage is high to ensure perfect security since one of their frames is connected to the mains.

Their other two armatures go to a rectifier bridge (2) whose outputs are connected to a zener diode (9). At its terminals is connected the optotriac input diode (3) via the switch (4).

The rest of the assembly is identical to the previous Llintêret of this first variant is to allow the integration of the zone Z1 which becomes an integrated circuit. Thus the discrete components which do not dissipate heat are the subject of a new microelectronic chip (craps).

Figure 3 shows the electrical diagram of a second variant of this device. With reference to this FIG. 3, the device comprises a miniature long-term incandescent lamp (io) associated with a photovoltaic cell (him). This cell (tri) supplies the input diode of the optotriac (3) under the same conditions as the rectifier bridges (2) in FIGS. 1 and 2. The rest of the assembly is identical to the previous ones.

The advantage of this second variant is also to allow the integration of the zone Z. This time the photovoltaic cell (sorting) is part of the integrated circuit.

Figure 4 shows the electrical diagram of a third variant of this device. With reference to this FIG. 4, the device comprises two groups of light-emitting diodes (12). The light energy supplied by this set of diodes (12) is transmitted to the photovoltaic cell (11) .- The rest of the assembly is identical to others.

The advantage of this third variant is, similarly, of allowing the integration of the zone Z3- In this case all the discrete components, with the exception of the triac (5), are part of the new integrated circuit.

In practical terms, the autonomous static relay is produced either on a printed circuit, or molded in a block of epoxy resin. Its control and power connections lead to a terminal block. The assembly is adaptable on standard DIN rail.

The invention is particularly intended for lighting, incandescent or fluorescent, since it makes it possible to significantly reduce the power wiring which no longer goes through the switch. Zn ignition and extinction effect are made thanks to the weak current coming from the device Ce low current can run through fine wires to a traditional switch or a miniature low-voltage contactor that provides control.

Claims (4)

 1) Device for remote switching, by means of a triac (5) itself controlled by an optotriac (3), any electrical device on an alternating network, characterized by a very low energy in control current. This control current is supplied by a simplified power supply using a pulse transformer (î) whose very low voltage current is rectified by a rectifier bridge (2). 2) Device according to claim 1, and in a first variant, characterized by two capacitors (6 and 7) whose reactance makes it possible to obtain, from the network, a very low applied voltage. quée a bridge rectifier (2) which has its output limited in direct voltage by a zener diode (9). 3) Device according to claim 1, and in a second variant, characterized by a long-term incandescent lamp (ù) connected to the network, lighting a photovoltaic cell (11). 4) Device according to claim i, and in a third variant, characterized by two groups of light-emitting diodes (lwi mounted head to tail connected to the network, associated with a photovoltaic cell (11).