Floor Shifter Light Black Box - Page 2 - DodgeIntrepid.Net Forums - Dodge Intrepid, Concorde, 300m and Eagle Vision chat
Reply
 
LinkBack Thread Tools Rate Thread Display Modes
post #16 of 27 (permalink) Old 11-24-2012, 11:57 AM Thread Starter
Intrepid Modder
 
Join Date: Feb 2009
Location: Cheyenne, WY
Posts: 631
Feedback: 0 / 50%
               
Quote:
Originally Posted by peva View Post
Umm - no. The '12' needs to be '1.2' in my example, but according to the data sheet on your LED's, should be 2.0 (the forward voltage). So that would come out to 590 ohms (or closest value).
I deleted the *, by accident, but it referred to the 12 as 2Vx6 bulbs, which probably would help understand my entire post.

Quote:
For consistent brightness (i.e., 12 volts engine off, 13.8 engine running), you could put an 8 or 10 (preferred) volt regulator in, use 3 LED's, and use the regulator output voltage in place of the 13.8 volts.
Kind of lost here, so let me see if I have it. A 10V regulator is an electrical part, wired before the LED, that would cut the 13.8V down to 10V? Then a 200 ohm resistor would be wired in series between the regulator and LED? So if I have 3 LEDs, it would go regulator, resistor, LED, LED, LED? How would you wire the LEDs, in series, if positive has to match positive in order for the LED to work? Forgive me, I only know the basics of basics of electricity.

Quote:
I could draw it for you, but visualize a cone with its point at the LED die. The total included angle would be the 15, which would be a line at 7.5 from axis (0) swept around to form the 15 included angle" cone.
It helps to see it.. So with a greater viewing angle, you will be able to still see the light, on a tilt, until you reach the max degree and then it disappears? Like on some cell/laptop displays.
BatCaveTrep is offline  
Sponsored Links
Advertisement
 
post #17 of 27 (permalink) Old 11-24-2012, 12:16 PM
Intrepid Pro
 
Join Date: Feb 2002
Location: Virginia, U.S.
Posts: 14,133
Feedback: 4 / 83%
                     
Quote:
Originally Posted by BatCaveTrep View Post
I deleted the *, by accident, but it referred to the 12 as 2Vx6 bulbs, which probably would help understand my entire post.
Ahh OK. But - yes, as you pointed out in that post, you don't want the stack voltage to get too close to the system voltage due to some tolerance of the 2 volts per LED and normal fluctuations in the system voltage.

Quote:
Kind of lost here, so let me see if I have it. A 10V regulator is an electrical part, wired before the LED, that would cut the 13.8V down to 10V?
...*and* also to 10 volts with engine off (i.e., battery at 12 volts), and 10 volts even with normal fluctuations of system voltage - so brightness will always be consistent.

Quote:
...Then a 200 ohm resistor would be wired in series between the regulator and LED?
By Jove - I think you've got it! (10-6)/0.020 = 200

Quote:
So if I have 3 LEDs, it would go regulator, resistor, LED, LED, LED? How would you wire the LEDs, in series, if positive has to match positive in order for the LED to work? Forgive me, I only know the basics of basics of electricity.
In series would be 10V to resistor, resistor to first LED's anode, that LED's cathode to next LED anode, that LED's cathode to the 3rd LED's anode, then the 3rd LED's cathode to ground. It's called daisy chaining - that should help you visualize it.

Quote:
It helps to see it.. So with a greater viewing angle, you will be able to still see the light, on a tilt, until you reach the max degree and then it disappears? Like on some cell/laptop displays.
Yes. It's not a sudden cut off - it's the 1/2 intensity (relative to straight on max. intensity viewing at 0) point, but I believe the cutoff is fairly sharp as you pass thru that 1/2 intensity angle - yes like a laptop screen.


