ISSN:0034-6748    

DOI:10.1063/1.1749162

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749163

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749164

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749165

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749166

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

A modification of Soller's balanced circuit for use of a single FP‐54 tube has been found which gives improved stability of balance and the possibility of use with galvanometers of high resistance. The theory of the circuit and detailed directions for calculating, setting up, and balancing it are given.

ISSN:0034-6748    

DOI:10.1063/1.1749167

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

A general method of determining the equivalent circuit elements of a network containing any number and arrangement of resistances with one variable impedance element involves plotting a graph of the reactive component of the impedance against the resistive component at different frequencies. Capacitance bridge measurements at audio‐frequencies with a Weston Photronic cell at different illuminations yield data for such a graph. Circles are obtained from which it is concluded that the impedance element itself is capacitative and maintains a constant phase difference of the order of magnitude of 10° between current and voltage. The impedance of the cell as a whole decreases radically with frequency. From the circles it is found that the equivalent resistance in series with the impedance element is of the order of 35 ohms and is independent of illumination and other variable factors. The equivalent resistance in parallel with the impedance element is of the order of several thousand ohms, decreases with illumination and varies from day to day. After illumination, more than ten minutes elapse before steady conditions are again attained in the dark. The impedance element itself is regarded as capacitance of the order of 0.5&mgr;f and a series resistance, each decreasing with frequency. The capacitance varies approximately inversely as the frequency raised to the 0.1 power, and the resistance inversely as the frequency raised to the 0.9 power. Fricke's equation relating the former exponent to the phase difference is found applicable. The capacitance increases and the resistance decreases with illumination. A general similarity to electrolytic polarization capacitance is noted. When an inductance coil is placed across the cell and the cell is illuminated with light of sinusoidally‐varying intensity, resonance is obtained at a definite critical frequency.

ISSN:0034-6748    

DOI:10.1063/1.1749168

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

The problem of securing records economically over a relatively long period of time, at moderate or high film speeds, led to the design of a new type of oscillograph. Two such instruments, one applied to the study of the Barkhausen effect and the other to the recording of processes in the internal combustion engine, are described. By using a short distance from the mirror to the film it is possible to secure oscillograph records with standard motion picture film. It is shown that the record suffers no inaccuracy by this change from the conventional type of oscillograph. At the routine film speed of 25 feet per second, as used in the engine oscillograph, the shape of the record is similar to a standard oscillograph record at a speed of 160 feet per second. The fineness of the trace can be extended almost to the limit set by the resolving power of the film itself. The errors due to the increased values of the tangent of the angle of deflection are within one percent. Provision is made for viewing the light track, although the scale is too small to make the instrument especially valuable for viewing purposes. A time scale is established on the records without use of a vibrator element.

ISSN:0034-6748    

DOI:10.1063/1.1749169

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749170

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749171

出版商:AIP    

年代:1933

数据来源: AIP