Yet another electronics question updated 9/4/8

[sycor]

New question:
Okay, so if I'm using an illuminated rocker switch like this one:

How do I wire it into the circuit? I know it has 3 connector thingies but I'm not sure which ones to use and the one I have didn't come with any diagram or anything. My google-fu is very bad this morning and I couldn't find anything.


You guys seem to have a grasp on this LED thing. Another question for you. If I use an AC-DC converter rated at 12VDC and 500 mA and say I want to use 1.5V 15mA LEDs (we'll say 7 LEDs with a 100 ohm resistor), would the 500 mA of the converter be a problem? (I'm sure I didn't ask that question right so feel free to say, "huh?")

 

[jackdoud]

Re: Yet another electronics question (blinking lights)

You'll probably need a couple 555 timers. Off hand I'd say one for the "steady on" time and one occilator that cuts in for the blinking.

 

[sycor]

Re: Yet another electronics question (blinking lights)

Do you have english translation for what you just said?

 

[ItsThatGuy]

Re: Yet another electronics question (blinking lights)

It's probably easier to just pay some guy to flip the switch on and off every-so-often to give it that blinking effect.

 

[Darkside]

Re: Yet another electronics question (blinking lights)

the easy way would be an ic 4017 this is a normal counter.
with an 555 for the frequency

it has 10 outputs. the right side in the pic is useless for you.
you just need the 555 and the ic side. with P1 you can adjsut the speed.

now with the set frequency, Q is set on from Q0 to Q9
just connect an led on this and it goes on and of when the Q* is on.
connect the same led on more Q`s so it will go on when this Q`s are set.
(so for Q1 and maybe Q3)
so a randomly looking blinking should be easy.


hopefully its clear. so please ask.

edit this is what you need http://www.allaboutcircuits.com/vol_6/chpt_7/6.html
just replace the led bar and use leds as said above
if there is only one led typ and one led connected one resistor should be enough.
so you dont need 10 of them

 

[sycor]

Re: Yet another electronics question (blinking lights)

I can kind of understand what you are saying but I have no idea to make it. :unsure I'm somewhere around beginner level with this kind of thing. It might just be easier to keep the light steady.

 

[Coz]

Re: Yet another electronics question (blinking lights)

Might be a little too fast for your needs (I'm guessing it to resemble a bad neon light effect?), but you might be able to use a battery powered flickering tea-light candle. The ones I have run on 3 regular watch batteries.

They have one LED, and it flickers to its own beat, not just on/off (there's an Instructable that explains that a musical circuit is used, with the LED in place of the speaker.

If you could rig that up to a couple of LEDs, they'd flicker at the same rate.

C.

 

[sycor]

Re: Yet another electronics question (blinking lights)

That might could work. Will just have to get the board out of the "candle" without damaging it.

 

[Great_Bizarro]

Re: Yet another electronics question (blinking lights)

You used to be able to purchase a premade one that was used by model railroaders to model the light from a campfire. Search on that as it may give you the easiest way to do it. There are also some items out around Halloween that do much the same thing.

 

[Rhett J Martin]

Re: Yet another electronics question (blinking lights)

There's also some welding light circuits that are made that look great, and are very bright.

 

[Coz]

Re: Yet another electronics question (blinking lights)

Addendum to my previous post -

Just opened one of the flickering tea-lights, and all there is inside is the LED! No circuit or anything. Battery, switch & LED only. Must be something in the LED (random / semi-random flicker).

Some may well be different tho!

Might there also be a dolls house fireplace light circuit?

C.

 

[tim]

Re: Yet another electronics question (blinking lights)

^ There should be a small IC inside the LED casing. You might be able to see it as a small black speck about 1 mm long.

You used to be able to get LEDs like this at Radio Shack, but all they did was blink at a steady rate, much like what one would get with an LM3909-based LED flasher circuit.

 

[sycor]

Re: Yet another electronics question (blinking lights)

Anyone want to build me a circuit? $10?

 

[tim]

Re: Yet another electronics question (blinking lights)

Anyone want to build me a circuit? $10?

It's more fun if you do it yourself. Plus, the parts cost alone would exceed $10.

 

[sycor]

Re: Yet another electronics question (blinking lights)

updated question:

You guys seem to have a grasp on this LED thing. Another question for you. If I use an AC-DC converter rated at 12VDC and 500 mA and say I want to use 1.5V 15mA LEDs (we'll say 7 LEDs with a 100 ohm resistor), would the 500 mA of the converter be a problem? (I'm sure I didn't ask that question right so feel free to say, "huh?")

 

[jackdoud]

Re: Yet another electronics question updated 9/2/8

The transformer is supplying 500ma so if your LEDs require 15ma then you can techinically power 33.3 of them at full power. Granted the resistor and wires take up some power and 15ma is only the nominal rating. As long as you stay somewhere under 450ma draw (30 LEDs) you shouldn't have any problems. :thumbsup

 

[RGPFX]

Re: Yet another electronics question updated 9/2/8

New question:
You guys seem to have a grasp on this LED thing. Another question for you. If I use an AC-DC converter rated at 12VDC and 500 mA and say I want to use 1.5V 15mA LEDs (we'll say 7 LEDs with a 100 ohm resistor), would the 500 mA of the converter be a problem? (I'm sure I didn't ask that question right so feel free to say, "huh?")

Your question is both well stated and understandably a source of confusion for non-electrical hobbyists. The 500 ma rating is the maximum the unit can safely supply. It can provide any amount under that with no problem. It will NOT attempt to drive a half amp of current through your delicate LED's.
You will simply calculate your resistor array just as if you were using any 12V source supply.

Good luck.

As usual, should you be caught or worse, the RPF will disavow any knowledge of your actions.

RGP

 

[exoray]

Re: Yet another electronics question updated 9/2/8

Anyone want to build me a circuit? $10?

Well not for $10 but if you are desperate and really don't want to do it yes, I could put something together for you...

 

[Mr.Engineer]

Re: Yet another electronics question updated 9/2/8

You might want to go here: http://led.linear1.org/led.wiz

Just put the source voltage as 12v
Led forward voltage as (Well, 1.8 to 2.0volts)
Led forward current is 15mA (I prefer 20mA for RED)
And the number of LEDs

The you'd get a few circuit variations.

As the guys mentioned, the 500mA in the power adaptor is the maximum limit (or when it starts to get diturbingly hot) so, the above circuit will still make the adaptor function well within its operational parameters.

 

[sycor]

Re: Yet another electronics question updated 9/2/8

So, if I wanted to actually use more LEDs I could just use a 12VDC 1000 mA converter and still just calculate everything based on the 12VC when figuring out my resistor. Thanks guys!