摘要:

A welder control is described which can deliver currents as high as 200 amperes R.M.S. for any predetermined time from a fraction of a half‐cycle of the 60‐cycle power supply to 60 half‐cycles. At any specified timing, the intensity may be controlled continuously from zero to its maximum value. The operation of the control depends on the co‐ordinated application of two electronic circuits which individually or together have many other uses. The one circuit is a regenerative d.c. amplifier which serves as a controlled square wave generator and the other is a ``biased multivibrator.'' The operation of these circuits is described in considerable detail so that they may be adapted to the solution of other electronic control problems. The construction of pool‐type mercury rectifiers and the life tests on these are also presented.

ISSN:0034-6748    

DOI:10.1063/1.1770151

出版商:AIP    

年代:1943

数据来源: AIP

摘要:

The technique of the radio transmission of cosmic‐ray information from the stratosphere has been improved as a result of field experience. The instrument described herein is believed to be a definite improvement over the previous instrument. The scaling down of the cosmic‐ray counts is now done at the ground station instead of at the transmitter. This necessitated a new means of modulating the transmitter, a new receiver, and a new recorder.

ISSN:0034-6748    

DOI:10.1063/1.1770152

出版商:AIP    

年代:1943

数据来源: AIP

摘要:

Measurement of the rate of flow of air during inspiration is important in respiratory physiology and for the design of protective respiratory devices. Methods that have been used previously are described and their limitations explained. A new instrument was constructed for such measurements, which offers no appreciable resistance to air flow. This instrument consists of a microscopic platinum wire suspended across the diameter of a 31.6‐mm tube. One end of the wire is attached to a fixed point and the other end to a fine spring. The displacement of the wire when air flows through the instrument is recorded photographically by a moving paper camera. The deflection of the wire is linear with air flow, and its inertia, lag, and frequency of vibration do not interfere with respiratory measurements. A low resistance valve and mask system complete the apparatus.

ISSN:0034-6748    

DOI:10.1063/1.1770153

出版商:AIP    

年代:1943

数据来源: AIP

摘要:

A light‐valve is described for providing single flashes of 3‐msec. duration of longer, operated and controlled electronically. It involves disclosure and closure of an aperture by two vanes, whose cycle is commutated automatically. Details are given for a model made mainly from commercial parts, and driven by thyratrons. A suitable control circuit is also shown.

ISSN:0034-6748    

DOI:10.1063/1.1770154

出版商:AIP    

年代:1943

数据来源: AIP

摘要:

A circuit is described comprising anRCoscillator and multivibrator which generate three timing scales suited to calibrate a wide range of sweep speeds. In addition, a square pulse with adjustable duration is provided to calibrate the gain and to record the frequency characteristics of an amplifier. Both calibrations are synchronized with the sweep.

ISSN:0034-6748    

DOI:10.1063/1.1770155

出版商:AIP    

年代:1943

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1770156

出版商:AIP    

年代:1943

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1770158

出版商:AIP    

年代:1943

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1770159

出版商:AIP    

年代:1943

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1770160

出版商:AIP    

年代:1943

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1770161

出版商:AIP    

年代:1943

数据来源: AIP