Electronic safety circuit for machines - has series connected electronic safety devices activated by differential amplifier to generate machine starting current

摘要

The safety circuit for an industrial machine consists of two identical channels with a number of electronic devices connected in series. These devices are normally non-conducting but become conducting under the effect of an input signal. When a signal is received the differential amplifier is activated and sends a signal to the signal store. A signal from the store is transmitted to a device in onechannel. When all the devices receive input signals, a sufficiently strong current is generated to activate the output devices and to start the machine. a time control device incorporated in the store shuts off the machine at the pre-set time.