GB2327819A

GB2327819A - Power controller for a computer peripheral

Info

Publication number: GB2327819A
Application number: GB9716096A
Authority: GB
Inventors: Tony Pollard
Original assignee: NEUTRAL Ltd
Current assignee: NEUTRAL Ltd
Priority date: 1997-07-31
Filing date: 1997-07-31
Publication date: 1999-02-03
Also published as: GB9716096D0

Abstract

A power control arrangement ensures that a computer peripheral is automatically turned on or off whenever the computer is turned on or off respectively. An AC power supply and control device has a socket 11 for the computer and sockets 12 for the peripherals. An AC power input lead 10 is coupled directly to the socket 11, and via a relay switch (21, Fig.2) to the sockets 12. The relay switch (21) is closed when the computer is on, the relay being operated by the 5 volt supply available at the keyboard port, or another port, on the computer. The 5 volt supply is coupled to the relay (21) via a cable 14 and connectors 13, 15.

Description

COMPUTER PERIPHERAL POWER CONTROLLER This invention relates to computer peripheral power control.

Computer systems often have peripherals attached which have separate connections to power outlets. Many computer peripherals have AC to DC adaptors which use power even when the peripheral itself is turned off. It is convenient and energy efficient to automatically turn on or off all the peripherals on a computer whenever the computer itself is turned on or off.

There are well known devices which can automatically turn on or off all the peripherals on a computer. These devices are based on either monitoring the current drawn from a master power outlet (which the computer is plugged into), or using a microcontroller to communicate with the computer. The slave power outlets are then powered accordingly. These are relatively expensive.

Moreover the master/slave technique may not work with computers that still draw a small current when turned off.

According to the present invention there is provided a computer peripheral power controller for a computer system having at least one peripheral with an AC power plug, an apparatus for powering the peripherals in synchronization with the computer, comprising an input port for receiving input power from the computer, a means for using said input power to activate said peripheral, a power receptacle or receptacles for receiving said AC power plug, a connection circuit responsive to said input power for coupling said AC power receptacle to an AC power source thereby providing AC power to said peripheral, and a connection circuit responsive to the absence of said input power for decoupling said AC power receptacle from an AC power source thereby disconnecting AC power from said peripheral.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows in perspective the apparatus; Figure 2 shows the circuit diagram.

Referring to the drawing the apparatus comprises AC power lead 10, computer power outlet 11, peripheral power outlets 12, input socket 13, computer port cable 14 and the circuit of figure 2.

Whenever a computer is on it supplies 5 volts power from it's keyboard port connectors. Using the two-way cable adaptor 15 this five volt line is taken out by cable 14 to the input socket 13 where it is used by the circuit in figure 2, (connection 25) to close the contacts of power relay 21. This relay then connects mains power to a number of power outlets 12 which the computer peripherals may be plugged into. Turning off the computer causes the relay 21 to open and turn off the peripherals.

The diode 22 is to protect the computer from back-EMF from the relay. The capacitor 23 ensures that electrical noise on the computer port cable 14 doesn't accidentally trigger the relay 21. The fuse 24 is a solid-state autoreset type that protects the computer from a fault on the relay 21. The extemal mains power is connected from the AC power lead 10 to point 26, and from point 27 to the peripheral power outlets 12.

The computer power outlet 11 is continuously powered since it is connected directly to AC power lead 10.

In order to provide additional protection to the computer the apparatus may include well-known surge suppression and/or filtering circuits. Also, instead of drawing power from the keyboard port the apparatus may draw power from another port on the computer using an appropriate connector for adaptor 15. There may be more than one un-controlled outlet (as in computer power outlet 11).

Claims

In a computer system having at least one peripheral having an AC power plug, a computer peripheral power controller for controlling AC power provision to said peripheral or peripherals, comprising, an input port for receiving input power from the computer, a circuit for using said input power to activate said peripheral, a power receptacle or receptacles for receiving said AC power plug, a connection circuit responsive to said input power for coupling said AC power receptacle to an AC power source, thereby providing AC power to said peripheral, a connection circuit responsive to the absence of said input power for decoupling said AC power receptacle from an AC power source, thereby disconnecting AC power from said peripheral.
2 A computer peripheral power controller as claimed in claim 1 wherein protection means are provided for protecting the computer from over voltage and faults.
3 A computer peripheral power controller as claimed in claim 1 or claim 2 wherein circuit means are included for avoiding inadvertent activation of said peripheral through electrical noise.
4 A computer peripheral power controller as claimed in claim 1, 2 or 3 wherein protection means are provided for suppressing surges or noise from the AC power source.
5 A computer peripheral power controller as claimed in claim 1, 2, 3 or 4 wherein means are provided for AC power receptacle or receptacles which are not subject to control.
6 A computer peripheral power controller substantially as described herein with reference to figures 1 and 2 of the accompanying drawing.