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Farshid Jafari Harandi
12/18/05 08:45
Read: 721 times
Sweden
Gothenburg


 
#105499 - Condenser
Responding to: Kai Klaas's previous message
The newer transistorized ignition systems, where a special zener protected transistor is used as interrupter, provide an ignition voltage of about 35kV. Not only this high voltage is dangerous, but also the much higher currents, that can flow.
These ignition systems can be dangerous and harmful!! Take care!!!

I'll take more care , those times that it hit me was by accident.Now, After servicing the Ignition system it even bites if you place your hand around the wires !
Yes,35mm was the maximum distance that i could get a spark.
This would be Off-Topic but since this is in General Chat I ask it.I appreciate If you have the time to answer it :
There is a condenser (a .25uf Capacitor) with it's lead connected to the transistor and GND.
+12(Ignition key)-> ^^^Coil^^^ -> Transistor -> GND
                 |__Condenser___|

I've read three articles on the reason why there is such a capacitor here .They said placing the cap helps to make better sparks due to the LC characteristics which it makes and it also suppresses generated noises.
By opening some of these Axial Capacitors I find out that this a Electrolytic Capaitor.There is no Voltage rating on the ones I've seen.I could guess they should be atleast 25V(Back EMF?).Standard Condesners for my Chevy have 1cm diameter and about 2.5cm height.A .25uf 25V capacitor is way smaller than this.Where is the hint ?

Also, when the battery is discharged and the engine is cranked, battery voltage and by this ignition voltage can dramatically break down

Yes, These HEI's fire easily even in cold weather.In last summer I've installed a second battery.Coil was fed by the cathode of two diodes.Two different batteries were conntected to the different anodes.Second battery still exists.It serves my Car's computer Switching power supply when carnking.

By the way, there's a very simple and nice methode to check, whether the isolation of ignition cables is proper: Start the motor and have a look at the ignition cables, but do it in total darkness.

My father always tells a story about this.He says one day about 25 years ago his vehicle's engine wasn't running alright and an experienced mechanic told him to do what you said.That night my father did it and voila he found a christmas lighting under the hood.He solved the probelm by changing the Spark Wires.