'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs
peva is offline  
post #18 of 27 (permalink) Old 11-25-2012, 10:39 AM Thread Starter
Intrepid Modder
 
Join Date: Feb 2009
Location: Cheyenne, WY
Posts: 631
Feedback: 0 / 50%
               
Quote:
Originally Posted by peva View Post
In series would be 10V to resistor, resistor to first LED's anode, that LED's cathode to next LED anode, that LED's cathode to the 3rd LED's anode, then the 3rd LED's cathode to ground. It's called daisy chaining - that should help you visualize it.
I get it now, but I don't think that will work the way I want it to. Example: 3 LEDs, wired in series for the white color. If I wanted LED #2 to change colors, turn off white and show green, wouldn't it need to be wired seperately, so there is control of the white? You wouldn't be able to turn off white and still provide power to LED #3, would you? If I picture the series, as like bridging with speakers, it wouldn't work. Hopefully the makes sense. So if I am right, wouldn't I need to wire each LED, seperately, and regulate the voltage to 2V, for each, and require no resistor?

Last edited by BatCaveTrep; 11-25-2012 at 10:42 AM.
BatCaveTrep is offline  
post #19 of 27 (permalink) Old 11-25-2012, 11:55 AM
1st Gen FTW - It's AutoMedic!

 
cdmccul's Avatar
 
Join Date: Jun 2008
Location: Garrison, ND
Posts: 15,412
Feedback: 18 / 100%
                     
You always need a resistor (unless you know it is built into the LED).

You can do what you want, you just have to build a switch for every LED. Build the power supply, run the LED set like you want, but the put a relay after the resistor, and before each LED. Wire up LED to the relay such that when the relay flips, it changes what colors are active in the LED.

Then your selection routine drives each relay to change color. Maybe look into solid state switches, they may be faster and help reduce lag and brightness fluctuations.
cdmccul is offline  
post #20 of 27 (permalink) Old 11-25-2012, 12:59 PM
Intrepid Pro
 
Join Date: Feb 2002
Location: Virginia, U.S.
Posts: 14,133
Feedback: 4 / 83%
                     
Quote:
Originally Posted by BatCaveTrep View Post
I get it now, but I don't think that will work the way I want it to. Example: 3 LEDs, wired in series for the white color. If I wanted LED #2 to change colors, turn off white and show green, wouldn't it need to be wired seperately, so there is control of the white? You wouldn't be able to turn off white and still provide power to LED #3, would you? If I picture the series, as like bridging with speakers, it wouldn't work. Hopefully the makes sense.
Yes, you are correct.

Quote:
So if I am right, wouldn't I need to wire each LED, seperately,
Correct up to this point

Quote:
...and regulate the voltage to 2V, for each, and require no resistor?
No. There's a part of this that has not sunk in yet. The LED forward voltage is approximate. It is approximate because, like everything, it has a tolerance, it is temperature sensitive, it changes with current, and it varies from one sample of the same part number LED to another. ALSO - any regulation you do is approximate - for the same reasons on the regulator. If you force a fixed voltage across the LED, the current can vary a lot from minor variations in the LED forward current and the regulated voltage. By putting some distance between the imprecise forward voltage and the imprecise regulator voltage and spanning that difference with a resistor, you greatly reduce the sensitivity of the current to the unavoidable variations in the two voltages. You can build active circuits, called constant-current regulators, to cut that sensitivity to almost zero, but you don't need to go to that extreme. A resistor is a good compromise.

The closer you get the forward LED voltage and the regulator voltage, the smaller the resistor value, and the more variation in the current/brightness/LED life you're going to get (all the way to the unwise and most sensitive situation where you have zero resistance and two varying, relatively imprecise voltages that come together at a single point - when they are forced to the same voltage, the difference between the ideal calculated and the actual current can get large). The trade off is efficiency where you can stack LED's to run multiple LED's off of the same power usage as running a single LED (original supply voltage x current in that string regardless of number of LED's in the string) - the higher you stack and the less the voltage difference, the more efficient you are, but the more current variation you will get with relatively minor voltage variations - hence the advice not to stack more than 4 or 5 volts from the supply voltage (you can get closer if your supply is well regulated).

