| ??? 05/11/06 17:27 Modified: 05/11/06 17:41 Read: times |
#116006 - More thought Responding to: ???'s previous message |
Kai Klaas said:
Ok, think about what happens if Mahmood decides not to connect the chassis to the battery. Then he must connect every modul, from the lowest current sensor application to the hihgest current stuff star point like to the ground terminal of battery. But when he must connect the moduls to each other, then every additional connection will form a ground loop. Or, he might want not to connect ground from module A to module B and to open the shield at one side of the cables? Finally he ends with a set-up, where hugh complex impedances of the whole ground routing will make his filtering efforts to become unpredictable or even to crash, where, if once an optimum routing and shielding scheme having found, everything turns bad again if he only wants to add one single additional modul. He can be lucky with this methode, but how much time will he need to find the optimum wiring scheme and how much copper he will need to bury into the car... Thats all fine Dear Kai but I'm solving this problem by installing DC/DC converter in every module connected to my car (or TRUCK) lets say. This way I avoid all the gnd loops problems. I will connect each isolated gnd to battery gnd by 100 kOhm resistor say to stop static building up between two gnds. And as if this would not be enough, he has to deal with a modulated 400MHz application, which cries for the use of a reference plane and the use of shielded cables with the shield connected to GND at both sides!!! How shall he connect the modules without ending with complex impedances of the whole ground routing? How will he force the 400MHz application not to turn the whole car into a paradise for electromagnetic waves of all kind??? Kai No thats another crazy communication project I'm working on and has nothing to do with gnd of vehicles. I just mentioned it here because it looks relevant to the subject. I face many problems with it and very strange behaviours which are atracting my attention for exploration. I never thought ever I will be dealing with sigma - delta modulation and comb filters. The wind keeps blowing in unpredictable directions all the times, so I have to be prepared. I'm crazy and even love that song that says "isn't that craaaaazzzy" I don't know the name of the lady who sings it or the name of the song. If anyone knows please tell me to get it. Mahmood |
