DE719744C - Circuit arrangement in which a relay is switched on when a current surge is received by the discharge current of a capacitor and only drops out again when a second current surge is received - Google Patents

Description

Circuit arrangement in which a relay when receiving a current surge is switched on by the discharge current of a capacitor and only when it is received of a second current impulse drops again. In electrical engineering, especially in the In the field of remote switching, the task of switching a relay through current surges often occurs to operate. For this purpose, circuit arrangements have been developed in which upon reception of a current surge, a relay is switched on by the discharge current of a capacitor and only drops again when a second current surge is received, but these arrangements usually have a very complex and special design.

Such is a circuit arrangement of the mode of operation set out above became known, in which an auxiliary relay is briefly switched on by each current surge connecting a charged capacitor to the relay coil, the Brings the relay to the pickup and moves over the relay coil until the relay drops out discharges. As a relay is a special one, namely one with a pull-in and holding coil, selected, and a switching device for the capacitor is also necessary, which is charged with different polarity for switching on and off. The known arrangement is therefore quite cumbersome, because it requires besides the two coils for the relay no less than two changeover and one normally open contact. In addition, the polarity reversal of the capacitor is noticeable every time, because when the relay responds, the capacitor is not always fully discharged and then the charge still sitting on the capacitor after reversing the polarity of the charging current is opposite and a fast and complete charging of the capacitor prevented.

On the other hand, it is known to have a high resistance with a Power source constantly connected through the capacitor circuit Sinaßnahine to be discharged via a response, winding of the control relay and after the control relay has responded via a changeover contact of the control relay to be connected to a reverse winding of the control relay, so that when the Switching action by the discharge current of the capacitor flowing through the counter winding the excitation of the holding winding of the control relay is compensated.

Instead of the two equal, opposing, acting windings of the In another known arrangement, the relay becomes the pick-up winding of the control relay reversed polarity after you tightened, so that the pick-up winding is also the opposite winding is used for the holding winding. So either require the known arrangements in addition the holding winding has two opposing windings or a counter winding and two changeover contacts, which when the control contact is actuated again the Apply the winding to the opposite voltage so that the magnetization reverses. the relay is shed. The need to remagnetize the relay cores also offers the possibility of interference because demagnetization is not complete interfering with the next switching action, especially in the case of a rapid sequence -have to have an impact.

The invention offers a far easier and better way by they for a circuit arrangement in which a relay when receiving a current surge is switched on by the discharge current of a capacitor and only when it is received of a second current impulse drops again, suggests, with respective shutdown the entire arrangement from the local power source for the duration of the received Current surge causes the relay to respond by discharging a capacitor the only winding of the relay and its dropping out by completely discharging the im same sense charged capacitor in a duration less than the length of the received Current impulse lying time to cause and the switched on relay via a connect your own contact to your capacitor.

In this way the invention comes with a single coil and in In the most favorable case, only two working contacts are made, and no polarity reversal is required on capacitor or coil. Rather, the first power surge from a distance the charged capacitor is disconnected from the mains and connected to the relay, which immediately attracts and a bridging contact for the control contact between itself and the Capacitor closes. After the current impulse has ceased and the control contact has returned In its old position, the relay is directly connected to the mains voltage and the capacitor recharges immediately. At the second power surge, it only lasts a little longer takes longer than the first, the control contact is brought back to the position that he disconnects the capacitor from the network and places it on the relay coil. The condenser then discharges to below the holding voltage of the relay, which drops out The bridging contact opens and the basic setting is restored.

In order not to be tied to the time when administering the stroke are to your remote controlled relay working with the capacitor Resistors connected in series or in parallel, which correspond to the required duration of the Regulate power surge.

According to a further feature of the invention, the resistance at Attracting the relay cooperating with the capacitor through a contact of the same to be switched on.

The features of the invention are illustrated by the embodiments of Illustrations explained.

In the circuit of Fig. I, i is a pulse controlled Intermediate relay, e.g. the actual actuating relay, both of which are common Can be of construction. The relay i, which is preferably on weak, through the trunk line transmitted currents responds, you will press switch 3 for the duration the generated current surge to attract. The relay i has one Changeover contact i i, which when relay i responds from position i i " is thrown into position l lh. This makes the energy store .1., A capacitor, which until then had been connected to a local power source, from the power source switched off and applied to actuating relay 2. The voltage of the memory 4. and the stored energy are sufficient to energize relay 2 bring and hold for a while. At the moment the suit takes place an automatic Bridging of the contact l lh by the own contact 2l of the relay 2 instead of, so that when the power surge transmitted over the trunk line ceases, even after dropping of the relay i and the reset of the contact i i in the position i iu the relay 2 remains attracted. This relay now receives its current via the contacts i i "and 2z. The memory d. is immediately recharged on the occasion. If the relay 2 is to be made to drop out again, there is another current surge required via the long-distance line by pressing button 3. The relay i pulls in this If on again, the contact i i puts out of position i i, after i ib um, so that the relay 2 again draws its current from the memory. If the current surge and thus the mentioned switching position lasts long enough, then the memory 4 discharged so far that the relay 2 comes to waste. The relay breaks thereby its own contact 21. If the remotely transmitted current impulse stops, so the contact i i goes back to its original position without affecting the position of relay 2 changes something, because its circuit was through the contact 2 z has already been opened. The memory 4, however, is immediately in this case too recharged as soon as the contact i i returned to the iia position.

