摘要 |
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. |