Shock-proof mains voltage supply outlet and method
First Claim
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1. A method of rendering an outlet having terminals connected to a mains power supply of predetermined supply voltage safe from shock upon human touching of the outlet terminals, that comprises, sensing whatever impedance may be presented between said terminals;
- responding to said sensing to apply only a fraction of said predetermined supply voltage from said supply for sensed impedance values corresponding to the relatively high impedance presented by the human body, wet or dry, or by animals; and
responding to said sensing to apply substantially full predetermined supply voltage for sensed impedance values corresponding to the relatively low impedance presented by appliances.
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Abstract
An improved mains outlet and method of operating the same that automatically and safely distinguishes between the conditions of human or animal contact with the outlet terminals and contact with appliances such as light bulbs and consumer products, to prevent any substantial voltage or power from being drawn in the former case and automatically applies substantially full mains voltage when the appliance is connected to the outlet.
26 Citations
10 Claims
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1. A method of rendering an outlet having terminals connected to a mains power supply of predetermined supply voltage safe from shock upon human touching of the outlet terminals, that comprises, sensing whatever impedance may be presented between said terminals;
- responding to said sensing to apply only a fraction of said predetermined supply voltage from said supply for sensed impedance values corresponding to the relatively high impedance presented by the human body, wet or dry, or by animals; and
responding to said sensing to apply substantially full predetermined supply voltage for sensed impedance values corresponding to the relatively low impedance presented by appliances. - View Dependent Claims (2, 3)
- responding to said sensing to apply only a fraction of said predetermined supply voltage from said supply for sensed impedance values corresponding to the relatively high impedance presented by the human body, wet or dry, or by animals; and
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4. A method of rendering an outlet having terminals connected to a mains power supply of predetermined supply voltage safe from inflicting shock upon human touching of the outlet terminals, that comprises, interposing an impedance-sensitive electronic circuit between the terminals and the power supply lines, said circuit having electronic switching means;
- biasing said electronic switching means to permit only a fraction of said predetermined supply voltage to be passed through the circuit from the power supply lines to the outlet terminals when impedances well above several hundred ohms are connected thereacross, as when human fingers, wet or dry, touch the terminals; and
adjusting said electronic switching means to become substantially fully conductive to apply substantially full predetermined supply voltage from the supply line to the said terminals when a load impedance less than several hundred ohms, as from electrical appliances, is connected across said terminals. - View Dependent Claims (5)
- biasing said electronic switching means to permit only a fraction of said predetermined supply voltage to be passed through the circuit from the power supply lines to the outlet terminals when impedances well above several hundred ohms are connected thereacross, as when human fingers, wet or dry, touch the terminals; and
- 6. An outlet having terminals for applying predetermined supply voltage from mains power supply lines to the outlet terminals having, in combination, an electronic circuit interposed between the supply lines and the outlet terminals and comprising electronic switching means to prevent any more than a fraction of said predetermined supply voltage from being applied to said outlet terminals when the impedance presented thereacross is of the relatively high impedance values presented by the human body, and means automatically operable upon the presenting between said outlet terminals of the relatively low impedance values of appliances for causing the switching means to apply thereto substantially full predetermined supply voltage from said supply lines.
Specification