OT: Sequencer to illuminate high wattage bulbs

[nirvanas silence]

For anyone that remembers a recent thread I made, I am trying to make sequential taillights for my car and I have the sequencing part ready.  I'm actually going to get a ramping 555 timer circuit so it looks better, but thats another time.  Right now I am having trouble making the LM3914 chip to light the bulb.  I plan on using a ULN2001 chip which is NPN darlington pairs to drive the bulb, but I'm not sure if thats the best way or how to wire it up.  The first link below if the schematic I am using, and the second one is a similar one that uses the ULN2001 chip to light taillight bulbs.  Thanks


http://www3.telus.net/chemelec/Projects/Knight/Knight-Rider-Lights.jpg

http://www.charlton.vic.edu.au/mark/electronics/555_projects/k-rider.html

[nirvanas silence]

Anyone?

[niftydog]

it might work ok, but I thnk you're best bet is to use the ULN2001 to drive relays to switch the full available power to the bulb. Automotive relays are a dime a dozen if you're willing to strip them off cars in a wrecking yard!

The problem is that that ULN2001 has a limit to how much current it can sink, and therefore how much power it will dissipate. You may be limiting the brightness of your bulbs using this method.

...still could be a two IC, four relay, fully customisable solution... don't be scared of microcontrollers folks, they're easy when you know how!

[nirvanas silence]

Well if I use a DPDT relay I can light each side up at once, saving the need for a second LM3914.  Can the LM3914 power a relay?  If not... how would I hook up the ULN2001?  I am confused becuase the LM3914 has the LEDs always hooked up to V+ and the 4017 has them always hooked up to ground.  So negatively triggered and positively triggered?

[niftydog]

Well if I use a DPDT relay I can light each side up at once

yes, but there is then no way of turning ALL the lamps off.

Can the LM3914 power a relay?

No. Relays require more current than the 3914 can sink/source.

how would I hook up the ULN2001?

pin 8 = ground
pin 9 = supply volts (12V from your car I guess.)

Then, the switching outputs of whichever chip you use connect to the inputs of the 2001 (pins 1-7).

Now, connect one side of a relay coil / lamp to 12V and the other side to the corresponding output of the 2001 (pins 10-16). Repeat for all other relays/lamps.

The outputs are opposite of their corresponiding input.

I am confused becuase the LM3914 has the LEDs always hooked up to V+ and the 4017 has them always hooked up to ground. So negatively triggered and positively triggered?

er, well... sort of on the right track.

the LM3914 is SINKING the current for the LEDs. Meaning, the current is flowing through the LED INTO the 3914.

The 4017 is SOURCING the current for the LEDs. meaning the current is flowing FROM the 4017, through the LEDs to ground.

I beleive they have the 4017 configured like that so as to get the proper effect. If the LEDs were reversed, the chaser sequence would be "LEDs turning OFF in sequence" rather than "LEDs turning on in sequence".

Put simply, in the 3914 circuit, an output needs to be LOW to turn on an LED. In the 4017 circuit, an output needs to be HIGH to turn on a LED.


PS; that last sentence, does that read right? What is it about "an LED" and "a LED" that never sounds right?!?!

[nirvanas silence]

You cleared up ALOT!  Thanks a ton.  And what I was mentioning above is DPDT N.O. relays.  So I can do the left and right bulbs in the sequence at the same time.  SO I can go [4][3][2][1][    ][1][2][3][4] if you follow.  Would that work?

[Ge_Whiz]

Mr Nifty, your English is correct. An abbreviation or acronym should always be treated as if it is being read out in full - hence "a Light Emitting Diode (a LED)", "a Stamped, Addressed Envelope (a SAE)", but "an Unidentified Flying Object (an UFO)".

We try to be educational as well as entertaining...  

[Nasse]

http://www.spelektroniikka.fi/kuvat/tehojono.pdf

This is an application that uses power fets

The circuit is not what you asked but the fet idea might be worth thinkin for car use

But if you surf to spelektroniikka.fi ---> kytkiksiä youll find some circuits with ready made pcb patterns that might be useful (some 3914 applications)

[nirvanas silence]

I'm thinking relays may be the way to go to avoid excessive wiring.  Thanks for the links though.

[Tony Forestiere]

GE_WIZ wrote:

Mr Nifty, your English is correct. An abbreviation or acronym should always be treated as if it is being read out in full - hence "a Light Emitting Diode (a LED)", "a Stamped, Addressed Envelope (a SAE)", but "an Unidentified Flying Object (an UFO)".

Nice try, but you used the term "Light Emitting Diode". If that is the case, the article "a" would be correct because the word "light" begins with a consonant sound. <a light emiting diode> Phonetically, the acronym for that device is "el ee dee" beginning with a soft vowel, hence wanting the article "an".<an LED>  :wink:

Unfortunately, your UFO example demonstrates the inconsistancies of the English language!!! :oops: "unidentified flying object" demands the article "an" by virtue of the soft vowel "u", whereas "UFO"<yu ef oh> has that pesky "Y" consonent/vowel rule that has no rule! The correct usage is "an unidentified flying object> and <a ufo>.  :roll:

BTW, "inconsistant" and "inconsistent" are both proper spellings. [No wonder non-english speaking (and even those that do :shock:), have difficulty with the rules of grammar!]

