Ronja Twibright Labs

Ronja 10M Metropolis, Tetrapolis, Inferno, Rexlator distance issues

Calculating range from known technical parameters

Recommended combinations

There are 72 combinations how to set up a single Ronja transmitter. Some of them are very efficient, some not so much. Four of them have been selected as recommended. See PostScript or PDF, Fig. 17

Calculating required lens diameter from range

Guess some transmitter and receiver lens diameter and perform range calculation according to the above. Then adjust your guess according to the result.

Nevertheless it's recommended to have the lenses as big as conveniently possible, i. e. the best recommended combination. It is always handy to have extra reliability during fog. However in some situation big optical heads are not welcome, in which a reasonable compromise must be made.

Additional interesting numbers

Lens gain

The lenses are for Ronja like antennae for microwaves (WiFi). Gain in decibels can be assigned to them as well as to the WiFi antennae. Antenna (lens) gain is defined firly simply: it's how many times the density of the energy beam becomes bigger when you start with isotropic radiator and suddenly put the antenna over the radiator.

The gain is dependent also on LED geometry (smaller LED's are sensitive to lens' aberration which blurs them out and lowers the gain) and the wavelength (the glass of lens absorbs different wavelengths differently).

Therefore gains were measured for 3 families: red diodes (HPWT-B family), HSDL4220 infra diode and HSDL4230 infra diode. See PostScript or PDF, Fig. 3,4,5.

Source codes of the calculations

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