The conditions are shown in Fig. 2 on the basis of the discharge curve of the capacitor still shown graphically. Curve E represents the voltage curve of the capacitor 4 as a function of the time. At the time o may the .Kondensator the voltage E, which corresponds to that of the power source. Is he now from the Power source - switched off and applied to relay 2, the discharge takes place accordingly the curve E instead. Within the relatively short time t, may the relay Tighten 2, the capacitor voltage will then only slightly, up to the value Ei, have sunk. Is now about the point E. after time t2, release button 3 and the relay i is brought to drop, so in the circuit according to Fig. i the voltage of the capacitor and the relay 2 lying parallel to it again up to the value of the mains voltage E, and remain in this position for the time being.

If the current surge occurs again, the discharge process begins as a result of switching off the mains supply again, again at voltage E, along the curve E. If the current surge lasts long enough, the moment ts is finally reached, at which the voltage of the capacitor has dropped to the value E3, at which relay 2 drops out. If after a time equal to or longer than t3, der-Impulse contact 3 is opened again, this causes the capacitor 4 of Fig. i is connected to the mains voltage again, so it immediately takes the voltage value again E, while the relay 2 itself is completely dead and remains dropped.

As you can see from Fig. 2, it is with the circuit after Fig, i required to use a current surge to operate the relay 2, the is at least equal to t1 and at most equal to t3, while the reverse actuation of the Current impulses last longer than t3.

To this disadvantage, the certain of the operator's sense of time Makes demands and, taken in absolute terms, relatively long operating times requires to avoid, a resistor 5 can be in the power supply as shown in Fig. 3 which has the effect that the relay does not have full voltage after it has been activated, but approximately assumes the value E4, see the curve in Fig. 2. With these conditions the network is separated by the contact i i when a current surge occurs, see above the discharge begins at the relatively low voltage value - E4 and causes the relay to drop out after a time t3 minus t4. E4 becomes one expediently only 'so much higher than choose what by appropriate dimensioning of resistance 5 can happen; that for switching on and switching off on current impulse of the same length or pressing button 3 is sufficient.

Mind you, it charges after switching it off and pressing it back of the contact i i in the position i ia the capacitor 4 to the full mains voltage E, so that for switching on relay 2, the discharge curve of the capacitor 4 at the Metz voltage E, begins. The necessary current surge duration is therefore for switching on again between the limits t1 and t3. The same or almost the same however, the same time limits can also be set for the switch-off process, since the value t04 is also quite small when the series resistor 5 is present can be measured.

The circuit according to Fig. 3 can also be improved. she owns namely the certain disadvantage that for the charging of the capacitor 4 'by the Resistance 5- a delay occurs. In many cases this will be delay do not matter, in the other cases, e.g. B. with rapidly successive Actuations and reverse operations can be avoided by short-circuiting the Resistance 5 depending on the position of the relay 2, each time the relay has dropped out. The capacitor is then no longer charged via the resistor 5, but directly via a contact connected in parallel 22 (Fig. 4).

By the way, instead of a series resistor 5, as shown in Fig. 5 use a parallel resistor 6 to relay 2. This then has the effect that when the relay is switched off, the discharge curve no longer follows the course E in the Fig. 2, but the dashed course after the curve E 'takes. Here is the dropout voltage E3 already reached after a time ti which is approximately corresponds to that required by the relay to be energized. Generally will you probably prefer the circuit according to Fig. 3 and 4, because with these circuits the Power consumption by the resistor 5 can be reduced considerably while it is increased by the resistor 6 in Fig. 5 compared to the pure relay current.

Fig. 6 shows another one that has the same effect as that of Fig. 4 Circuit in which the contacts 21 and 22 (Fig.4) form a single changeover contact 21 are united. In the fallen state, as shown in the figure, the Capacitor 4 is connected directly to the mains voltage via contact zza and * 2111. If the contact z z in the position r ib shifted, the relay 2 receives voltage via the contacts rib and Zia from capacitor 4, attracts and is self-contained via the self-contact erb directly to the capacitor 4. When the contact z i is actuated back, continuous supply takes place of the relay 2 via the contact i r a, the series resistor 5 and the self-contact give. The mains voltage is divided in the ratio of the resistors 5 and 2 as in Fig. 3, where the partial voltage applied to the relay: 2 is also the Capacitor voltage is. If the contact zr is re-entered for the purpose of re-actuation Position rzb brought, the discharge of the capacitor 4 takes place from the low partial voltage, so that the dropout voltage of the relay 2 according to is reached in a short time. When the impulse stops and contact returns r i in the position z r11 then the relay 2 that has become de-energized remains in the de-energized Position, while the capacitor immediately goes back to i i, and 21, to full Mains voltage is charged and is ready for a new actuation of relay 2.

Claims (4)

PATENT CLAIMS: i. Circuit arrangement in which a relay is received upon receipt a current surge is switched on by the discharge current of a capacitor and only drops again when a second current surge is received, characterized in that that with the respective disconnection of the entire arrangement from the local power source the response of the relay (2) by the for the duration of the received current surge Discharge of a capacitor (4) across the only winding of the relay and its dropping out by completely discharging the capacitor (4) charged in the same sense in one in duration less than the length of the received rush current is caused and that the switched on relay (2) has its own contact (2z) with the capacitor connected is. 2. Circuit arrangement according to claim i, characterized in that to the relay (2) resistors (5, 6) are connected in series or in parallel, which regulate the required duration of the current surge. 3. Circuit arrangement according to the Claims i and 2, characterized in that the capacitor (4) has a contact (i i) of a relay (i) is connected to the network and when it is disconnected from the network by a contact this relay (r) is applied to the relay (2) to be reversed, its own contact (2i) a current path to the network prepared and approximately for the duration of the capacitor effect on the relay (2) maintains. 4. Circuit arrangement according to claims i to 3, characterized in that the resistor (5) when the relay (2) is pulled is switched on by a contact (22) of the same.