I.R.E. Special Committee on Obtaining MembershipTalents and Volunteer Service*E. FINLEY CARTERt, FELLOW, I.R.E. (Chairman)

] sURING the past year, a special committee wasappointed by the Executive Committee of theInstitute for the purpose of obtaining member-

ship talents and volunteer service to aid in broadeningparticipation in various Institute activities. The immedi-ate aim of this committee was to set up means of ob-taining lists of qualified individuals from which memberscould be selected for appointment to committees or toother assignments.

In exploring the possible approaches for accomplish-ing this aim, a number of conclusions were reached andrecommendations have been made to the ExecutiveCommittee and the Board of Directors. Some of theserecommendations were of a general nature while otherswere more specific in their relation to the procedures forselecting committee members and administering com-mittee activities.Among the specific recommendations was the one to

establish in each Section a Section Personnel Committeewhose function it would be to advise the National Officeof personnel whom it deemed capable of and interestedin serving on various committees of the Institute. Thislocal committee would also recommend members fortransfer from Associate to higher grades and assist suchmembers in making transfers by arranging for sponsorsand by securing and transmitting relevant informationto the Admissions Committee.The underlying reasons for the recommendation that

each Section have a Committee on Personnel can bemore fully appreciated in the light of the expansion thathas taken place both in membership and in the scope ofthe Institute's activities. It is no longer possible for theBoard of Directors or any similar group to be well versedin the qualifications and the personal interests of theInstitute's thousands of members. On the other hand,Personnel Committees in each of the various sectionscan know and appraise the talents of their respectivemembers and should, therefore, be able to render in-valuable service to the Institute through the recom-mendations they make. This service should result, notonly in more effective committees, but also in a betterdistribution and wider representation in Institute af-fairs. The work of the various Section Personnel Com-mittees may prove to be an important step in the de-centralization of that part of the Institute's administra-tive activities which can best be executed within theSections.

Although only two specific functions were enumeratedin Professor Turner's letter recommending that Section

* Decimal classification: R060. Original manuscript received bythe Institute, March 12, 1945.

Personnel Committees be set up in the various Sections,others will, no doubt, become apparent to these com-mittees as they get underway. In selecting the Com-mittee members, the Chairmen will probably want topick men who, through their associations, can well repre-sent the personnel of the entire Section.

Organization and Duties of Section Personnel CommitteesThe Chairman of the Section Personnel Committee

should be a man whose interest and abilities particularlyqualify him for the appointment. He should be assistedby committee members who are in the aggregate wellacquainted with most, if not all, of the Section's mem-bers and engineers of standing in near-by non-Sectionterritory. They should be familiar with the major ac-tivities of the Institute, the requirements for admissionto the various membership grades, and the interest andabilities of the Section personnel.As the name implies, the Section Personnel Commit-

tee should be a service group assisting the personnelcomposing the Section to derive the maximum benefitsfrom I.R.E. membership by making their individualcontributions through active participation in Instituteaffairs. By rendering this service effectively, the SectionPersonnel Committee can materially aid in assuringthe selection of interested and well-qualified personnelto man the many important Institute committees.

In order to carry out its work, the Section PersonnelCommittee should first obtain a list of all members with-in the geographical bounds of its respective Section.However, the list should not be limited to the partici-pants from their particular Section. It should also con-tain suggested names of any communication and elec-tronic engineers in the neighboring territory, eventhough not covered by a Section, which the Section Per-sonnel Committee believes should be included. This listshould be classified as to membership grades and shouldcontain pertinent information which will be helpful indetermining when members qualify for transfer tohigher grades. It should record interest and qualifica-tions of individual members to aid the Section PersonnelCommittee in supplying the National Office with in-formation which will allow the maintenance of a currentlist of personnel whose particular interest and abilitiesqualify them for work on committees or in other Insti-tute activities.From the data assembled for its working records, the

Section Personnel Committee can help the AdmissionsCommittee by first determining which members arequalified for transfer to a higher grade and then by con-tacting these members and helping those who want to

Proceedings of the I.R.E.1945 639

transfer to make certain that their applications containlsufficient information to aid the Admissions Committeein passing on these applications. By helping members incontacting the necessary sponsors and by seeing thatsponsors are provided with information to evaluateproperly the engineering accomplishments of the ap-plicants, the Section Personnel Committee can appreci-

ably aid the Admissions Committee in expediting thetransfers.