Stay well, dear Farshid,

Thanks dear Kai,
Best Regards :
Farshid

List of 73 messages in thread
TopicAuthorDate
What do you guess it could be ?      Farshid Jafari Harandi      12/16/05 14:14      
   Van Der Graaff generator?      Andy Neil      12/16/05 14:27      
      Whimshurst      Farshid Jafari Harandi      12/16/05 19:08      
   Gas light      Steve M. Taylor      12/16/05 15:58      
   Sparking plug?      Kai Klaas      12/16/05 18:11      
      That's it !      Farshid Jafari Harandi      12/17/05 08:33      
         Very well dangerous...      Kai Klaas      12/18/05 07:26      
            Condenser      Farshid Jafari Harandi      12/18/05 08:45      
               Electrolytic, really?        Kai Klaas      12/19/05 10:43      
                  RE : Electrolytic, really?      Farshid Jafari Harandi      12/19/05 15:36      
                  Could my modifications be harmful ?      Farshid Jafari Harandi      12/21/05 05:41      
                     Capacitors      Steve M. Taylor      12/21/05 05:49      
                        it's always in my sight ;)      Farshid Jafari Harandi      12/21/05 09:21      
                     DCCS      Farshid Jafari Harandi      12/21/05 09:25      
                        So      Steve M. Taylor      12/21/05 10:34      
                           Specifications      Farshid Jafari Harandi      12/21/05 14:10      
                              dash      Steve M. Taylor      12/21/05 14:55      
                                 Box and remote starting      Farshid Jafari Harandi      12/21/05 22:10      
                                 Vacuum forming      Farshid Jafari Harandi      12/22/05 14:44      
                              Plastic Boxes      Jon Ledbetter      12/21/05 15:52      
                                 potting boxes      Farshid Jafari Harandi      12/21/05 22:16      
                                 Potting Boxes?      Farshid Jafari Harandi      12/22/05 14:43      
                                    Vacuum Forming      Jon Ledbetter      12/22/05 15:18      
                                       Thanks for the link      Farshid Jafari Harandi      12/22/05 15:31      
                                          Still need a nice "front"      Steve M. Taylor      12/22/05 16:52      
                                             Casing...      Farshid Jafari Harandi      12/23/05 04:56      
                                                display      Steve M. Taylor      12/23/05 09:38      
                                                   Hidden until light up      Farshid Jafari Harandi      12/23/05 11:10      
                                                      Visiting Tehran      Steve M. Taylor      12/23/05 11:17      
                                                         mail ?      Farshid Jafari Harandi      12/23/05 11:29      
                                    Laptop      Steve M. Taylor      12/23/05 03:11      
                                       Hmm...      Farshid Jafari Harandi      12/23/05 05:17      
                        Dash      Jon Ledbetter      12/21/05 10:53      
                           ...nor      Steve M. Taylor      12/21/05 11:08      
                           Covering is hard      Farshid Jafari Harandi      12/21/05 14:02      
                     Battery seems to be disconnected!      Kai Klaas      12/21/05 09:45      
                        blocking      Steve M. Taylor      12/21/05 10:37      
                        Electrical sytem      Farshid Jafari Harandi      12/21/05 14:01      
                           As I suspected...      Kai Klaas      12/22/05 07:46      
                              How to connect the second battery      Farshid Jafari Harandi      12/22/05 09:50      
                                 Err      Steve M. Taylor      12/22/05 10:22      
                                    Dual battery      Farshid Jafari Harandi      12/22/05 13:06      
                                       OOOPS      Steve M. Taylor      12/22/05 13:17      
                                 You could try this      Kai Klaas      12/22/05 18:31      
                                    RE :You could try this      Farshid Jafari Harandi      12/23/05 05:19      
                        Electrical sytem      Farshid Jafari Harandi      12/21/05 14:03      
            Neat trick      Steve M. Taylor      12/19/05 12:30      
               arcing cables      Terry Lingle      12/19/05 12:57      
                  no way      Steve M. Taylor      12/19/05 14:18      
                  Wow !      Farshid Jafari Harandi      12/19/05 15:38      
                     50,000 volts        Terry Lingle      12/19/05 22:49      
                     Switching techniques      Andy Neil      12/22/05 20:45      
                        Per Plug ?      Steve M. Taylor      12/23/05 03:10      
                           Sort of      Andy Neil      12/23/05 18:38      
                        New techniques      Farshid Jafari Harandi      12/23/05 04:55      
                           Current techniques      Andy Neil      12/23/05 18:44      
                              DC/DC Converter not dedicated coils      Farshid Jafari Harandi      12/23/05 20:54      
                           Ferrari 348      Kai Klaas      12/23/05 19:13      
                              Distributor-less      Farshid Jafari Harandi      12/23/05 20:54      
                                 Not quite      Kai Klaas      12/24/05 06:00      
                                    Look here      Kai Klaas      12/24/05 06:16      
                                       Coils      Farshid Jafari Harandi      12/25/05 01:28      
                                 Distributor-less      Andy Neil      12/24/05 06:16      
                                    Wear and tear      Kai Klaas      12/24/05 06:41      
                                       Amazing      Steve M. Taylor      12/24/05 11:58      
                                    Distributor      Farshid Jafari Harandi      12/25/05 01:28      
                                       Electrical field strengths would be huge      Kai Klaas      12/25/05 06:05      
                                          Big 'uns.      Steve M. Taylor      12/25/05 14:22      
                                             Interesting      Farshid Jafari Harandi      12/25/05 20:57      
                                                Hate to think      Steve M. Taylor      12/26/05 06:10      
                  Porosity of cables      Kai Klaas      12/21/05 09:19      
                     corona      Steve M. Taylor      12/21/05 13:54      
                        Ah, that's the right word.      Kai Klaas      12/22/05 07:14      

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