led

[Zman]

Hey there

when placed in the sun, a small led gives off a reading on my voltmeter,
goes up and down. The only thing is, how do i know what reverse
current/voltage im going to get just by looking at the information? is there
a formula to use and does mCd make a diff in voltage or current when giving
power out?

the specs are

15VDC 5mm LED
(all typical values)
luminous intensity 120
Peak emission wavelength 573
spectral half width 15
flash rate (freq) 2.4
operating voltage 5
forward voltage 5
reverse voltage .04


thank you

 

[Eddie]

strange led spec, but yes, not many people know that a led will generate a
small voltage and bugger-all current when exposed to light


"Zman" <mr@mr.com> wrote in message
news:41c7d6f8$1@duster.adelaide.on.net...

Hey there

when placed in the sun, a small led gives off a reading on my voltmeter,
goes up and down. The only thing is, how do i know what reverse
current/voltage im going to get just by looking at the information? is
there
a formula to use and does mCd make a diff in voltage or current when
giving
power out?

the specs are

15VDC 5mm LED
(all typical values)
luminous intensity 120
Peak emission wavelength 573
spectral half width 15
flash rate (freq) 2.4
operating voltage 5
forward voltage 5
reverse voltage .04


thank you

 

[Rheilly Phoull]

"Zman" <mr@mr.com> wrote in message
news:41c7d6f8$1@duster.adelaide.on.net...

Hey there

when placed in the sun, a small led gives off a reading on my voltmeter,
goes up and down. The only thing is, how do i know what reverse
current/voltage im going to get just by looking at the information? is
there
a formula to use and does mCd make a diff in voltage or current when
giving
power out?

the specs are

15VDC 5mm LED
(all typical values)
luminous intensity 120
Peak emission wavelength 573
spectral half width 15
flash rate (freq) 2.4
operating voltage 5
forward voltage 5
reverse voltage .04


thank you

Didn't you like the fairly comprehensive replies before ??
Why use a flashing LED for this purpose ??
Particularly against expert advice ??

--
Regards ..... Rheilly Phoull

 

[MC]

Zman wrote:

Hey there

when placed in the sun, a small led gives off a reading on my voltmeter,
goes up and down. The only thing is, how do i know what reverse
current/voltage im going to get just by looking at the information? is there
a formula to use and does mCd make a diff in voltage or current when giving
power out?

Actually *all* semiconductors will produce some voltage and current
if given enough radiation.
One reason why most semiconductors are enclosed in optically-opaque
packaging is to try and reduce optical side-effects.

Unless the device has been specifically designed for power generation
(ie. a solar cell), then you'll find that the enery-conversion
efficiency is rather low and the output will depend a lot on what the
semiconductor material actually is.