Oz DIY-WB Wiring Diagram

Oz DIY-WB Wiring Diagrams

These notes describe how the Oz DIY-WB PCB is connected to other components to complete a wide band exhaust gas oxygen content meter (or EGO meter). We will add extra components that we have in development as they are completed

Wide Band EGO Meter - System Overview

Output from the Oz DIY-WB PCB may go direct to the 5300 Display (also known as The Modified FMD unit). The WB output may also be split off at CON3 to go to an analogue data logger (Vout is 1.4 -> 3.1 Volts).

Power (positive voltage from the vehicle's electrical system) and ground is supplied to the PCB, the sensor, and the 5300 display via CON2.

The NTK UEGO sensor connects to the Oz DIY-WB PCB at CON1. The sensor's (male) Sumitomo connector also holds the sensor's calibration resistor (CalR).

An optional RS232 output from the 5300 display is available for connection to a PC or low speed serial data logger.

Note that a wire link must be installed on the WB PCB to supply battery power to CON3.

System Interconnections

The sensor connector CON1 goes to the NTK sensor's special male Sumitomo connector with the calibration resistor (CalR) in the connector shell itself. Only the heater wires need to be heavy duty cable to ensure very low voltage drop. The sensor's Nernst Cell wires, as well as the CalR wires carry only small currents and they need only small gauge wires, and it's better to use shielded 4 core cable (CON1-pin2 to the shield).

Connector CON2 should be connected to power via an inline 5 Amp fuse if an unfused connection point is selected. Remember that the power/ground wires should be reasonably heavy gauge to ensure low voltage drop to the WB PCB, and the connection points should be close to the battery to prevent regulator voltage drop-out.

Connector CON3 (a DB9) carries the PCB's Vout signal, and goes to the 5300 display. By adding a wire link on the WB PCB (see bleow), it is possible to supply the display with power and ground. This simplifies the display's wiring. The latest TE-5300 kits include a DB9 and an appropriate two conductor shielded cable (shield goes to ground).

Colours shown above are either from the
NTK sensor, or are suggested schemes.

5300 Display Connection

The image at left shows the very small modification required to connect the 5300 display directly to the DIY-WB PCB. This supplies 12 Volt (battery) power to the display via the male (DB9P) connector (a PCB mount DB9P is not supplied in the parts kit).

On the underside of the DIY-WB PCB add a wire from CON3 pin 9 to CON2 pin 1. If you use a small diameter wire (wire wrap wire is shown) it will also act as a fairly low current fuse should the external wiring to the 5300 display short.

Optional RS232 from the 5300 display

If the optional RS232 modifications are made to the 5300 display, then just two wires are required (from the 5300 processor PCB) to connect to a female DB9S connector (a DB9S is supplied with the TE-5300 kit). The DB9S may then be connected to a laptop for mobile data logging. The format of the data is a single binary 8 bit byte at 19.2 k baud (no parity) representing AFR times 10, such that a value of 147 is equivilant to an AFR of 14.7 : 1.

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Last updated 27 February 2002 | Tell me about broken links

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