You can see where putting the regulator in is a big improvement over running straight off of the car's hugely-varying system voltage. But if you're going to run only one LED in a single string, then you might decide that you don't need a regulator - that one higher-value resistor will be "good enough".

You've got to decide what you're going to trade off. You definitely need more than a "fixed" (a relative term - everything has a tolerance and variations over time) voltage across an LED - too many things you don't/can't control (like your car's system voltage and the LED's forward voltage) that are going to give large brightness variation and likely shorten life unless you cut your "nominal" operating current and brightness *way* back to allow for the variations. On the other hand, with one LED, it might be overkill to put in a regulator *and* a resistor - you likely can reasonably decide you can go with just a resistor (but definitely *not* a voltage regulator with no resistor).

To develop insight into those things, you can do the calculations based on certain assumptions for reasonable variations of the parameters. Reasonable conclusions on cars are likely to be that you need a regulator (plus resistor) if you're going to stack more than 2 LED's in a single string. For one or two LED's, you can get by with just a resistor - the most variation you will get is due to the difference between motor running (approx. 13.8 volts) and motor off (approx. 12 volts).


'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs
peva is offline  
post #21 of 27 (permalink) Old 11-25-2012, 05:44 PM Thread Starter
Intrepid Modder
 
Join Date: Feb 2009
Location: Cheyenne, WY
Posts: 631
Feedback: 0 / 50%
               
Quote:
Originally Posted by peva View Post
To develop insight into those things, you can do the calculations based on certain assumptions for reasonable variations of the parameters. Reasonable conclusions on cars are likely to be that you need a regulator (plus resistor) if you're going to stack more than 2 LED's in a single string. For one or two LED's, you can get by with just a resistor - the most variation you will get is due to the difference between motor running (approx. 13.8 volts) and motor off (approx. 12 volts).
So for just one LED I could use a 10V regulator, so there is brightness consistancy, and a 400 ohm resistor. I'm going to sketch up a diagram and see if I am on the right path.
BatCaveTrep is offline  
post #22 of 27 (permalink) Old 11-25-2012, 05:49 PM
Intrepid Pro
 
scarce911's Avatar
 
Join Date: Sep 2007
Location: Van Wert, Ohio
Posts: 1,009
Feedback: 8 / 90%
                     
If you want your led viewing angle wider..sand down the rounded end of the led flat..the sanding marks will diffuse the lighting and make it more even..instead of a focused beam
scarce911 is offline  
post #23 of 27 (permalink) Old 11-26-2012, 10:26 AM Thread Starter
Intrepid Modder
 
Join Date: Feb 2009
Location: Cheyenne, WY
Posts: 631
Feedback: 0 / 50%
               
After looking at the wiring diagrams (8W-40-8), I can't find how the cluster displays what position has been selected. Is it displayed based on voltage?
BatCaveTrep is offline  
post #24 of 27 (permalink) Old 11-26-2012, 12:44 PM
Intrepid Pro
 
Join Date: Feb 2002
Location: Virginia, U.S.
Posts: 14,133
Feedback: 4 / 83%
                     
Quote:
Originally Posted by BatCaveTrep View Post
After looking at the wiring diagrams (8W-40-8), I can't find how the cluster displays what position has been selected. Is it displayed based on voltage?
The range sensor in the transmission is a set of contact closures that the TCM (PCM in '02 and up) decodes to tell the computers what gear the shifter is in. I don't have my books in front of me, but I believe the TCM (or PCM) sends that info. to the BCM, and the BCM sends it to the cluster (all communication done over the PCI bus).
peva is offline  
post #25 of 27 (permalink) Old 11-26-2012, 12:59 PM
1st Gen FTW - It's AutoMedic!

 
cdmccul's Avatar
 
Join Date: Jun 2008
Location: Garrison, ND
Posts: 15,412
Feedback: 18 / 100%
                     
^^^ What he said. ^^^

I have had a plan in mind similar to yours, and it will be done by tapping into the signal going to the solenoid packs - but yes, same concept, you have to see what the range sensor is saying. In a first gen, I could also tap into the power for the display LEDs, since they are not part of a multi-segment display.
cdmccul is offline  
post #26 of 27 (permalink) Old 11-26-2012, 05:35 PM Thread Starter
Intrepid Modder
 