In the carrying out of its functions, the Section Per-sonnel Committee should seek to maintain the closestco-operation with Membership Committees in their re-spective Sections as well as with any other committeewhose activities involve personnel functions.

Vacuum-Tube Radio-Frequency-GieneratorCharacteristics and Application to

Induction-Heating Problems*T. P. KINNt, SENIOR MEMBER, I.R.E.

Summary-Induction heating at radio frequencies is rapidly takingits place in many industrial processes. The high-power vacuum tube,in the past used principally in radio applications, is now generatingradio-frequency energy for industrial use. To apply this energy prop-erly to industrial heating problems, it becomes necessary that engi-neers active in all phases of industry understand the characteristicsand limitations of the vacuum-tube radio-frequency generator.

The fundamentals of the vacuum-tube self-excited oscillator anddesign considerations which determine the characteristics of theradio-frequency generator are reviewed and illustrated. In general,the characteristics show a high-impedance, constant-current, varia-ble-voltage generator which requires manipulation of load circuitsto load the generator properly. Methods are illustrated for accom-plishing proper loading, and numerical examples are given illustrat-ing the formulas and procedures necessary to any induction-heatingproblems.

D) UE TO wartime conditions, radio-frequencyheating has had a chance to demonstrate thatit can be a very useful tool. The vacuum

tube used as a generator of this radio frequency hastherefore placed itself in industry along with the morecommon generators of electric energy. The vacuum-tube radio-frequency generator, like any other piece ofelectrical equipment, has its characteristics, and thesecharacteristics dictate its uses and limitations. It is thepurpose of this paper to define some of these character-istics and show how to apply the radio-frequency gener-ator properly to induction-heating problems.The phenomena of producing heat by an alternating

magnetic field was known as far back as the 1880s. In1890, Colby was granted a patent for heating in thismanner. In 1900, it is believed the first practical induc-tion furnace was placed in operation by Kjellin. It hastaken the ensuing years to produce electrical equipmentsuitable for supplying the alternating current at variousfrequencies for the purpose of induction heating. How-

* Decimal classification: R355.9X621.375.1. Original manuscriptreceived by the Institute, September 21, 1944; revised manuscriptreceived, June 8, 1945. Based in palt on a paper presented before thePacific Coast Technical Meeting of the American Institute of Elec-trical Engineers, Los Angeles, California, August 29-September 1,1944. Printed by permission of the A.I.E.E.

t Westinghouse Electric Corporation, Baltimore, Md.

ever, it has taken the need for "all-out" war productionduring these past years to provide the incentive forwide-spread use of this type of heating in industry.With this rapid advance in the use of induction heating,the use of the vacuum-tube oscillator as a source ofalternating power for induction heating has shown avery rapid advance.

Except in isolated cases, the small amount of induc-tion heating used in industry, prior to the present war,used power obtained from rotating machines or spark-gap oscillators. The vacuum-tube radio-frequency gen-erator, along with the vacuum tube itself, is now show-ing its usefulness in industry. Because the vacuum-tuberadio-frequency generator has been confined to the radiofield up to this time, its operation and its characteristicsare not too well known to those not connected with theradio industry.

Induction heating is now being done at frequenciesfrom 60 to 10,000 cycles and higher by rotating machin-ery. The rotating machine is a common source of power,and therefore its use and limitations for induction heat-ing are well known. Service and maintenance problemsare well established.The spark-gap oscillator finds its most useful range of

frequencies between 20 and 200 kilocycles. This type ofgenerator is very useful for certain specific applications.The main advantages are its simplicity and ease of oper-ating technique, while its limitations are power outputand reliability. New developments surrounding thespark gap itself, which are appearing now and will ap-pear after the war, will help better the output and relia-bility of this type of generator.The scope of both the rotating machine and the spark-

gap generator is limited, and it is for this reason thatthe vacuum-tube radio-frequency generator has steppedinto the picture to pick up where these other machinesleave off. The vacuum-tube oscillator can do many ofthe jobs now being done by the rotating machine or thespark gap, and in addition, do many more jobs whichneither of these types can accomplish. At the present

6Proceedings of the I.R.E.640 October, 1945