ecu voltage problem

[Sandy]

At 08:13 PM 4/30/97 -0700, you wrote:
>When we hook up the 6V radio shack supply we connect it directly to the
>ground and power lines on the board, thereby bypassing the Voltage
>regulator altogether. However the board has worked on an engine mounted on
>the stand using the voltage regulator and the 12 volt batteries.  
>
>I always thought 1 ms was awfully slow as well but the engine actually
>idles with the 1ms event times at the injectors, very lean I suspect, but
>running none the less.  The MCU is putting the 1 ms pulses on the pins of
>the 1949's but the 1949's don't even get to hold state with that little
>time.  

1ms may be too short to see the effects of the hold state. I can't remeber
off hand what it looked like on the scope when I tried it with low
impedance injectors (~2ohm). You can also see what the feedback voltage is
doing by looking on the sense pin of the lm1949, if it is not getting to
385mv, then it won't trip to the hold state. Check the Lm1949 data sheet.

[snip]


Sandy