DE826167C - Circuit arrangement for telephone bill displays and coin telephones - Google Patents

Description

Circuit arrangement for telephone charge displays and payphones In the known circuits for telephone charge displays, the counting pulses during or after the conversation with alternating current over the subscriber line transfer. In the office, a special relay transmission is necessary, which after The end of the call switches to alternating current metering or to the initially smoothly connected Speaking branches create a simultaneous circuit at the beginning of the conversation. The simultaneous transmission is asymmetrical, gives rise to crosstalk and affects low crosstalk values the count in the neighboring circuit.

The charge indicator set up for AC control at the Participant is a fairly extensive apparatus.

The invention relates to a switching device, %% - oak the extensive relay transmission that interferes with the wiring of the office avoids the additional switching elements required in the office in the smallest form, may also be accommodated within the participant counter and a symmetrical transmission of the counting current impulses over the speech wires is allowed. To achieve the least possible effort, the fee indicator is at Participants made very small, so that they can also be conveniently placed in the housing of an inquiry device can be accommodated.

The counting current surges are in the office during the conversation or after termination of the conversation by means of a long-wave high-frequency current, the frequency of which is outside of the audible range is transmitted symmetrically via the branches of the line. Well proven have about 15 kI-iz. Fig.i shows the basic electrical and mechanical switching device.

Two normally open contacts z activated by the subscriber counter attach a high-frequency generator (e.g. 15 kHz) to the a and 6 lines each time the counter Z is activated via small coupling capacitors that are housed in the counter housing or in the wiring. In order to avoid a change in energy, the line to the office can be blocked off by high-frequency chokes (shown in dashed lines) or blocking circuits. The transmitter is expediently dimensioned so that its internal resistance is predominantly inductive in order to compensate for the capacitive load on the cable line.

The use of high frequency has the advantage that the coupling members can be made very small and therefore cheap and take up little space. It also succeeds in reducing the insertion loss in the voice frequency range and the To keep interfering noises from capacitor charging surges and switch-on processes to a minimum. A switch-on and switch-off noise that may still be perceived as annoying can be almost completely eliminated by flattening means on the generator, e.g. B. by a high-pass filter that suppresses the audible frequencies of the switch-on surge, or by a large time constant, which slowly settles the load current leaves. Good results can also be achieved with a high-frequency choke that turned on across the coupling capacitors on the side facing away from the speaking branches will.

In the subscriber set, the high-frequency stream is transmitted via one of the speech streams blocking resonance circuit branched off, rectified and a sensitive relay fed. Here, too, the call station circuit can be shunted if necessary be sealed off by high-frequency chokes or blocking circuits in order to e.g. B. a fee evasion for coin operated telephones by lifting the dial (short-circuiting of the speakers) to avoid.

The movable part of the receiving relay is designed so that it either directly with the help of a pawl or an anchor (like a Clock armature) a wheel shifts step by step or that he indirectly after the Servo principle releases a clockwork for one step, in which he, for example, like The balance wheel of a clock can be switched one step further via an anchor. The clockwork is activated using the delete key or the hook switch or the Dial raised.

The display device required by the participant is expedient in the front part of the extended telephony device housing, z. B. a consultation machine, built-in (Fig. 2). It is housed in this way in a pleasing form and very easy to read. A clear key sets the pointers or the number discs or back the number drums in a known manner with the help of a heart curve. the It can also be reset automatically when the llörer @ cltircli den is unhooked Hook switch or done by the elevator of the dial.

The counting method is meaningful for payphones with counting applicable during the conversation. The receiving relay excited by the high frequency current is either designed as a cashier magnet and feeds vain coins in the cash register or it activates a third party with the use of the servo riiizip fed Kassierniagtiet.

Claims (7)

PATEN TA VCi'RÜCHG: i. Circuit arrangement for telephone charge displays and coin-operated telephones, characterized in that the counting current surges are transmitted symmetrically over the two speech wires by means of a long-wave high-frequency current (e.g. 15 kHz) lying outside the audible range. 2. Circuit arrangement for charge displays and coin operated telephones according to Allspruch t, characterized in that the high-frequency generator in the office has two contacts, which are operated by the call counter, and two coupling capacitors, which are im Housing of the call counter or housed in the wiring, switched on and that, if necessary, an approximately audible switch-on and switch-off surge by flattening means on the generator (e.g. through a high-pass filter) or on the coupling element (e.g. through a transverse choke in front of the capacitors) and to avoid energy leakage the line leading to the office is locked by high-frequency chokes or blocking circuits will. 3. Circuit arrangement for charge indicators and payphone according to claim i and 2, characterized in that the high frequency stream in the subscriber set or pay phone picked up via a resonance circuit blocking the speech currents, rectified and fed to a specially trained sensitive receiving relay is, if necessary with interlocking of the line leading to the speech circuit by high-frequency chokes or i51) circuits. 4. Circuit arrangement for fee displays according to claim i, 2 and 3, characterized in that the receiving relay at each Counting pulse with the help of a pawl or an anchor (similar to that of a clock) a wheel immediately advances one step. 5. Circuit arrangement for charge indicator according to claim i, 2 and 3, characterized in that the receiving relay releases a spring-operated clockwork according to your servo principle for one step with each counting pulse by, for example, like the balance wheel of a clock via an armature a climbing wheel one step can continue to rotate. Ergänzungsblatt; Ur Patentechr i ft 826,167. K1, 21a Gr. ä6 Oä The patent 82E 167 has been declared invalid by the German Patent Office on October 11, 1955 as follows: Claims 3, 4 and f are deleted. Claim 1 is replaced by the following: "Circuit arrangement for 5 rnaprsch charge displays, which are controlled by long-wave high-frequency currents symmetrically transmitted over the two speech lines by means of a long-wave high-frequency electricity stream, which is formed by means of a long-wave high-frequency electricity stream that is symmetrically transmitted over the two speech cores saving removed Spreenatröme, rectified and a sensitive receiver relay is fed, which at each count pulse with "a pushing pawl or armature Chnlieh üilfe the a clock) a wheel of the charges indicator immediately a step weiterachaltet."'in claim 2 in the preamble C, line the Word sequence '° and lünzfernsprecher "deleted.' In claim 5, line 2 ", 2 and 3" are replaced by "and V, in claim 6, Ze 1e 2" 3, 4 "is replaced by" 1 11 . 6. Circuit arrangement for fee displays according to claim 3, 4 and 5, characterized in that the at Subscriber required display device in the front part of the extended telephone housing (z. B. an inquiry device housing) is housed and the pointers, number discs or number drums by hand with a delete key or automatically when hanging out again of the handset by the hook switch or by the dial to the rest position be reset and at the same time wound up any existing clockwork will. 7. Circuit arrangement for pay phone according to claim i, a and 3, characterized characterized in that the receiving relay works directly as a cashier magnet or controls an externally fed cashier magnet.