Need Help- Configuring Innovate LM-1/2

[surflvr911sc]

I'm trying to log oil press, oil temp, and cht w/ my LM-2 and I need some advice; has anyone else out there already worked this out? SteveW?

Oil Press jumps around at about 4.5 vdc at idle, then maxes out at 5 vdc at higher rpm. Oil temp is a nice useless steady 5 vdc. Do I need to set up a resister or potentiometer to get these to work w/ the 0-5vdc LM-2 limitation? It seems that I would have to if I'm limited to 0-5vdc, and I'm easily maxing those out.

CHT is 0 vdc w/ the occasional spike up to 4 max. This is coming off of a generic VDO CHT kit and I know there is probably something up w/ this.

I'd love to hear from somebody that has btdt, before I reinvent the wheel.

Thanks!

[ischmitz]

Ryan,

When you hook up the input of the LM-2 to the signal wire you end up measuring the voltage drop across the respective sending unit. It can be up to 14.4 volts (onboard voltage). The LM-2 can only sense up to 5 volts. You are maxing out your LM-1, that is why you don't see anything useful. A simple 1:2 voltage divider network will help to spread the input of the LM-2 to 0-15V:

For each chanel get yourself two resistors at radio shack: 10kOhm and 5kOhm. Hook them together. Attache the other end of the 5kOhm to GND and the other end of the 10kOhm to the signal wire of the sensor. Attach the input of the LM-2 to the comon point of the two resistors. You can use cheap 1/4 Watt versions. Voila.....

Sensor------ [ 10k ]--------*-------[ 5k ]-------GND

LM-2 input to the *

Cheers,
Ingo

[surflvr911sc]

Sh|t Hot! Ingo you're awesome! I should have just emailed you in the first place. I'll go grab 'em and report back. Thanks!

[mjshira]

this is an interesting thread, Ryan keep us posted. I've got an LC-1. I am thinking about expanding it though.