Thursday, December 13, 2012

Blast from Bob

Bob gives me an update.  He is doing some interesting work with the car and taking it to the next level:
 I started to talk about the charger issue.  I had contacted the Zivan rep and got a cold shoulder from them.  I designed my own charger and got it working after a few blown transistors.  My goal was 135 volts max and 10 amps max and the charger achieved both of those goals.  The packaging was rather crude because I used a discarded chassis from some unknown piece of electronic gear.  It was so bulky that I was unable to close the hood while charging. Right after I got that thing working well, I stumbled upon the forum called diyelectriccar.  Under the heading about charging, I found other people unable to get Zivan to properly convert their chargers to lithium.  One person actually went to the extent of designing a bug to replace the existing processor.  He was willing to sell copies of this bug so I bought one.  He even included a sample program which he had used for his car.  I don't know much about programming, but since all I had to do was change a few lines of code to match my battery pack, I got the Zivan working for lithium! I put my design aside and just chalked it up to experience.  Another little problem I solved involved the lack of a reliable parking brake.  Using the chocks has been unhandy.  I lost one when I drove off without it.  The solution is a brake club.  Rather than describe it, I'll send a picture.  The club goes between the pedal and the base of the seat.  It goes over center and latches.  Another latch situation came up.  The 12v battery went down to the extent it wouldn't operate the relay to energize the main solenoid.  This is a situation which could leave you stranded.  This relay also connects the DC-DC converter from the main battery to the little one.  The emergency fix for this is to drill a small hole in the the side of the DC relay, turn on the key, and insert a toothpick into the hole against the relay armature and push.  The relay will hold because the small battery is being charged by the big battery.




I hope to get down there and film a ride sometime.  It would be quite a different ride, I think.