Function-supervising device

Abstract

A device ( 1 ) for supervising the function of an electric consumer ( 2 ), such as a heating unit in a road finisher, is connected in a supply circuit ( 3 ) of electrical current of a consumer, and has an induction coil ( 4 ) associated with the current supply to which is connected a circuit ( 6 ) for detecting and indicating a voltage induced in the coil ( 4 ) by the supply current.

1 . A device for supervising the function of an electric consumer, in the form of a heating unit in a road finisher, connected in a supply circuit of electrical current, said device comprising: 
 an induction coil associated with the current supply circuit for the consumer; and    means associated with the induction coil for detecting and indicating a voltage induced in the coil by the supply current.    
   
   
       2 . A device according to  claim 1 , wherein said means for indicating comprise a visual indicator.  
   
   
       3 . A device according to  claim 1 , wherein said means for indicating comprise a light emitting diode.  
   
   
       4 . A device according to  claim 3 , wherein if the electric consumer is operated with alternating electrical current or with a three-phase electrical current, the device further comprises a rectifier circuit in which the light emitting diode is connected.  
   
   
       5 . A device according to  claim 1  wherein said means for detecting and indicating comprises a measuring instrument.  
   
   
       6 . A road finisher comprising: 
 at least one electric heating unit connected in a supply circuit of electrical current and used for heating work components, and a device according to claim for supervising the function of said heating unit.    
   
   
       7 . A road finisher according to  claim 6  wherein said means for indicating according to  claim 1  comprises a visual indicator.  
   
   
       8 . A road finisher according to  claim 3  wherein said means for indicating according to  claim 1  comprises a light emitting diode.