schaltungsanordnung to monitor meßkreisen on line break

摘要

It is intended to create a circuit arrangement which, using simple means, confirms the fracture of measurement leads which are isolated in DC terms from a measurement evaluation device. For this purpose, test currents (Ip+, Ip_) are passed during a test phase via the supply leads (L11, L12; L21, L22...Ln1, Ln2) to the measurement transmitters (MWG1, MWG2...MWGn). These currents flow via the input circuits of optocouplers (OK1, OK2). Their output circuits are connected in series so that, if a test current fails as a result of a lead fracture, an alarm signal characterising this state is emitted. The invention is used in analog-value detection systems. IMAGE