[nirvanas silence]

Agreed.  To sum it up, you go with the way the acronym sounds, not how the spelt out version sounds.  An LED.

[toneman]

Just a note....
No, not *that* note....  
"Sequencers" come in different flavors.
The old (large)Thunderbirds used sequential tail lites.
Most synthesizer sequencers sequence One-lite-at-a-time.
Some are reversable.
(see the SuperSeq by Thomas Henry)\
Remember the Thing "Cylon"---
"By your command".
or "Knight Rider".
Both of these are *back-and-forth* sequencers.
The first/earliest type of sequencer is a "ring counter".
These only count/sequence in one direction.
PAiA's 4710 sequencer is an example of a ring counter.
Your application is actually a third type.
If i remember correctly, the Thunderbird taillights sequenced
"outward", mainly being used for the turn signals.
So, neither a "ring counter" or a "normal" up/down sequencer
would really B applicable.
As for driving hi-pwr lites from low-power electronics---
yes, relays are OK.  In fact, this is how Ford did it!!!
The MOSFET idea link, 2 me, is definitely the way to go.
Again, the lights should sequence from inside to outside.
The lites whould remain lit as they sequence outward.
When all lites are on, lites then all go out and pattern repeats.
email oflist for more help, or PM me first...
AFN
tone

[DouglAss]

GE_WIZ wrote:

Nice try, but you used the term "Light Emitting Diode". If that is the case, the article "a" would be correct because the word "light" begins with a consonant sound. <a light emiting diode> Phonetically, the acronym for that device is "el ee dee" beginning with a soft vowel, hence wanting the article "an".<an LED>  :wink:
[/b]

Here's the weird part, "el ee dee" isn't an acronym, but "led" (pronounced as a word is).  L.E.D. is technically an initialism (with or without the periods), but people have gotten so used to using the term acronym that even dictonaries are starting to list initialism as a second definition for acronym :x
George Carlin has a funny bit on second definitions and misused words
"yeah, there's a reason it is the seond definition.  It isn't as good as the first"



Unfortunately, your UFO example demonstrates the inconsistancies of the English language!!! :oops: "unidentified flying object" demands the article "an" by virtue of the soft vowel "u", whereas "UFO"<yu ef oh> has that pesky "Y" consonent/vowel rule that has no rule! The correct usage is "an unidentified flying object> and <a ufo>.  :roll:



Agreed! I think it's just based on ssound of the phenome, not the letter (sort of like the silent "h" rule)
An hour
A helicopter

not that that makes it any more sensical  :shock:

[nirvanas silence]

I found some 2N3055's and was wondering if I can use them effectively in this circuit with the LM3914 to drive the relay.  If so, how would I do it?

[Ge_Whiz]

<Sigh> It's only I and the Oxford English Dictionary that are wrong, then.

[smoguzbenjamin]

:mrgreen: haha lol.

I go to bilingual (and expensive) classes, some of my classes are in english, and it's quite annoying that the teachers that are supposed to be makin you a native speaker (unless you allready are one like me ) can't speak English themselves :mrgreen: They get so confuzzled all the time it's funny sometimes. Another plus is that because the classes are in 'English' the stuff you cover isn't as hard. Which means easy A's

[nirvanas silence]

<Sigh> It's only I and the Oxford English Dictionary that are wrong, then.

Regardless of what a dictionary says, its a commonsense rule.  How do you pronounce LED?  If its "el ee dee" then using an "a" before it will just go against the rule of using a/an.  Whether its an acronym or abbreviation or anything like that doesn't matter.

[Ge_Whiz]

That's part of the point - unless we have users here who have to read out loud, we're not speaking these postings - we're writing them... Hence my original comments have nothing to do with how the acronyms sound. They are a convention of written English. When you read it out loud, the reader is expected to decode the acronym or abbreviation in full. Led is not a noun, nor is ess ay ee, nor yoo-fo.

Enough. I rest my case.

[niftydog]

I found some 2N3055's and was wondering if I can use them effectively in this circuit with the LM3914 to drive the relay. If so, how would I do it?

Yes you can, but, we can't hold your hand the whole way, it's time to suck it up and possibly blow a few transistors up while you figure it out!

You might not have enough grunt out of the 3914 to directly drive a 3055. You might have to build a darlington....

Wait a sec, what happened to the darlington array chip?

I posted some pictures when I was talking about the PICAXE chips, that will give you some idea of how to go about it.

3914 out to 3055 base, coil from 12V to collector, ground the emitter... possibly some resistors in there someplace...

[niftydog]

by extraordinary coincedence, here's you answer!

http://fclarke.softwareballistics.com/Distortion/Schematic.html

thanks Eric H!