Description

The new connector configuration allows the connectors to handle the current in the automotive environment. Inputs are wired in one connector and the outputs to another connector. We designed an adaptor board to connect the commercial connectors Mini-Fit Jnr to the megasquirt board. This adaptor has up to 4 coil driver or any pin compatible mosfet driver. No more prototyping in the proto area for drivers added. The VB921 empty holes can be replace with multipurpose drivers for VVT, Boost control valve, water injection valve, PWM idle control or any solenoids.

The connector pins can now handle much more current than the old DB-37 computer connector. Remember the coils and injectors carry lot of current. A defect db-37 pin ll lean a cylinder or lower spark-plug power and make the engine run bad or even blow a piston.

The resistors for drivers are inboard. Some pads has been added for direct acces to the input and output pins.

The board has 30 pins. 14 pins for inputs and 16 pins for outputs. See the following.

• 4 IAC (X11 to X14) pins connected to the megasquirt board.
• 4 Spark output or any power output spare pins
• 4 injector driver pins (diver 1 and driver 2)
• 1 power mosfet output (Q16). Coil driver as a basic unit or pwm power output. Mostly use for PWM idle.
• 4 input spare pins (spare1-spare4)
• Sensor input pins and shieled pin.
• Sensor ground

  The board installed on the megasquirt board here.

Assembly

The adaptor board can be assembled or you can do it yourself with the adaptor board kit. The kit included 14 pins pcb header with cable connector and crimp pins, 16 pins pcb header with cable connector and crimp pins.

First, install the pins rail

• Here the part list. First install the pins rail.
• Cut the header pin rail in 2 pack rail and one 3 pack rail. See
• Insert the pins in the PCB footprint's adaptor board. Adjust the pin spacing to help the adatpor board to fit in the db-37 footprint.
• Install the adaptor board into the db-37 footprint for pin solder on the adaptor side. DONT solder the adaptor board to the megasquirt board yet.
• Push the offset pins into the megasquirt board. Pins aligned.
• Solder the pins. Dont over load the solders. See the job done here.
• Remove the adaptor board from the megasquirt board for header installtion next.

Second, install the mini-fit pcb header.

• Cut the holder plastic foot on both pcb headers. Cut the extra lenght pins.
• Install the pcb header in the adaptor board
• Solder 2 pins and check the alignement then solder all off them. Cut the extra lenght under the board if not done before soldered. Clean the board with flux cleaner. See the job done here.
• Now your ready to install the completed adaptor board in the db-37 footprint's megasquirt. Solder 4 corners first, check the enlignement and then cut the extra lenght from each rail pins. Solder the left pins. Clean the board with flux cleaner.
• You are ready to install drivers.

Installation

Insert the assembled adaptor board into the V3 or V3.57 DB-37 footprint. If the megasquirt board is already populated you ll need to remove the parts under the adaptor board area and solder them under the board. Move the MAP sensor on TOP.

V3

TOP :Relocate the following part under the board here:R30,R31,R32,R16,D4,D8,D10,D11,D12,D19,C15,C3,MOV1,F2,R43,Q14,Q10.

Bottom : Relocate the following part on the top of the board here: MAP sensor

V3.57

TOP :There is no need to move parts on the V3.57 but D22 is the flyback diode for the fidle output. Some prefere to remove it and relocate it under the board to the DB-37 #30 and #26(12V) here.

Bottom : Relocate the following part on the top of the board here: MAP sensor.

Connections

• 4 IAC (X11 to X14) pins connected to the megasquirt board.
• 4 Spark output or any power output spare pins
• 4 injector driver pins (diver 1 and driver 2)
• 1 power mosfet output (Q16). Coil driver as a basic unit or pwm power output. mostly use for BOOST
• 4 input spare pins (spare1-spare4)
• Sensor input pins and shieled pin.
• Sensor ground

  Here the connector side pin identification. Here the PCB foot print with parts location and here the 4 coil dirver.

The board installed on the megasquirt board and the finished nice setup

Panel

Low profile red box enclosure with black anodized and laser cutted enplates.

Applications