DE967015C - Arrangement for returning the movable system of a timer or milliampere second relay, preferably intended for X-ray equipment - Google Patents

Description

ISSUED SEPTEMBER 26, 1957

K2Il82VIIIb / 2IC

In the one that has become known in particular for X-ray systems Milliamperesecond relays and also time switches, which after reaching a previously set mAs product or after a previously set time (exposure time) has elapsed Trigger switching process, e.g. B. switch off the X-ray tube and thus end the X-ray exposure, becomes the moving system of the time switch or mAs relay by means of a current-flowing coil brought back to the starting days. Most of the time there is a special one to bring back the moving system Coil provided; but you can also use the coil, which during the course of the Time switch or mAs relay from the working current, so z. B. the X-ray tube current or a proportional current is flowing through it, use by passing a current through the coil in the opposite sense of direction (direct current of opposite polarity). To the Returning takes a certain amount of time, i. i.e. the next sequence - the timer or mAs relay can only take place after the time required for the elevator. In many cases this is Time too long. So z. B. in the so-called functional diagnostics a recording frequency of requires five to ten x-rays per second at a maximum of about 50 mAs. The one to lead back the moving system's time

709 691/15

but is ζ. B. in the working on the moving coil principle known mAs relay, if the recordings can be done with about 5omAs, about ο, 16 seconds. So it is too big because it is about 40 ms would have to be. One might think of shortening the elevator time by sends a higher current through the winding coil; But that would mean that the coil 'must be made with a larger wire size so that it can withstand this higher load. This way is usually, especially with mAs relays for X-ray systems not feasible, because then the weight and dimensions of the movable one System would get too big.

The invention proposes a different, conveniently feasible solution to the stated problem before. According to the invention, the return time (elevator time) by during the return of the moving system takes place briefly increasing the current flowing through the coil shortened to a value that the coil briefly, but not permanently, four-folds. Particularly beneficial it is, if by means of a delay relay, its expiry at the same time as it is switched on the winding spool begins, the duration of the flow of the increased elevator current is automatically limited will. So you can with the arrangement according to the invention, the winding spool with the to achieve low weight and small dimensions of the movable system required Execute wire size · and still achieve a sufficient shortening of the winding time because the coil can only tolerate a short-term increase in current. In Figs. 1 and 2 are two embodiments for an arrangement according to the invention shown in circuitry, all for understanding Parts not necessary for the invention are not drawn in. At 11 is the winding spool of a mAs relay, as it is used in X-ray systems, denotes; she is at one DC voltage source 12 through switches 13, 14 can be connected, which can be operated, for example, by a contactor 15 which, after the mAs relay has expired, so after completion of the X-ray exposure, is excited and the switches 13, 14 in the illustrated Position. The elevator spool 11 is a resistor 16 upstream, the current flowing through the coil to the continuously permissible level limited. Through the contact 17 of a delay relay 18, the resistor 16 can be a smaller one Resistor 19 can be connected in parallel. In this case, with the contact 17 closed, increased as a result of a reduction in the upstream resistance of the one flowing through the winding reel 11 Current to a value that can be tolerated by the coil for a short time, but is sufficient to to shorten the elevator time sufficiently. In the excitation circuit of the delay relay 18 is a switch 20, which in Fig. 1 simultaneously with the switches 13, 14 when energizing the contactor. 15 closed will. When the delay relay 18 is de-energized, the contact 17 is closed. By doing Moment in which the winding coil through the contactor 15 Ii is connected to voltage, the delay relay 18 is also connected to the auxiliary voltage source 12 connected. Since the contact 17 only is opened after a certain, adjustable time by the delay relay 18, initially flows through the winding reel 11 for a short time long the increased elevator current. As soon as the contact 17 after. Expiry of the set delay time is opened, -decreases through the coil 11 flowing current to the permanently permissible value, which is conditioned by the size of the resistor 16 is.