Join Date: Feb 2009
Location: Cheyenne, WY
Posts: 631
Feedback: 0 / 50%
               
Quote:
Originally Posted by peva View Post
The range sensor in the transmission is a set of contact closures that the TCM (PCM in '02 and up) decodes to tell the computers what gear the shifter is in. I don't have my books in front of me, but I believe the TCM (or PCM) sends that info. to the BCM, and the BCM sends it to the cluster (all communication done over the PCI bus).
I understood that, but wasn't sure if the info was sent by a means that could be easily translated for this project. About relays, is there a set number of inputs and outputs allowed? Also when wiring LEDS, seperately (not in series), can you use one resistor or does each LED need its own resistor? Also, is the dimmer voltage base and if so would it affect the input voltage (not a constant 10V)?


Quote:
Originally Posted by cdmccul View Post
In a first gen, I could also tap into the power for the display LEDs, since they are not part of a multi-segment display.
No bragging is allowed. I'm going to hold off on the selection for now, but have an idea that may work.

Last edited by BatCaveTrep; 11-26-2012 at 05:37 PM.
BatCaveTrep is offline  
post #27 of 27 (permalink) Old 11-26-2012, 08:43 PM
Intrepid Pro
 
Join Date: Feb 2002
Location: Virginia, U.S.
Posts: 14,133
Feedback: 4 / 83%
                     
Quote:
Originally Posted by BatCaveTrep View Post
I understood that, but wasn't sure if the info was sent by a means that could be easily translated for this project.
To my knowledge, the PCI bus is a digital data stream with all kinds of data going between the various computers constantly. There may be someone here who knows how to tap into that and read the data, but I sure don't.

Quote:
About relays, is there a set number of inputs and outputs allowed?
A relay has a single coil (the thing that makes the contacts to close and open), but can have one or more contacts (called poles), and the contacts can be single or double throw - most are double throw. If those terms don't mean anything to you, you need to find a tutorial on switches and relays. If several LED's are going to be turned on and off at the same time, then they can all run off the same contact (i.e., wired in parallel).

Quote:
Also when wiring LEDS, seperately (not in series), can you use one resistor or does each LED need its own resistor?
That's the parallel operation I mentioned. Each has to have its own resistor. That's because, as pointed out earlier, they each will have a slightly different forward voltage, so if you feed several with one resistor, the one with the lowest forward voltage will hog most of the current and be brigher than the others.

Quote:
Also, is the dimmer voltage base and if so would it affect the input voltage (not a constant 10V)?
I guess by "base" you mean is it the lower voltage. If so, the answer is yes (at maximum brightness, it would be close to ground to give full voltage across the LED's).

You know - I just realized something, and I must apologize. If you're running these LED's off the dimmer ciruit, you can't use a regulator. You have to go with resistors only. A regulator would only be used for constant brightness - where at any given moment the LED(s) will either be on or off.

So in your sketch, you'd do it like the one on the right (a resistor for each LED) - but leave out the regulator.

Quote:
No bragging is allowed. I'm going to hold off on the selection for now, but have an idea that may work.
Cool! Can't wait to find out what it is.


'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs

Last edited by peva; 11-26-2012 at 08:49 PM.
peva is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the DodgeIntrepid.Net Forums - Dodge Intrepid, Concorde, 300m and Eagle Vision chat forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Member names may only be composed of alpha-numeric characters. (A-Z and 0-9)

!!ATTENTION ADVERTISERS!! If you intend on advertising anything on this forum, whatsoever, you are required to first contact us here . Additionaly, we do NOT allow BUSINESS NAMES unless you are an Authorized Vendor. If you own a business, and want to do sales on this site via posting or private message, you will need to follow the rules. Shops, Stores, Distributors, Group Buys without being authorized will see your account terminated.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome