LED Help

[Stampedemag]

Anyone out there a guru in wiring? I am working on a prop that will have 9 led's that light up like 1 then 3 then 5, 7, 9.

I want to incorporate a ring like device to turn up the led's almost like a dimmer switch. I know basic wiring but how would I go about making something like that?

 

[Stampedemag]

No one can help? I know that someone out there must know something. Come on guys.

What I need is something that will light up led's in a sequential pattern like the MR Sabers do. (No, it is not for a saber)

 

[hyperdyne]

You can buy a saber driver that will do this, if you just want the LEDs to ignite and retract.

If you need something different, you might have to get something custom made. You can do this with discrete logic, a couple shift registers and a clock circuit.

 

[motman241]

http://www.uoguelph.ca/~antoon/gadgets/bfflash2.htm

That was just the first return from Googling 'sequential LED circuit'.

 

[ATL Kenobi]

This circuit, I believe, will do what you're asking:
LM3914 data sheet
The 0-5 volt source can be a simple potentiometer (10k ohm) across 5 volts, with the wiper connected to pin 5.

ATL

 

[Stampedemag]

Those look great. Somewhat complicated but great. I haven't delved into making my own circuit boards but how hard could it be right? :eek

I think those will make them light up all at the same time right? I need them to go from 1,3,5,7,9 to make matters worse and harder I need them to light up from the center to the edges starting with the center LED then until all are lit.

It looks like I will be spending some money at Radio Shack soon. Any other tips and pointers would be greatly appreciated. :thumbsup

 

[motman241]

<div class='quotetop'>QUOTE(Stampedemag @ Jan 15 2007, 08:00 PM) [snapback]1397797[/snapback]</div>

I think those will make them light up all at the same time right? [/b]

You wanted a sequential circuit. They will light up in sequence - LED #1, then LED #2, then LED #3, etc.

They don't have to go from left to right, either. You can put them right to left. Or mix and match for a "random" pattern. Whatever you want to do.


Oh, and just so everyone knows - the Radio Shacks in a mall no longer sell parts. You have to go to the non-mall Shacks. Dumb, huh?

 

[Pilot]

<div class='quotetop'>QUOTE(Stampedemag @ Jan 15 2007, 12:00 PM) [snapback]1397797[/snapback]</div>

Any other tips and pointers would be greatly appreciated. :thumbsup
[/b]

Tip: Try not to buy discrete components at Radio Shack in any quantity. Their selection is very limited and quite overpriced.

If you need to get some stuff there to tinker with initially, I completely understand...but when you've got a solid idea of where you're going and what you'll need to to make a finished product, direct thyself to an online supplier like BG Micro and save yourself some money.

 

[ATL Kenobi]

The circuit that motman241 pointed out is a cool circuit and does sequence LEDs but only one will be on at a time. LED 1 will come on first, then LED 2 comes on as LED 1 goes off and so forth up to LED 10 which is followed by LED 9 and then it sequences back down to LED 1. Then this whole cycle repeats.

Now if I understand correctly, I believe you're looking for a circuit like this:

OOPs :$ -Just noticed the D8 between D5 and D9 should have been labeled D7- but you get the idea.

As the 10k potentiometer (adjuster knob) is turned, LED D1 comes on first by itself. As the knob is turned more, LED D1 stays on and D2 and D3 illuminate on either side of D1, for a total of 3 LEDs. Turning the knob some more and D4 and D5 illuminate for a total of 5 LEDs, then D6 and D7 (7 LEDs on), and then D8 and D9, for a total of 9 LEDs on. Reversing the knob, and they will turn back off in reverse order.

I engineered this and drew it up in AutoCad rather quickly, but I think the resistor values are correct. LMK. I wouldn't bother with a printed circuit board unless you plan to make a lot of them. I'd just wire right to a dual-in-line package IC on a small bread board. The circuit values are seleted for 20mA LED drive, so since D1 is by itself it needs to be a 20mA device, and the paired LEDs need to be 10mA.

ATL

 

[motman241]

<div class='quotetop'>QUOTE(Pilot @ Jan 16 2007, 02:59 AM) [snapback]1398105[/snapback]</div>

Tip: Try not to buy discrete components at Radio Shack in any quantity. Their selection is very limited and quite overpriced.
[/b]

I agree. I would hope everyone would Email Radio Shack, and let them know that we are buying parts elsewhere.

 

[Stampedemag]

Thank you thank you thank you.

This will help out a bunch. I hope to make something up in the next couple of days. If it works I may ask some help on making it more professional looking. Wish me luck.

Is there a way to have an override momentary switch to turn them all on and still keep the potentiometer ?

 

[neophyl]

If you connect pin 5 to the 30k resistor via a switch (thereby bypassing the variable resistor) it will in effect be the same as turning the dial all the way up. That should light them all at the push of a button.

 

[Stampedemag]

<div class='quotetop'>QUOTE(neophyl @ Jan 16 2007, 07:22 AM) [snapback]1398327[/snapback]</div>

If you connect pin 5 to the 30k resistor via a switch (thereby bypassing the variable resistor) it will in effect be the same as turning the dial all the way up. That should light them all at the push of a button.
[/b]

So I would be able to have both switchs work then? Just wire both switches inline? When either is activated it would work right?

 

[Corellianexports]

Fiberoptics has a "cylon" kit that could light up your LEDs in sequencial order:

http://www.fiberopticproducts.com/danise/c...;category=Cylon

Click on home and there's also a "drag race" kit that has 2 sets of LEDs. That might work even better.

Good luck.

 

[SurferGeek]

<div class='quotetop'>QUOTE(Stampedemag @ Jan 16 2007, 07:29 AM) [snapback]1398330[/snapback]</div>

<div class='quotetop'>QUOTE(neophyl @ Jan 16 2007, 07:22 AM) [snapback]1398327[/snapback]

If you connect pin 5 to the 30k resistor via a switch (thereby bypassing the variable resistor) it will in effect be the same as turning the dial all the way up. That should light them all at the push of a button.
[/b]

So I would be able to have both switchs work then? Just wire both switches inline? When either is activated it would work right?
[/b][/quote]


Nice avatar. :rolleyes

 

[Stampedemag]

<div class='quotetop'>QUOTE(SurferGeek @ Jan 17 2007, 11:09 PM) [snapback]1399594[/snapback]</div>

<div class='quotetop'>QUOTE(Stampedemag @ Jan 16 2007, 07:29 AM) [snapback]1398330[/snapback]

<div class='quotetop'>QUOTE(neophyl @ Jan 16 2007, 07:22 AM) [snapback]1398327[/snapback]

If you connect pin 5 to the 30k resistor via a switch (thereby bypassing the variable resistor) it will in effect be the same as turning the dial all the way up. That should light them all at the push of a button.
[/b]

So I would be able to have both switchs work then? Just wire both switches inline? When either is activated it would work right?
[/b][/quote]


Nice avatar. :rolleyes
[/b][/quote]


Well you did tell me to change it. I haven't had the time to get a new one done up in PS. All of mine are big.

 

[David Moeller]

IF you want to order online, www.digikey.com is the place to go. The LM3914 is a low cost chip, and for the price of shipping you might want to consider buying a tube (24?) I have done that in the past, and I never run out of parts.

FYI- the LM3914, LM3915, LM3916 are all in the same family so you might want to see if one of those would be better suited for you.

If you are going to use any high power LED, you might want to consider using some switching transistors (2N2222 will do the trick.)

Dave