P1: Nitrous at Balls in '08

Hybrid Launch Control

Last Update, 11/3/07 by Stephen Daniel

Break Out Box Design Notes

This page contains random notes we wanted to save on the design of the break-out box.

Notes on the Schematics

• LED channel indicator
  • LSDiodes 5mm T1-3/4 Green
  • 3.3V 20mA nominal
• Calculating the limiting resistor for the indicator diode:
  • 1N4148 @ 20mA has a 1.0V forward drop
  • 8V supply
  • MOSFET = IRF3709 has a negligible on-voltage drop
  • LED + diode have 4.3V forward drop
  • need 3.7V resistor drop
    R=V/I R = 3.7/0.020 = 185 Ohm
    Using actual 200 Ohm
• Jumper wires are 12 gauge (These are used for a number of high-current internal connections on the PCB)
• 16AWG wire for high-current connectors (Wires from the PCB to the high-current connectors.)

Cable and Connector Pinouts

• Signal Cable Pinout
  

  The signal cable connector is designed for a 9-wire cable. We've wired it with a cat-5 cable (4 twisted pairs). We've left channel 5 unwired as a result.

  Pin	Signal	Color
  1	+8 V	blue/w
  2	ch 0	blue
  3	ch 1	o/w
  4	ch 2	o
  5	ch 3	br/w
  6	ch 4	br
  7	ch 5	N/C
  8	ch 6	g/w
  9	gnd	g

• Solenoid Cable Pinout

  The solenoid cable is a simple two-wire power cable. The + wire is connected (through a fuse) to the positive supply voltage. The Vsw signal is switched by a power MOSFET to ground.

  Pin	Signal
  1	V+
  2	Vsw

• Power Cable Pinout

  The power cable is designed to conform to the solenoid cables. Thus solenoids can be tested by simply connecting the power cable to a solenoid cable, bypassing the break-out box.

  Pin	Signal
  1	V+
  2	gnd