DE604712C - Circuit arrangement for self-connection telephones, in particular for coin-operated telephones - Google Patents

Description

Circuit arrangement for self-connecting telephones, in particular for payphones The present invention relates to a circuit arrangement for self-connecting telephones where. for blocking and fee graduation different connections controlled by the dial: auxiliary contacts used especially for payphones. With the previous arrangements it was however, it is still possible to establish unauthorized connections through fraudulent measures.

For a better understanding, let us first refer to Fig. Z as the familiar Arrangement explained. In this illustration, those for the pay phone are otherwise necessary switching devices are omitted and only the contacts on the dial shown.

The reference symbols in Fig. R have the following meaning izsi is the pulse contact; f is an inertia contact that only opens as long as the dial is running. If, therefore, the dial is fraudulently prevented from running in order to trigger the connection by opening the pulse contact for a long time, the contact t closes. The mf contact is a coin feeler lever contact that closes when the dial is opened and no coins have been inserted into the device. The decade contact is designated by d, ie a contact which is actuated as a function of the number of series of current impulses sent. k is a contact that is moved depending on the digit selected.

It is now assumed that there are no high-speed calls from the payphone should be led. The number for the Schnellverkehrsamt is number 9.

Contact k should be turned over when an o or 9 is drawn will. So that now the switching of the contact k when pulling up a digit 9, if this digit is not in the first position of the phone number, remains ineffective, becomes the contact k after the first series of impulses has been emitted by the decade contact d bridged. The following fraud possibility now exists with this view arrangement The speaking guest first sets up the unauthorized connection by pulling up the number 9 ago. However, this connection does not come about because the contact k opens and the voters in office collapse by breaking the loop. now the speaker inserts a coin without first hanging up the receiver. The speaking guest pulls up the number g again. Contactd is closed and bridges the open contact k, so that. now reached the express traffic office will. Through the present invention, the outlined fraudulence becomes this prevents the auxiliary contacts from a magnet blocking the connection to attract, which is only caused by the resetting of the auxiliary contacts Hang up the handset can be brought to waste. This blocking magnet can simultaneously take on other functions in the pay phone; z. B. can through him the inserted coin can also be held in an intermediate layer until at a successful connection the cashier magnet has come into effect.

The invention is explained in detail on the basis of FIG which the following task is solved: From the pay phone, microphone units, such as fire brigade, robbery, can be reached free of charge without inserting a coin. The number of these departments is oi and o2. Connections with the Schnellverkehrsamt (Call number o9) and the remote office (call number oo), on the other hand, should be blocked. One Number of hand-held exchange B-places, which are identified by two-digit telephone numbers and whose first digit is not an o should only be reached after inserting a coin be. Also the call stations identified by a six-digit number In self-affiliation offices it is only possible to vote after inserting a coin. Such traffic relationships occur in large urban telephone networks such as Berlin, in which there are self-connection offices and hand offices at the same time.

The meaning of the individual reference symbols in Fig. 2 is as follows: The pulse contact zzsi and the number disk contactizsa of the number disk are shown. M is the microphone; F is the remote listener. The contacts HU, 2 HU and 3 HU are moved by the handset hook. The adjustment of these contacts is such that when the receiver is hung up, contact 2 HU is activated last. The auxiliary contacts on the dial, which are used to distinguish the connections, are marked a, d and o. -The contact a should be closed when a number is dialed whose first digit is an o and whose second digit is an 8, 9 or o. Contact d is transferred depending on the number of digits dialed. In the present case, it should be actuated when the dial is opened the third time. The contact o is opened when an o is selected. The contacts a, d and o are brought back to their initial position by hanging up the receiver. Contact 1 is an inertia contact that closes as soon as the dial is inhibited in its sequence. A coin sensor lever contact is designated with znt, which is closed as soon as the dial is opened and no coin has been inserted into the device beforehand. 1 (M is the cashier's magnet, through which the coin is transported into the cashier's container. Sp is the blocking magnet which, when energized, blocks the coin from flowing into the return container. The blocking magnet Sp has two windings Sp I and Sp II. The resistance of the winding Sp II should be very high. W is an alarm clock; Wi is a resistor; C is a capacitor. Of the switching devices in the office, only part of the group selector is indicated schematically. A is the control relay of the group selector. B is the well-known relay that is used to suppress counting when the trunk is disconnected.

Depending on the message from the called subscriber, in As is known, a relay Z which comes into effect when the connection is triggered excited, of which only the contact z is shown.

The mode of operation of the circuit is as follows. Assuming the speaking guest tries an unauthorized connection, e.g. B. to establish a high-speed connection. First, after picking up the receiver, dial o. This has the effect that the contact o opens and the election impulses can go out unhindered. As soon as the number 9 is raised, contact a is closed. The magnet Sp attracts i via its winding Sp I in the following circuit. Battery, relay A, Sp I, a, d, normally closed contact z, relay B, earth.

Via the contact i sp of the magnet Sp, the microphone in the pay phone switched off. Any adjustment on the dial remains completely ineffective, since the auxiliary contacts on the dial are bridged by the contact i sp. The magnet Sp therefore remains excited until the receiver is hung up. After this When the receiver is suspended, the magnet Sp is held by the contact 2 sp and its winding Sp II in series with relay A in the group selector until the connection in Office is triggered. The resistance of the winding Sp II is dimensioned so that the Relay A cannot hold. Trying to establish a connection by opening the Triggering the impulse contact has the effect that over the contact t likewise the magnet Sp is excited. Would the speaking guest try to pay a fee Establishing a connection without inserting a coin beforehand would also result in the blocking magnet Tighten Sp. Assuming the guest dials the number 3 q., then the magnet Sp would attract in the following circuits: z. Battery, A, Sp I, coin feeler lever contact mf, auxiliary contact O on the dial, normally closed contact from Z, relay B, earth.

If, on the other hand, the speaking guest establishes a connection to be dialed free of charge, e.g. B. calls the fire brigade whose number is oi, the magnet Sp would not respond when dialing this number, since the contact o should open as soon as an o is drawn. The under z. The described circuit would be interrupted at contact o. The chargeable connections, however, are characterized in that. there is no o in the first position, ie when the first digit is dialed, contact o is closed. If the speaking guest were to try to adjust the dialer by moving the handset hook quickly up and down in order to avoid switching the auxiliary contacts on the dial, this attempt would also not lead to any result, since the blocking magnet Sp in the following circuit picks up via contact 3 HU: 3 Soil, 3 HU, 3 sp; Sp I, A, battery. By opening the contact 3 Sp, the high-resistance winding Sp II is connected in series with the relay A , so that the relay A drops out and causes the group selector GW to collapse.

Claims (1)

PATENT CLAIM: 1. Circuit arrangement for self-connecting telephones in which auxiliary contacts controlled by the dial are used for blocking and grading different connections, which characterize the selected connection, in particular for coin-operated telephones, characterized in that the auxiliary contacts (a, d, o) have a attracting the magnet (Sp) blocking the connection, which can only be brought to waste by hanging the receiver to reset the auxiliary contacts. z. Circuit arrangement according to Claim I, characterized in that the blocking magnet (Sp) is placed in a holding circuit and remains excited until the connection is destroyed. 3. Circuit arrangement according to claim 1, characterized in that the connection blocking magnet (Sp) simultaneously determines the flow of the coin into the return container.