System for identifying application of supply voltage esp. for electronic circuit - has identifying unit connected to supply voltage lead for identifying application and interruption of supply voltage across supply voltage lead also signal prodn. unit

摘要

The signal prodn. unit (110) is connected with the identifying unit (100), and reacts to this, to produce a signal which indicates the application of the supply voltage. The signal prodn. unit includes inverter circuits (111,112), which form an interlocking system. The input of which is connected to the output of the identifying unit (100). The system also includes a control unit (120), which matches the driving capabilities of the inverter circuits with switching on and switching off. Alternatively an activation control circuit delays the activating point. This circuit activates a signal generator circuit (110) to the time, at which the potential of the output junction (ND10) of the identifying circuit rises above that of the output junction (ND15) of the signal generator circuit. ADVANTAGE - Switch on identifying signal is reliably produced, uninfluenced by residual charges produced by switch off.