Patent ID: 9554429
Date: 2017-01-24
CPC Classifications: B60Q,H05B

Claim:
1. A lighting circuit, in particular for a motor vehicle light, comprising: at least one light source defined by a first voltage selection and susceptible to being driven by a first driving current; a first selection circuit to identify said first voltage selection; at least one light source defined by a second voltage selection and susceptible to being driven by a second driving current; a second selection circuit to identify said second voltage selection; wherein each of said first and second selection circuit includes at least one selection circuit element defined by a selection electric quantity having one of a plurality of predefined levels of electric quantity to which the same number of voltage selection levels of the light sources correspond; an electronic control unit configured to detect said first and second voltage selection of the light source by said first and second selection circuit, and to regulate the driving current absorbed by the light source defined by the lower voltage selection, so that said driving current follows with a constant ratio the trend of the driving current absorbed by the light source defined by the higher voltage selection, the latter being taken as reference; at least a first electronic lighting circuit board including at least said light source defined by the first voltage selection and said first selection circuit; at least a second electronic lighting circuit board including at least said light source defined by the second voltage selection and said second selection circuit; wherein the electronic control unit includes: a current driver for each electronic lighting circuit board, said current driver being suitable for imposing a driving current of the respective light source; a comparison circuit including a circuit suitable for comparing said selection electrical quantities, or electrical quantities derivable from said selection electrical quantities, so as to identify, on the basis of such comparison, the lighting circuit board having the at least one light source with the higher voltage selected; a detection circuit for each of said electronic lighting circuit boards, wherein the detection circuit includes a circuit suitable for detecting a driving electric quantity of the light sources when powered with a power supply voltage; and a regulation circuit including, for each of the electronic lighting circuit boards, a circuit regulator suitable for controlling the respective current driver in such a way that the driving current of one lighting circuit board follows the driving current of the other lighting circuit board with a constant ratio, and wherein said comparator circuit is connected to said current driver and to said circuit regulator in such a way that the lighting circuit with the higher voltage selection is driven by the comparator circuit with a reference driving current, and the driving current of the other lighting circuit board is regulated by the respective circuit regulator so as to follow said reference current with a constant ratio.