Patent ID: 7129710
Filing Date: 2006-10-31
Classification: H05K

Abstract:
1. A printed circuit card, comprising: a printed circuit card body made of plastic; a carbonization sensor for protection against smoldering electrical fires disposed on said printed circuit card body, said carbonization sensor having a first conductor track and a second conductor track disposed on said printed circuit card body, said first and second conductor tracks being electrically insulated from one another by said plastic, said first and second conductor tracks forming and defining a capacitor; a monitoring device connected to said carbonization sensor and having a detector circuit, said monitoring device monitoring an insulating state of said first and second conductor tracks in relation to one another and producing a fault signal if the insulating state is violated; and a transformer having an inductance and connected to said detector circuit, said first and second conductor tracks and said inductance of said transformer forming an oscillating circuit being excited by said transformer through said detector circuit, an oscillating behavior of said oscillating circuit being detected by said detector circuit, said detector circuit generating the fault signal when oscillation breaks off.