Switchover system for binary load control
First Claim
1. A system for controlling the energization of a load-operating impedance element connected across a power supply, comprising:
- a high-resistance d-c circuit branch in series with said impedance element, said branch including a voltage limiter, a voltage multiplier with an input energized by said voltage limiter and a switching stage energized by said voltage multiplier, said switching stage having an output carrying a potential whose absolute magnitude is higher than that of the maximum output voltage of said voltage limiter in a first operational state and is lower than that of said maximum output voltage in a second operational state thereof;
a differential amplifier having a first input connected to said voltage limiter in parallel with the input of said voltage multiplier and having a second input connected to the output of said switching stage for emitting a binary switchover signal depending on the operational state of said switching stage;
command means connected to said switching stage for altering the operational state thereof in response to a control variable;
andvariable-resistance means coupled to said differential amplifier and responsive to said switchover signal connected across said branch in series with said impedance element for providing a low-resistance current path in one operational state and a high-resistance current path in the other operational state of said switching stage, thereby causing said impedance element to be traversed by a relatively large load current in said one operational state and by a relatively small load current in said other operational state, the voltage drop across said low-resistance current path being sufficient to maintain the energization of said switching stage in said one operational state.
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Accused Products
Abstract
A system for alternately activating and deactivating a load comprises a high-resistance d-c circuit branch connected across a power supply downstream of a load-operating impedance, this branch including a voltage limiter and a voltage multiplier in series with each other and with a switching stage responsive to commands from a timer and/or a parameter sensor such as a thermostat. The junction of the voltage limiter and the voltage multiplier is connected to one input of a differential amplifier whose other input is energized with either of two potentials, respectively higher and lower than that of the junction, by the switching stage. The amplifier output controls a variable-resistance element, such as a transistor of the bipolar or the MOSFET type, connected across the high-resistance branch to form a current path in series with the load-operating impedance, the resistance of this path being variable between a high value minimizing the flow of load current and a low value sufficient to maintain the switching stage operational. A standby source may be provided for keeping the switching stage or at least an electric timer thereof energized during interruptions of the main power supply.
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Citations
10 Claims
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1. A system for controlling the energization of a load-operating impedance element connected across a power supply, comprising:
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a high-resistance d-c circuit branch in series with said impedance element, said branch including a voltage limiter, a voltage multiplier with an input energized by said voltage limiter and a switching stage energized by said voltage multiplier, said switching stage having an output carrying a potential whose absolute magnitude is higher than that of the maximum output voltage of said voltage limiter in a first operational state and is lower than that of said maximum output voltage in a second operational state thereof; a differential amplifier having a first input connected to said voltage limiter in parallel with the input of said voltage multiplier and having a second input connected to the output of said switching stage for emitting a binary switchover signal depending on the operational state of said switching stage; command means connected to said switching stage for altering the operational state thereof in response to a control variable; and variable-resistance means coupled to said differential amplifier and responsive to said switchover signal connected across said branch in series with said impedance element for providing a low-resistance current path in one operational state and a high-resistance current path in the other operational state of said switching stage, thereby causing said impedance element to be traversed by a relatively large load current in said one operational state and by a relatively small load current in said other operational state, the voltage drop across said low-resistance current path being sufficient to maintain the energization of said switching stage in said one operational state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification