LED Help

[dougdagrump]

Need some help in finding the correct LED. That is me when it comes to most anything electric.

Two or three months back I picked up a solar powered lighthouse for the garden train at WallyWorld on a $10 blowout, now I know why they were being blownout. As a result of poor build quality there appears to have been a good deal of water intrusion from the sprinklers. It is my assumption that this caused a lot of the visable corrosion on the leads at the base of the LED resulting in failure, broken lead at the base of the LED. The small circuit board shows no signs of any corrosion or damage. 

I am looking to replace the LED but have NO idea as to what the proper size would be. As stated before this is powered by a single AA Ni-MH which is recharged by a small solar panel on top.

Any info greatly appreciated, thanks.

Doug 

 

[csxt30]

Hoping this site may help, Doug.  

http://www.scottsodds-n-ends.com/products.htm

Thanks, John

[eZAK]

Any LED rated for 1.5v will work. Try LHS, Radio Shack, or Fry's Elec.

[jefelectric]

Doug, eZAK is correct, but you will not get the same light output from all LEDs.  Just try trial and error.  Note that they are polarity sensitive.  See this site for the basics.

http://www.kpsec.freeuk.com/components/led.htm

Hope this helps.

[wrmcclellan]

Doug,

Assuming you are talking about a white LED?

[dougdagrump]

Doug,

Assuming you are talking about a white LED?

The current one was yellow but not very bright, kinda like moi, so I was considering changing to white.  

[wrmcclellan]

Doug,

Your current circuit may not power a white LED which has a higher voltage drop (ie requires a higher voltage to run) than a yellow LED.

White LEDS require 3.2 to 4 volts to operate.

Regular bright LEDS (red, yellow, green) require about 1.5 - 2 volts to operate. You will need to replace it with another yellow LED.

Another couple of questions before we go too far.

1. Is the plastic lens on the LED yellow or clear (If clear you only see yellow when it is lit - clear LED lenses can mean this is a super bright LED).

2. What diameter is the LED? Standard sizes for round lenses are 3 mm, 5 mm, & 10 mm.

3. At this time do not remove the current LED. The plastic lens may be marked so we know the polarity when replacing it.

If you look at the LED from its end - if it is a common 5 mm LED, you should see that on one side, the plastic lens has a flat spot on it. This denotes the cathode (important for polarity). If you can see this, look and see if the circuit board is similarly marked. If not, mark the circuit board so you know which side the flat spot is on.

Otherwise, look and see if the circuit board is marked with a diode symbol where the LED is mounted. The symbol looks like an arrowhead with a line on the tip  (sorta like this -->l--).

Unfortunately some cheap 3 mm LEDS may not have the flat spot (I have several in my parts box).

It is helpful to know which way to install the new LED before you remove the old LED.

 

[dougdagrump]

Doug,

Your current circuit may not power a white LED which has a higher voltage drop (ie requires a higher voltage to run) than a yellow LED.

White LEDS require 3.2 to 4 volts to operate.

Regular bright LEDS (red, yellow, green) require about 1.5 - 2 volts to operate. You will need to replace it with another yellow LED.

Another couple of questions before we go too far.

1. Is the plastic lens on the LED yellow or clear (If clear you only see yellow when it is lit - clear LED lenses can mean this is a super bright LED).

2. What diameter is the LED? Standard sizes for round lenses are 3 mm, 5 mm, & 10 mm.

3. At this time do not remove the current LED. The plastic lens may be marked so we know the polarity when replacing it.

If you look at the LED from its end - if it is a common 5 mm LED, you should see that on one side, the plastic lens has a flat spot on it. This denotes the cathode (important for polarity). If you can see this, look and see if the circuit board is similarly marked. If not, mark the circuit board so you know which side the flat spot is on.

Otherwise, look and see if the circuit board is marked with a diode symbol where the LED is mounted. The symbol looks like an arrowhead with a line on the tip  (sorta like this -->l--).

Unfortunately some cheap 3 mm LEDS may not have the flat spot (I have several in my parts box).

It is helpful to know which way to install the new LED before you remove the old LED.

 

Roy, My guess is that it is a 5mm super brite. It is clear with the orientation flat on the side as well as the board being labeled. Went by my local RadioShack and Frye's as well, but alas neither had anything within the required power range. Thought I was going to require the services of Doug M's eye doctor after reading all the labels at Frye's.

 

[dbaker48]

Okay...  What am I missing here?

Are we talking about a $10 light?  Now I know things can get slow in Insane Diego, but Doug???

An led going cost .15 - .85 ?  Shipping probably $5 or $6 or will call...

Gas at $3 /gallon  probably 20 miles + close to shipping cost ?

Now labor and time.... Well you have plenty of time non issue, labor? unlimited sources.

I guess it does make sense.   

[wrmcclellan]

Don,

We're men - it's the principle involved and eons of genetic evolution/programming.

Don't fight it - you'll eat grits and talk funny...

Doug,

This item from RS should work:

Catalog #: 276-351

http://www.radioshack.com/product/index.jsp?productId=2103803&cp=2032058.2032233.2032298&parentPage=family

 

[dougdagrump]

Roy, Much thanks, it's working like a champ.

Don, It was a $1.50 and only a few blocks away, plus gas in Escondido is only $2.80/gal for regular.  It still beats 30 or 40 bucks for a new one and I'm to **** old to be rearranging that end of the garden layout. At least with the smaller gauges you normally get to work in a controlled environment ( air conditioning ). 

[dbaker48]

Doug --- And here I  just thought you were trying to save a $1, I thought you said the lamp was $10, because we do see some at the computer fair for that price.  Stake in the ground solar.  I would have sent you one.

Anyway I'm waiting for you to get that done so I can come down and get lessons.  Remember to keep it secure.

 On you $40 train and $1000 layout.  I'm doing just about the same. 

[dougdagrump]

Don, Sssshhhh ! My wife would probably raise all kinds of **** if she knew what we have spent after her "Great Buy". Although when little Mr. K sits with Grampa and watches the trains it would be more than worth it to catch **** .