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BI-DIRECTIONAL THYRISTORING GATING CIRCUIT

IP.com Disclosure Number: IPCOM000022981D
Original Publication Date: 1976-Jun-30
Included in the Prior Art Database: 2004-Mar-27
Document File: 2 page(s) / 193K

Publishing Venue

Xerox Disclosure Journal

Abstract

Previous methods of controlling AC loads through TRIACS used optically coupled devices to gate the TRIACS with low level logic signals. The optical couplers are unidirec~ tional and, therefore, gate voltage must always be of one polarity. This results in a gate voltage which must be out of phase with the TRIAC main terminal voltage for at least7T radians.

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Page 1 of 2

XEROX DISCLOSURE JOURNAL

BI-~flIRECTIONAL THYRISTORING
GATING CIRCUIT
William L. Valentine

Proposed Classification
U.S. Cl, 307/252

mt. Cl, H03k 17/60

AC HOT + GATE SIG. TO LOAD

Previous methods of controlling AC loads through TRIACS
used optically coupled devices to gate the TRIACS with low
level logic signals. The optical couplers are unidirec~
tional and, therefore, gate voltage must always be of one
polarity. This results in a gate voltage which must be
out of phase with the TRIAC main terminal voltage for at
least7T radians.

It is proposed to use an optically coupled device 1 to
enable a bi~directional analog switch 2. The use of a bi~
directional analog switch 2 in the gate circuit to the
TRIAC 3 permits the use of a gate signal which is always
in phase with the TRIAC main terminal voltage. This pro~
vides a means for gating a TRIAC with levels or pulses
which are always in phase with the main terminal voltage.
As a result the magnitude of the gate current required
is reduced. This in turn enables use of a low power
gating supply 4.

4

Volume 1 Number 6 June 1976 71

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72 XEROX DISCLOSURE JOURI'&L

Volume 1 Number 6 June 1976

[This page contains 1 picture or other non-text object]