Motorsports Village
http://motorsportsvillage.com/forum/

LM2 Analog 1 input
http://motorsportsvillage.com/forum/viewtopic.php?f=7&t=9855
Page 1 of 1

Author:  Slowpoke [ Sun Jan 06, 2013 1:36 pm ]
Post subject:  LM2 Analog 1 input

Anyone know if the input is protected on the LM2 Analog 1 input to over 14 volts like the DL32? I'm wanting to log transbrake release.

Thanks,

Author:  Beretta [ Sun Jan 06, 2013 3:37 pm ]
Post subject:  Re: LM2 Analog 1 input

You telling us that that car is ready for some runs this year =; =; \:D/

Author:  Ken0069 [ Sun Jan 06, 2013 5:57 pm ]
Post subject:  Re: LM2 Analog 1 input

I guess it depends on what you mean by "that car"? :-k

Author:  Slowpoke [ Sun Jan 06, 2013 6:32 pm ]
Post subject:  Re: LM2 Analog 1 input

Sorry, the real race car is on hold. I'm running my old street car that I bracket raced back in the 90's.

It's going to be my slow bracket car for a while till I have the time to finish the other Nova.

It's also a 69 Nova with a smaller engine, 427 big block that came out of a 4 wheel drive double cab 1 ton flatbed dually. Last time the Nova was at the track in 1998, and it ran 12.10 @ 114 with slicks no exhaust, a small TRW hydraulic cam and about 200 pounds lighter than now (no stock seats, just a fiberglass seat). It's been in storage since then.

I changed the cam and carb and ran it last Saturday with interior, full exhaust, street tires @ 3650 lbs on pump gas and ran a best of 11.64 @ 115. I put in a delay box, an electric shifter and the LM2. Now I can at least practice, I hadn't been down the track in about 3 years. 11's felt pretty good after being away from driving that long! It doesn't need to be any faster, just consistent. I want to keep it streetable.

I'm going to build an E85 Dominator for it and try racing on the cheap for a while.

Author:  shrinker [ Sun Jan 06, 2013 7:41 pm ]
Post subject:  Re: LM2 Analog 1 input

The analog inputs are for 0 to 5 volt only.

Author:  Ken0069 [ Sun Jan 06, 2013 8:41 pm ]
Post subject:  Re: LM2 Analog 1 input

shrinker wrote:
The analog inputs are for 0 to 5 volt only.


So how about a resister to drop that voltage to something below 5v then? :-k

Author:  shrinker [ Sun Jan 06, 2013 11:42 pm ]
Post subject:  Re: LM2 Analog 1 input

That would work; but also install a diode because when the trans-brake solenoid releases there is a backward voltage that can go very high. Even with a resistor it might exceed it on the back voltage. By the way the back EMF (that's what its officially called) causes disruption to other electronics on race cars especially ignitions. It's good practice to also use a flyback diode(thats what it's officially called) on any solenoid.

Although the manual doesnt tell the tolerance of the analogue inputs for this model; throughout the innovate products there is a generality that inputs that are 0 to 5v can only be used for 0 to 5v data logging like variable signals. Things like movement sensors, potentiometers etc. Where as the inputs that are 12 volt for use in switching applications etc are tolerant up to a range of 24 to even 48 volt on some models.

Author:  Slowpoke [ Mon Jan 07, 2013 12:27 am ]
Post subject:  Re: LM2 Analog 1 input

Thanks, I think I logged my transbrake on the DL32 as 12 volts and it just went to the top of the graph. It seems like it was protected to 40 volts but would only read 5 volts.

Anyway, I put a zener diode and a resister that knocked it down to 4.7 volts and all is good.

Thanks again,

Author:  shrinker [ Mon Jan 07, 2013 2:50 am ]
Post subject:  Re: LM2 Analog 1 input

You've done good, that's the safe way. The DL-32 was specified with over voltage protection but cant find it for the LM-2 so what you've done is the best thing.
I note that the DL-32 is not available anymore. They have this pocket logger thing. The DL-32 was a rock solid item from my experience with it, so I'm going to buy one of these pocket recorders to see how good they are and there cheap too. At least they have better connectors now as well.

Author:  Beretta [ Mon Jan 07, 2013 11:19 am ]
Post subject:  Re: LM2 Analog 1 input

Donee, Radio Shack part # 276-1143 diode between the pos/neg wires on the TB will take
care of the noise on release of the TB..Make sure you put it on in the correct flow direction..

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/