Browse Prior Art Database

Auto Power Tap with Neat Threshold

IP.com Disclosure Number: IPCOM000113006D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Oka, Y: AUTHOR [+2]

Abstract

Disclosed is a circuit for automatic power tap using solid-state relay. This circuit avoids one directionally conductive state of solid-state relay, which is common phenomena when input level is around the threshold level of solid-state relay. This circuit can also provide appropriate hysteresis characteristics against master current and constant slave-on-delay without separate power supply. Low power dissipation circuit which is operative at low supply voltage brings these advantages.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 73% of the total text.

Auto Power Tap with Neat Threshold

      Disclosed is a circuit for automatic power tap using
solid-state relay.  This circuit avoids one directionally conductive
state of solid-state relay, which is common phenomena when input
level is around the threshold level of solid-state relay.  This
circuit can also provide appropriate hysteresis characteristics
against master current and constant slave-on-delay without separate
power supply.  Low power dissipation circuit which is operative at
low supply voltage brings these advantages.

      The Figure shows an example of this circuit.  Plug (1) is
connected to wall outlet.  Master equipment is connected to master
receptacle (2), slave equipments to slave receptacles (9)
respectively.  Current transformer (3) transforms the level of master
current to corresponding voltage level.  When master current exceeds
the threshold, slave equipments turn on automatically.  Three serial
diodes (4) regulates the supply voltage of CMOS IC HC132 (5) and
stabilizes the threshold level and the hysteresis characteristics of
HC132.  CR (6) provides required slave-on-delay.  While solid-state
relay (7) is off, LED (8) sinks current whose amount is equal to
input current of solid-state relay to avoid sudden voltage drop when
solid-state relay switched on because output impedance of the current
transformer is relatively high.

      One directionally conductive state of solid-state relay is
avoided by setting the threshold agains...