DE1060916B - Switching device for portable telephones with OB operation - Google Patents

Description

GERMAN

The invention relates to a switching device for portable telephone sets with OB operation according to patent application K 25443 Villa / 21a ² .

Subject of the main patent application is a portable telephone set with a local battery, in which for a particularly weight-saving training in connection with a battery-free microphone Standing transistor amplifier for generating a ringing signal can be switched into a tone frequency generator is. In the ringing circuit, the transistor amplifier then acts as a tone frequency generator the calling station a tone-frequency ringing voltage of around 1000 to 2000 Hz for the call, which is reproduced in the called station through the earpiece of the listener.

The present invention aims to provide a switch for systems with several Intercom stations of the type described above. Here, the task arises, suitable, on the audio-frequent Provide call-responding call organs for the switch cabinet.

Furthermore, a device must be provided at the exchange, which in a simple manner the transmission of a tone-frequency call voltage to the place to be called is permitted.

According to the invention, these objects are achieved in that in the switching cabinet for reception of the tone-frequency ringing signals sent from a subscriber station a responsive to direct current Call organ (drop flap) in series with a single one acting as an amplifier and rectifier Transistor stage is switched.

It is already known per se for other purposes, a display element which responds to direct current a two-stage transistor circuit acting as a rectifier and amplifier must be arranged in front. The well-known However, the device does not serve to solve the problem underlying the invention, according to which a switching cabinet that was previously only used for direct current signals or for low-frequency signals to be made usable for audio-frequency signals without affecting the operation and the device, for example made more difficult and difficult by the need to use additional power sources gets complicated.

It is also known per se, in a circuit arrangement for advancing the charge displays assigned to the subscribers of an exchange-powered telephone network, the preferably non-tone-frequency alternating current pulses transmitted during the call via the speech wires via a transformer to a single transistor stage which acts as an amplifier and rectifier and ( responding to direct current or to direct current pulses-switching device for portable
Telephone sets with OB operation

Addition to patent application K 25443 VIHa / 21 a ²

Applicant:

Heinz Kunckel,

Berlin-Dahlem, Helfferichstr. 78

Heinz Kunckel, Berlin-Dahlem,
has been named as the inventor

actuates the) charge counter. In the known arrangement, the transistor stage is derived from the central battery fed by the office; for a switching device in connection with portable telephone sets The known arrangement cannot therefore be used without further ado in OB operation.

According to an advantageous embodiment of the invention it is provided that the transistor stages of Call organs (drop flaps) and a transistor provided in the interrogation device from a common Battery powered.

According to a further particularly advantageous embodiment of the invention it is provided that the Interrogation device with its call and speech circuits switched in the same way as a subscriber station is.

Further advantages and details of the invention emerge from the following description of a Embodiment based on the drawing. In this shows

Fig. 1 an OB telephone station according to the main patent application K 25443 VIIIa / 21a ² with the insignificant difference that the call button RT is two-pole and arranged at another point in the circuit,

Fig. 2 the circuit of a unit of a switching device for a working with tone-frequency call Telephone system, in connection with the interrogation device provided on the switch cabinet.

909 560/102

10

In the drawing, the characters mean:

La, Lb line connections for one point,

AD Lockable query button in the exchange,

RT call button in the telephone station,

RT ₁ call button in the exchange,

ET push-to-talk button in the handset,

VK attendant,

VSt switching plug,

Tr transistor in the telephone station

(Fig. 1),

Tr ₁ transistor in the switching device (Fig. 2) with base connection B, emitter connection E and collector connection K,

AK call flap,

C capacitor,

B ₁₃ B ₂ batteries,

VS switching facility,

Mi microphone,

Te remote receiver,

R ₁ resistor 1,

R ₂ resistor 2,

Λ ^Γ replication resistance,

Ü Transformer with the windings W ₁ , W ₂ ,

W 'W ² ^

^v ' 2 ' 3 '

Afr interrogator with the connection points La, Lb, I, II, III, IV, V for
Completion according to Fig. 1.

The switching device shown works as follows: In the idle state, the input B, E of the transistor Tr ₁ in the switching center is connected to the line La, Lb of the associated intercom via the break contacts of the query button AD and the switching jack VK. The call flap AK is in the collector circuit of the transistor, in which only the very small residual collector current now flows, so that the flap does not fall. If a tone-frequency voltage occurs at the terminals La, Lb when a call is sent from the intercom in Fig. 1, the half-waves, at which the base becomes negative in relation to the emitter, cause increased current surges in the collector circuit. This creates a pulsating amplifier direct current, which is smoothed by the capacitor C lying parallel to the winding of the call flap AK. This makes it possible to receive sufficient direct current in the winding of AK in the event of incoming ringing voltages of a few tenths of a volt in order to operate the drop flap.

To connect two speech stations, the switching plug VSt assigned to the first speech station is inserted into the switching jack VK allocated to the second speech station; the input of the transistor Tr ₁ assigned to the second call station for the call flap AK (or the flagship relay) is disconnected. However, the transistor of the first call station remains connected to the line La, Lb , so that there is a possibility of receiving the final call signal, which is caused by the call signal of one of the two subscribers.

By pressing the query button AD , the operator can switch on the existing connection between the two subscribers. When the query button AD is pressed, the La line is disconnected from the base of the associated transistor. If the switch is switched on by pressing the query button assigned to the first intercom, the assigned transistor Tr ₁ , which was still on the line, is also disconnected from the line, so that now both transistors are switched off. If the switching on of the switching takes place alternatively by actuation of the query button assigned to the second intercom station, the transistor Tr ₁ assigned to the first intercom station remains connected to the speech line.

The query buttons of the various connection units are designed in a known manner so that the previously pressed and then locked key is triggered when another key is pressed will.

For the transmission of a tone-frequency call, the interrogation device Afr is provided in the exchange, the call and speech circuits of which are connected in the same way as with a subscriber station. In Fig. 2 only a few circuit elements of this stage are shown to identify the connection points I to V. The complete circuit is to be supplemented analogously to Fig. 1, but the operating voltage is switched on by pressing a query button AD . The call button RT ₁ is conveniently located in the control panel of the switch cabinet.

Instead of the call fold, other call organs can of course also be used, such as indicators, are provided.

Claims (4)

Patent claims: 1. Switching device for portable telephones with OB operation according to patent application K 25443 VIII a / 21 a ² , characterized in that to receive the audio-frequency call signals sent out by a subscriber station a direct current responsive call organ (case flap) in series with a single as an amplifier and Rectifier acting transistor stage is connected. 2. Switching device according to claim 1, characterized in that the input circuit of the transistor stage is separated on the base or emitter side when operating an associated interrogation device (button AD, switching plug VSt) . 3. Switching device according to claim 2, characterized in that the transistor stages of the call organs (drop flaps) and a transistor provided in the interrogation device a common battery. 4. Switching device according to claim 3, characterized in that the interrogation device is switched with their call and speech circuits in the same way as a subscriber station. Considered publications:
German Patent No. 899,373;
Funk-Technik, 1954, issue 22, pp. 621/622. 1 sheet of drawings © 909 560/102 6.59