COB_dimming.mspct {photobiologyLEDs}

Constant-current dimming of LEDs

Description

A collection of emission spectra of a light-emitting-diode driven at different constant current.

Usage

COB_dimming.mspct

COB_dimming.tb

Format

A "source_mspct" object containing 8 "source_spct" objects.

In each of the member spectra, the variables are as follows:

• w.length (nm)

• s.e.irrad (W m-2 nm-1)

An object of class tbl_df (inherits from tbl, data.frame) with 8 rows and 6 columns.

Details

The "COB_dimming.mspct" object contains "source_spct" objects with spectral irradiance data with the same Optisolis COB LED from Nichia driven at different values of constant current. Distance from LED to cosine diffuser was 159 mm; a reflector was attached to the LED to make the light beam narrower. Spectra are not normalized. The position for the LED with respect to the entrace optics did not vary among measurements.

The COB LED used is the chip-on-board (COB) Optisolis type NFCWL036B-V3-Rfcb0 from Nichia with CRI > 95. Nominal electrical power of 10.3 W at nominal current of 270 mA. So, two spectra are for the COB over-driven, which is possible with enough cooling, but not recommended.

The spectral data are not expressed at constant wavelength intervals. Not only the intervals vary in the raw data from the array spectrometer, but in addition function thin_wl has been applied to reduce the storage space needed. In brief the wavelength interval has been increased as much as possible in those regions of the spectrum that lack detailed features (such as linear slopes and wavelength regions with zero light emission).

Note

Please see the metadata in each spectrum. These metadata are stored as attributes of the individual source_spct objects and can accessed with functions comment, getWhatMeasured, getWhenMeasured, getHowMeasured, getInstrDesc and getInstrSettings. See also the comment attribute of the COB_dimming.mspct object.

References

https://www.ledil.com/ https://www.nichia.co.jp/en/

Examples

library(photobiology)

names(COB_dimming.mspct)

# photon irradiance in umol m-2 s-1, and relative to maximum
q_irrad(COB_dimming.mspct, scale.factor = 1e6)

# precomputed values and measured supply current
COB_dimming.tb