Replacing Old LEDs

[Dwight K. Elvey]

Hi
 You shouldn't plug a LED into a curcuit backwards that
can supply more than about 8 volts someplace. LED's
zener at about 8 to 10 volts and the power
dissipated is much higher when it zeners, even with
a limiting resistor.
 If you get the RS ones that are individually wrapped,
they usually have the polarity marked on the back of
the package. You should be able to check the polarity
with a meter by measuring the voltage from the unit.
Just match the polarities.
Dwight


>From: "Bradley Slavik" <fire at dls.net>
>
>I believe that all these LEDs are on ISA or EISA cards, circa 1987.
>
>Let me be more specific now that I have gone to radio shack.
>
>In 5mm red LEDs they have
>
>12volt, 2.6v, 1.8v
>
>Here are web pages:
>
>http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=276-2
>09
>  
>
>5mm Red LED
>$1.29         Brand: RadioShack
>Catalog #: 276-209         Model: 276-209
>
> 
>Availability    On-line: In-stock    In Store: Check availability
>Phone: In-stock 1-800-THE-SHACK (1-800-843-7422)
>(Pricing and availability may vary outside the contiguous 48 United States.)
>Typical MCD is 1.5. Typical wavelength is 697mm. Size is T-1-3/4 or 5mm. Red
>lens color. Viewing angle is 36°. 10mA (max). Typical Voltage is 2.0, with a
>maximum voltage of 12.0V. Comes as package of 1.
>
>http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=276-0
>41
>
>5mm Red LED
>$1.29         Brand: RadioShack
>Catalog #: 276-041         Model: 276-041
>
> 
>Availability    On-line: In-stock    In Store: Check availability
>Phone: In-stock 1-800-THE-SHACK (1-800-843-7422)
>(Pricing and availability may vary outside the contiguous 48 United States.)
>Typical MCD is 10. Typical wavelength is 700mm. Size is T1 3/4 or 5mm. Red
>lens color. Viewing angle is 30°. Current is 28mA (max). Typical Voltage is
>2.25, with a maximum voltage of 2.6V. Comes as package of 2.
>
>276-330 which is 1.8v does not seem to have web page available.
>
>Should I just put in the 12v one? And turn around if I get it wrong? or
>use jumpers to test it before soldering?
>
>Bradley
>
>
>