China made Electronic ignition

Just got the package from the China Vendor. He had also wrote a long letter to me.

The thing is a modified Bosch 009 Distributor with 8 sets of new modified electronic ignition.

The new electronic ignition system is even bigger then the petronix ignitor.

The casing of the distributor needed to drill 2 holes to fasten the bigger electronics and heat sink.

IMG-20150114-WA0000 IMG-20150114-WA0002


Semi-finished tachometer

Additional mod to the tach:

1. Added ST L7812 voltage regulator to the circuit. Stabilize the input voltage to 12V

2. Added a 220uF cap on the regulator output.

3. Cleaned and assembled


Test will be carried out on weekend on my VWs.


PCB replacement and calibration

IMG_20131009_102802 IMG_20131009_102844 IMG_20131009_113849 IMG_20131009_113958 IMG_20131009_114017

Circuit check on ’72 Porsche 914 VDO Tach

Found the circuit schematic from Internet. it is somehow different version as our tach. but the basic concept is the same:

Checking detail:

  • 7W Z1 Zener diode ouput 7.1 V … okay , working
  • 3 transistors BSX68 … okay, de-soldered and checked
  • 3 IN4148 diode,… okay, checked working
  • 3 capacitors de-soldered.. checked okay, some leaking and weaken capacitance, but still working

Spare transistor parts: BSX68 is a 40 years old transistor. Common replacement is NPN 2n3904 that I have a few at home.


IMG_20130918_104830Β  IMG_20130918_104753

IMG_20130918_105054 IMG_20130918_104548

Repairing the 70s Porsche VDO Tach


This is the precise Signal Generator from my company Lab.

Technicians claimed it worth twenty thousand HKD back 10 yrs ago.

I tried 10v to 14v square wave, range 1khz to 10khz. No response. πŸ™

Then tried to put a 3v DC across the pointer rotor motor. ItΒ  turns. πŸ™‚

Ignition MOFET IC arrived

Got another shipment from Element14 (Farnell). This IC will be put on the ignition sub circuit.

Some more soldering