In the image above simply click on the chip location for more information.


Download Equivalent Schematic for Eagle-Cad (L1A-L2A.sch)


The above schematic contains all 8 driver signals. This has been grouped together to make it easier to see the operation of MASTER_ENABLE. The host micro-controller (68HC11A8) converts the serial pulse-width modulated FD signal into 8 parallel injector driver signals. As can be seen MASTER_ENABLE controls all the injector signals. If this signal is false no injector may operate regardless of what the host micro-controller commands. Thus it is very important to understand the operation of this signal.

<<Go Back to Chip Location Reference


<<Back to Chip Ref Main

IDM MOD HOME

Next Chip>>

L1, 74HC08 Quad 2-input AND gate

Pin #

Pin Description

Circuit Configuration

IDM Function

1

Gate #1 input

Driven by (L15-P6) Connected with (L1-P4,9,12) (L2-P1,4,9,12)

Master Enable

2

Gate #1 input

Driven by (L8-P38)

Fuel Injector 4 Signal

3

Gate #1 output

Sink Driver Output

Fuel Injector 4

4

Gate #2 input

Driven by (L15-P6) Connected with (L1-P1,9,12) (L2-P1,4,9,12)

Master Enable

5

Gate #2 input

Driven by (L8-P36)

Fuel Injector 6 Signal

6

Gate #2 output

Sink Driver Output

Fuel Injector 6

7

GND

Common Ground

Power GND for device

8

Gate #3 output

Sink Driver Output

Fuel Injector 1

9

Gate #3 input

Driven by (L15-P6) Connected with (L1-P1,4,12) (L2-P1,4,9,12)

Master Enable

10

Gate #3 input

Driven by (L8-P42)

Fuel Injector 1 Signal

11

Gate #4 output

Sink Driver Output

Fuel Injector 7

12

Gate #4 input

Driven by (L15-P6) Connected with (L1-P1,4,9) (L2-P1,4,9,12)

Master Enable

13

Gate #4 input

Driven by (L8-P40)

Fuel Injector 7 Signal

14

VCC

Common 5 VDC

Power 5VDC for device

<<Back to Chip Ref Main

IDM MOD HOME

Next Chip>>