In the embodiment shown in Fig. 2, the delay relay 18 is switched so that that it is when the winding reel 11 is not on Voltage is present, the switches 13, 14 are therefore open, excited via the switch 20 which is then closed is and accordingly the contact 17 is closed. Is now by the contactor 15 the Coil 11 is connected to voltage, so flows through the parallel connected resistors 16, 19 of the increased Current through the coil 11 until the contact 17 of the delay relay 18 opens. Because the relay 18 is at the moment of connection the coil 11 to voltage · by opening of the switch 20 is de-energized and opens after the specific 'set delay time has elapsed its contact 17, so that now the continuously permissible current flows through the coil 11. This execution form has the advantage over that shown in Fig. 1 that in the event of failure or Failure of the delay relay 18 does not allow the increased current to flow continuously through the elevator coil 11 and destroy or damage them.

In both exemplary embodiments, the resistor 19, which can be switched in parallel, can be omitted if a part of the resistor 16 can be short-circuited through the contact 17. In the way it works nothing changes in the two arrangements. The delay time of the relay 18 can by connecting a capacitor in parallel or by arranging short-circuit windings can be changed, if necessary adjusted as required. The arrangement according to the invention can also be made to disable the delay relay can, so that either with or without a brief increase in the elevator current, the movable System of the mAs relay (or the time switch J can be returned to the initial position X-ray systems, for example, this arrangement is advantageous insofar as normal images, which do not follow one another particularly quickly, only with the low elevator current and only when a high recording frequency is required, with a brief increase in the Elevator current can work.

A shortening of the winding time can also be achieved by the fact that the coil, which is to return of the moving system in the starting position, by means of a capacitor charging correspondingly strong current pulse is given. This arrangement has, however, compared to the one above

Hand of Fig. Ι and 2 described arrangement with a delay relay the disadvantage that the Capacitors must be made relatively large and that they take too long to charge lasts, whereby the gain in shortening the elevator time would be nullified again, it was because, special measures are taken to shorten the loading time.

The arrangement according to the invention is advantageous for all mAs relays or time switches in which a current-carrying coil causes a thrust or rotary movement of the moving system, whose path forms a measure for the mAs value or time value reached in each case, and for which the The system is returned to its original position by a countercurrent that flows through a longer period of time flows through a corresponding coil and its permissible size does not meet the short-term elevator condition fulfilled for the whole way or part of this way.

Claims (7)

Patent claims: 1. Arrangement for returning the moving borrowed System of a timer or preferably intended for X-ray devices Milliamperesecond relay in its starting position by means of a current-carrying coil, thereby characterized in that occurring during the return of the movable system short-term increase in the amount flowing through the coil. Current to a value that the Coil can be tolerated briefly but not continuously, the return time (winding time) can be shortened is. 2. Arrangement according to claim 1, characterized in that that by a delay relay, which expires at the same time as it is switched on the elevator reel begins, the duration of the flow of the increased elevator current automatically is limited. 3. Arrangement according to claim 2, characterized in that that in the circuit of the winding reel there is a resistance that the The current flowing through the coil is limited to the permissible level and by the delay relay can be reduced to a value corresponding to the increased elevator torque. 4. Arrangement according to claim 3, characterized in that deir resistance from one permanently in the circuit of the elevator coil and a part due to the delay relay part that can be switched in parallel. 5. Arrangement according to claim 3 or 4, characterized in that the delay relay voltage is applied at the same time as the winding coil and after the set time has elapsed Delay time of the resistor connected upstream of the winding coil by opening its Contact is increased to the value that corresponds to the permanently permissible elevator current. 6. Arrangement according to claim 3 or 4, characterized in that simultaneously with the Switching on the elevator coil the previously closed circuit of the delay relay opened and by its contact after the set delay time of the elevator coil upstream resistance is increased to the value that corresponds to the permanently permissible elevator current. 7 " 7. Arrangement according to claim 2 or one of the following claims, characterized in that that the delay relay is inoperative, so that either with or without brief increase of the elevator current the moving system of the timer or mAs relay can be returned to the starting position. Considered publications:
German patent specifications No. 666 126, 737 500. 1 sheet of drawings © 509565/105 9.55 (709 691/15 9.57)