US1839451A - Power source - Google Patents

Description

32- P. Tmz 1,839,451

POWER SOURCE Filed Dec. 29, 1937 INVENTOR PAUL TAETZ TORNEY Patented Jan. 5,1932

UNITED STATES PAUL TATZ, 0F BERLIN, GERMANY, ASSIGNOR TQ GES ELLSCHAFT FUR DRAHTLOSE TELEGRAPHIE M. B. 11., OF BERLIN, GERMANY, A CORPORATION OF GERMANY POWER SOURCE Application filed December 29, 1927, Serial No. 243,259, and in Germany February 18, 1927.

The necessity of providing calling devices becomes more and more felt in proportion as radio frequency intelligence transmission means and methods become more popular. Among the various methods adapted to effecta radio frequency call the one appears most reliable in practice in which the calling transmitters when sending out a call are modulated with a suitable alternating frequency seeing that in this case the altternating frequency amplifier means provided at most receiver apparatus can be used for extending the calling range for the call.

An object of the present invention is to disclose ways and means in connection with this calling method adapted to realize considerable savings in the production of the calling frequency.

Other objects of the invention will be evident from the following description in connection with the drawings in which Fig. 1 represents a preferred embodiment of my invention in which the calling frequency is taken off in shunt relation, and

Fig. 2 shows another embodiment in which the calling frequency is taken off in series relation.

According to the idea underlying this invention, the call (modulation) frequency is derived directly from the direct current service machines providing currentfor the filament and the plate, the calling frequency consisting of the commutation frequency (commutator ripples) of these direct current machines. The call frequency may be taken from the machines, as shown in Fig. 1, either in shunt relation to the terminals of generator G, or else, as illustrated in Fig. 2, in series relation with the main service current. T are required which are markedly biased by the preponderant direct current component of the service current, and this is attended with difliculties. Another inconven- In this latter scheme, transformers ience is that in this circuit arrangement, the transformer must be adapted to the large service currents. V

For this reason, it is recommendable to derive the call frequency in shunt across the generator terminals, if possible, by way of a condenser C, Fig. 1 from the working potential.

In order to purify the call frequency, filter circuits S may be used in addition.

The call frequency, generally speaking, needs to be of only limited energy since the transmitters are mostly furnished with input amplifiers and modulating means, for which reason energy being only of an order of magnitude equalling the normal control energy (microphone energy) is required. Otherwise the modulation frequency may be conveniently amplified.

H avingthus described my invention what I desire to protect by Letters Patent is as follows:

1. In an arrangement for audio frequency modulation of radio frequency transmitters, a source of direct current for energizing said transmitters said source having alternating current components, and means for utilizing the alternating current components on said direct current for modulating said transmitters.

2. A method of deriving modulating energy from existing transmitting station equipments which comprises filtering out and utilizing the commutator ripples in the existing direct current supply generators.

3. In a system for modulating radio frequency transmitter circuits with audio frequency energy, means for deriving said audio frequency energy comprising a circuit coupled to the direct current generators of the transmitter power supply system said circuit being adapted to transfer from said generators to said modulating system any alternating current energy component present in said generator circuit.

circuit.

PAUL TATZ.

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