SAFETY CHAIN CIRCUIT
First Claim
1. A safety chain circuit for use with a control system that provides a first control signal and a second control signal, the safety chain circuit comprising:
- a plurality of protection devices serially connected between a first chain end and a second chain end; and
an amplifier including a first device switch and a second device switch serially connected between a power input and a power output, a first enabling switch connected between the second chain end and a second enabling switch, and a first control switch and a second control switch;
wherein the first enabling switch is operable to enable the first control switch to control the first device switch, and the second enabling switch is operable to enable the second control switch to control the second device switch; and
wherein the enabled first control switch is operable to control the first device switch in response to receiving the first control signal, and the enabled second control switch is operable to control the second device switch in response to receiving the second control signal.
1 Assignment
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Accused Products
Abstract
A safety chain circuit includes a plurality of protection devices connected between a first chain end and a second chain end, and an amplifier. The amplifier includes a first device switch and a second device switch connected between an input and an output, a first enabling switch connected between the second chain end and a second enabling switch, and a first control switch and a second control switch. The first enabling switch selectively enables the first control switch to control the first device switch. The second enabling switch selectively enables the second control switch to control the second device switch. The first control switch, when enabled, selectively controls the first device switch in response to receiving a first control signal. The second control switch, when enabled, selectively controls the second device switch in response to receiving a second control signal.
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Citations
20 Claims
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1. A safety chain circuit for use with a control system that provides a first control signal and a second control signal, the safety chain circuit comprising:
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a plurality of protection devices serially connected between a first chain end and a second chain end; and an amplifier including a first device switch and a second device switch serially connected between a power input and a power output, a first enabling switch connected between the second chain end and a second enabling switch, and a first control switch and a second control switch; wherein the first enabling switch is operable to enable the first control switch to control the first device switch, and the second enabling switch is operable to enable the second control switch to control the second device switch; and wherein the enabled first control switch is operable to control the first device switch in response to receiving the first control signal, and the enabled second control switch is operable to control the second device switch in response to receiving the second control signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An elevator system, comprising:
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one or more elevator drive components respectively connected to one or more disconnect switches; an elevator drive control system operable to control one or more elevator drive components, and provide a first control signal and a second control signal; a plurality of elevator protection devices serially connected between a first power source and a chain end; and an amplifier including a first device switch and a second device switch serially connected between a second power source and the one or more disconnect switches, a first enabling switch connected between the chain end and a second enabling switch, and a solid state first control switch and a solid state second control switch; wherein the first enabling switch is operable to enable the first control switch to control the first device switch, and the second enabling switch is operable to enable the second control switch to control the second device switch; and wherein the enabled first control switch is operable to control the first device switch in response to receiving the first control signal, and the enabled second control switch is operable to control the second device switch in response to receiving the second control signal. - View Dependent Claims (17, 18, 19)
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20. An escalator system, comprising:
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one or more escalator drive components respectively connected to one or more disconnect switches; an escalator drive control system operable to control one or more escalator drive components, and provide a first control signal and a second control signal; a plurality of escalator protection devices serially connected between a first power source and a chain end; and an amplifier including a first device switch and a second device switch serially connected between a second power source and the one or more disconnect switches, a first enabling switch connected between the chain end and a second enabling switch, and a solid state first control switch and a solid state second control switch; wherein the first enabling switch is operable to enable the first control switch to control the first device switch, and the second enabling switch is operable to enable the second control switch to control the second device switch; and wherein the enabled first control switch is operable to control the first device switch in response to receiving the first control signal, and the enabled second control switch is operable to control the second device switch in response to receiving the second control signal.
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Specification