FR2486278A1 - TORQUE OF PHOTOELECTRIC CELLS WITH INFRARED RAYS, IN PARTICULAR FOR THE CONTROL OF A POWER ELEMENT - Google Patents

Abstract

THE COUPLE OF INFRARED-BAY PHOTOELECTRIC CELLS INCLUDES AN EMITTING PHOTOELECTRIC CELL 1 INCLUDING A LIGHT PULSES GENERATOR 4 WITH A HIGH RELATION BETWEEN THE EMISSION TIME AND THE PAUSE TIME OF THE PULSES, AND A MULTI-ELECTRIC PHOTOELECTOR 2 COMPORTANT CELL 2 CAN BE DRIVEN BY VERY SHORT TERM PULSES AND DESIGNED TO RECOGNIZE THE CODE OF PROJECTED LIGHT AND TRANSFORM THE PULSES INTO A SQUARE SIGNAL, CAPABLE OF DRIVING A RELAY OR ANOTHER POWER ELEMENT. THE INVENTION APPLIES IN PARTICULAR TO THE CONTROL OF ANY RELAY, STATIC OR ELECTROMAGNETIC.

Description

The invention relates to a pair of photoelectric cells

  infrared rays intended to control a certain relay

  conch, static or electromagnetic, for the intended use

  proprietary as a power control in general.

  With regard to photoelectric devices, light-modulated photocells are already known.

  generally using as a projector a laser diode,

  than always (though not necessarily) to infrared

  ges. The modulation of light is made necessary for

  prevent foreign lights from interfering

  tioning. The achievements of known type have the particularity

  to use continuous pulsed pulse

relatively low level.

  Currently, to have pulse projectors

  light of considerable power, it is necessary to have

  complex, cumbersome, expensive and inexpensive

high sorption.

  On the other hand, the object of the invention is to provide a

  number of photocells operating with a projection

  light pulses of very short duration but

  noticeable intensity (flash effects) while having a real erosive absorption equivalent, in order of magnitude, to that

  previously known photocells.

  This pulse regime, which would not be able to drive a relay, is made equal to the continuous regime in the receiver, comprising a monostable multivibrator driven by said pulses of very short duration and designed to transform into

  active time the pause time between successive pulses

are too distant.

  One embodiment of the invention will be described below.

  after, by way of non-limiting example, with reference to the appended drawings in which:

  FIG. 1 is a block diagram of the pair of

  FIGS. 2 and 3 show the pulse rate of the emitting photocell and the square signal at

  the output of the receiving photocell.

  In the drawings, it is generally indicated by the reference

  1 the transmitting photocell and by the reference

  2 the receiving photocell.

  The transmitting photocell 1 comprises a

  infrared ray jector 3 or laser diode, driven in rotation

  pulse generator 4 is provided with a pulse generator 4 supplied with 5. The pulse generator 4 is designed to emit pulses of very short duration (lightning) which are widely spaced in

  the time and appreciable power. The impulse chart

  For example, Figure 2 shows the duration of the pulses and their spacing.

in time.

  More specifically, if, for example, in a system of operation

  The normal frequency of the pulses is n

  According to the invention, pulse generator 4 emits 1 pulse in the same period of time. It follows that

  in the case under examination, the distance in time between two im-

  consecutive impulses will be equal to n - 1 while the duration of each impulse in time will be equal to the

  duration of each of the n pulses of a normal diet.

  It is understood anyway that, if it is not

  precisely 1, the frequency of the pulses emitted by the

  jector 3 may be any fraction of the frequency provided for the light-modulated photocell of

classic type.

  Regarding the power of the impulses of the

  jector, if one used for example a diode Siemens LD 242 to normal operation, one would have a power of 1.6 V x 200 mA = 0.32 W, whereas with the pulse rate here envisaged, one can get a power of 4.5 V x 4 A = 18 W, with all the benefits that come from it and that can not

to be obtained otherwise.

  For its part, the receiving photocell 2

  is intended to make a normal continuous

  impulses (not suitable for piloting a re-

  foreshore). For this purpose, the receiving photocell

  takes a sensor 6 designed to receive the light pulses

  from the projector 3 and to control, via

  amplifier 7, a monostable multivibrator 8.

  The latter can be controlled only by a pulse of very short duration which allows him, on the one hand, to recognize the code of the projected light and on the other hand, to transform

  all in a square signal of the type represented by FIG.

  In practice, the monostable multivibrator 8 is provided to reintegrate the "pause" time between two successive signals of the "active" pulse rate. Anyway, after

  amplification by means of amplifier 9 and

  tation, the square signal of the output of the multivibrator mo-

  nostable is able to drive a relay for proper use as a power control, as if the projection

  luminous was continuous or modulated in a classical way.

  It remains understood in any case that the values and

  The schemas listed above are provided only as e-

  xample because it is obvious that one can realize various

  the couple of photocells while maintaining

  before emitting light pulses (lightning) dk projector and the use of a monostable multivibrator

  in the receiver, with the aforesaid function of assimilating

  the pulse regime under normal modulated or continuous mode.

Claims (2)

R E V E N D I C A T I 0 N S   1 - Couple of photocells with infrared radii   red, characterized by a transmitting photocell 1   provided for the impulse projection of impulse   very short periods of time (lightning) very widely spaced in time but of great power and by a photocell   receiver 2 to assimilate this regime of im-   normal steady-state urges with reinstatement, in time   active, the pause time between the light pulses con-   and with acknowledgment of the pro- jetties.   2 - Couple of photocells according to the claim   1, characterized in that the photocell   transmitter 1-includes a light pulse generator   4 with a high ratio of transmission time to   pulses and that the photocell received   trice 2 includes a monostable multivibrator 8 that can be driven by very short pulses and designed to recognize the "code" of projected light and transform   the impulses into a square signal, capable of driving a re-   lais or other power element.