would it be possible to make my own shift light???

[Chuckt]

would it be possable for my to connect a power wire from the tach to a potentiometer that goes to an led and make it light up depending on what the knob is set at? so basically i can turn the konb so the led lights up at a set rpm?? im just wondering if this will work. Thx

 

[LightningGSX]

Yeah you can make your own, but not that way.

 

[90DSMTurboFWD]

Care to explain how he might make it then? I'm interested as well.

 

[LightningGSX]

I can think of a few ways.You could use a frequency to voltage convertor off the tach wire and a comparator or an op-amp to actuate the light.You could use a microcontroller to count the pulses and actuate a light.Or you could take analog voltage directly from the tachometer itself and use a comparator or an op-amp th actuate the light.I know I could think of a couple more too.

 

[LightningGSX]

Also if you had an eprom ecu, I would imagine you could alter some values and use the egr output or evap purge or something like that to actuate the light.

 

[Chuckt]

is there some kinda very simple diagram you could make cause all that shits over my head hehe

 

[Chuckt]

like what can i jsut slpice into the tach to a led and resistor to make work???

 

[LightningGSX]

I can't think of a "simple" way of doing it.You live somewhat close to me, maybe I can whip something up.

 

[Defiant]

Sounds like for you, probably not. It's not bad if you're an electronics guy who knows how the factory tach is driven, but for you and me, just buy one.

Can't you tell when it's time to shift?

 

[Chuckt]

im now smarter for reading your response, thanks

 

[DSMJim]

Why make a shift light?

Proform makes a great shiftlight that's cheap.

http://www.mustangweekly.com/2001/april/newprdts/NPP40.asp

Here it is on ebay as well.

http://search.ebay.com/search/searc...ight&newu=1&krd=1?keyword=proform+shift+light

I have that same shiftlight installed on my car. WHat I did though was take the bracket off and the two screws that hold the bracket to the body I just screwed the body of the shift light to my dual pod directly from the inside of the pod so it hangs right off the pod with no bracket. It tucks in nicely and just take off the rubber cover at the track and your good to go.

 

[92redman]

I can think of a few ways.You could use a frequency to voltage convertor off the tach wire and a comparator or an op-amp to actuate the light.You could use a microcontroller to count the pulses and actuate a light.Or you could take analog voltage directly from the tachometer itself and use a comparator or an op-amp th actuate the light.I know I could think of a couple more too.

If you don't mind elaborating on this a little further, how exactly would you use an op-amp to turn on the light? Would the light only blink when the correct voltage is reached or will it stay on at any voltage over that point?

Sorry for bringing this back, just trying to understand how to make this work for a custom application. Would rather not use a commercial shift light.

 

[92redman]

http://www.atkinsonelectronics.com/product_pdfs/VRDC.pdf

Would something like that work in conjucntion with a frequency to voltage convertor. I was looking at this one but not too sure:http://www.rbeelectronics.com/re1040.htm

 

[LightningGSX]

If you don't mind elaborating on this a little further, how exactly would you use an op-amp to turn on the light? Would the light only blink when the correct voltage is reached or will it stay on at any voltage over that point?

Sorry for bringing this back, just trying to understand how to make this work for a custom application. Would rather not use a commercial shift light.

Although I wouldn't recommend it(you may have some oscillation around the switch frequency), you can use a op amp as a comparator.A comparator with hysteresis would be a better choice.A V to F convertor will ouptut a voltage based on frequency input, so if you use a comparator, once the threshold voltage is reached(your preset RPM) the light would come on and stay on until below the threshold voltage(preset RPM).Depending on where you get your RPM signal, you may have to use a schmidt trigger(to smooth things out) or a optical isolator(noise protection), and maybe even an op amp(as a voltage follower) to provide high input impedance.

All these parts are extremely cheap(usually less than a dollar), if you have some knowledge of electronics, you should be able to play with some parts and end up with a shift light.

 

[jepherz]

you can use a op amp as a comparator.A comparator with hysteresis would be a better choice.A V to F convertor will ouptut a voltage based on frequency input, so if you use a comparator, once the threshold voltage is reached(your preset RPM) the light would come on and stay on until below the threshold voltage(preset RPM).

The only opamp I am familiar with is the 741. Is there another opamp that you can run off of automotive power (ie. don't need both +12 and -12V). I need to build a small circuit for an autronic ECU, and this would be very helpful.

Thanks Lightning

 

[LightningGSX]

I usually use National Semiconductor parts, they have a fairly large selection of single supply op amps, as well as, a large selection of various components designed specifically for automotive applications. http://www.national.com/appinfo/amps/