• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A study of a low-intermodulation triode plate mixer

Holder, Floyd Pierson 08 1900 (has links)
No description available.
2

COMPUTER-AIDED DESIGN OF THERMIONIC INTEGRATED CIRCUIT ACTIVE DEVICES.

SCHOENEMAN, DONALD WARREN. January 1985 (has links)
Two computer-aided design methods are described in this dissertation for the design of Thermionic Integrated Circuits (TIC). Such circuits combine vacuum tube techniques with modern integrated circuit techniques to produce microminiature vacuum tube circuits, with possibly hundreds of vacuum triodes on a single substrate. The first method described in the line charge approximation technique in which the TIC devices are modelled as collections of line charges. A TIC is produced by evaporating metal electrodes on one or two sapphire substrates. The entire structure is heated to about 850°C so that electrons are emitted from the cathode electrodes to travel to the plate electrodes as in a conventional vacuum triode. The line charge approximation method is easy to implement and provides a simple means of satisfying the sapphire dielectric boundary conditions of the TIC basic problems, which are electrostatics problems since space charge effects are neglected. The method requires only a single matrix inversion and is a finite element Green's function approach. The method uses no iteration as in previous TIC analysis methods. Later as the development of TIC devices proceeded further it was found that conducting shields had to be placed over the unused sapphire surface so that the basic problem became a metal box problem. For this case a second method was developed called the step and ramp function method in which each electrode is modelled by a step function, which is the electric field solution for a potential step on a zero potential boundary. A superposition of these step functions models the TIC electrodes. The method provides direct calculation of the electric fields from equations and requires no iteration or matrix inversion. The potential variation between electrodes is modelled by linear potential functions called ramps. A superposition of steps and ramps completely specifies a TIC structure. The method does not solve for the case of electrodes which are elevated above substrates. For this case a modified line charge method was developed but not implemented.
3

Σχεδίαση και σύγκριση ενισχυτών ηχητικών συχνοτήτων διαφόρων τεχνολογιών

Πυροβολάκης, Γεώργιος 07 June 2013 (has links)
Η παρούσα διπλωματική αποτελείται από μια σειρά από projects συστημάτων επεξεργασίας ηχητικού σήματος, με κύριο προσανατολισμό το ηχητικό σήμα της ηλεκτρικής κιθάρας. Πολλά από τα ακόλουθα projects είναι βασισμένα σε ήδη υπάρχοντα κυκλώματα που κυκλοφορούν στο εμπόριο και έχουν τροποποιηθεί έτσι ώστε να έχουν βελτιωμένη απόδοση (λιγότερος θόρυβος, μικρότερη κατανάλωση ισχύος) και να έχουν καλύτερη ηχητική απόκριση (σύμφωνα με τα δικά μας -υποκειμενικά- κριτήρια). Τα πρώτα projects ως ενεργά στοιχεία χρησιμοποιούν είτε διακριτά τρανζίστορ και διόδους, είτε ολοκληρωμένα κυκλώματα τρανζίστορ-διόδων. Τα δύο τελευταία χρησιμοποιούν τριοδικές και πεντοδικές λυχνίες κενού. Με αυτόν τον τρόπο έχει επιτευχθεί και μια κλιμακούμενη αύξηση της δυσκολίας των projects. / --

Page generated in 0.029 seconds