H-bridge dimming and color temperature adjusting two-line output circuit and LED dimming power supply
The present invention discloses an H-bridge dimming and color temperature adjusting two-line output circuit and an LED dimming power supply. The H-bridge dimming and color temperature adjusting two-line output circuit includes a first signal generator U 1 , a second signal generator U 2 , a first switch transistor Q 1 , a second switch transistor Q 2 , a third switch transistor Q 3 , and a fourth switch transistor Q 4 . Through the above structure, it is possible to achieve two-line dimming and color temperature adjustment without distinguishing between positive and negative electrodes. The H-bridge dimming and color temperature adjusting two-line output circuit has the advantages of simple circuit connection, fewer devices, low cost, stable performance, and smooth dimming.
1 . An H-bridge dimming and color temperature adjusting two-line output circuit, comprising a first signal generator U 1 , a second signal generator U 2 , a first switch transistor Q 1 , a second switch transistor Q 2 , a third switch transistor Q 3 , and a fourth switch transistor Q 4 , wherein
the first signal generator U 1 is connected to a first PWM signal, the second signal generator U 2 is connected to a second PWM signal, and duty cycles of the first PWM signal and the second PWM signal are complementary;
a control terminal of the first switch transistor Q 1 and a control terminal of the third switch transistor Q 3 are connected to the first signal generator U 1 , and a control terminal of the second switch transistor Q 2 and a control terminal of the fourth switch transistor Q 4 are connected to the second signal generator U 2 ;
an input terminal of the first switch transistor Q 1 and an input terminal of the second switch transistor Q 2 are connected to a V+ terminal;
an output terminal of the first switch transistor Q 1 is connected to an input terminal of the third switch transistor Q 3 , a positive electrode of a cold light lamp group ( 10 ), and a negative electrode of a warm light lamp group ( 20 ), respectively, and an output terminal of the second switch transistor Q 2 is connected to an input terminal of the fourth switch transistor Q 4 , a negative electrode of the cold light lamp group ( 10 ), and a positive electrode of the warm light lamp group ( 20 ), respectively; and
an output terminal of the third switch transistor Q 3 and an output terminal of the fourth switch transistor Q 4 are grounded.
2 . The H-bridge dimming and color temperature adjusting two-line output circuit according to claim 1 , further comprising current limiting resistors R 1 in serial connection to the output terminal of the third switch transistor Q 3 , the output terminal of the fourth switch transistor Q 4 and grounding terminals.
3 . The H-bridge dimming and color temperature adjusting two-line output circuit according to claim 1 , wherein the first switch transistor Q 1 , the second switch transistor Q 2 , the third switch transistor Q 3 and the fourth switch transistor Q 4 are MOS transistors.
4 . An LED dimming power supply, comprising an EMI filtering module ( 30 ), an AC-DC module ( 40 ), and the H-bridge dimming and color temperature adjusting two-line output circuit according to claim 1 , wherein the EMI filtering module ( 30 ) is connected between an external power supply and an input terminal of the AC-DC module ( 40 ), the AC-DC module ( 40 ) outputs the V+ terminal and a VCC terminal, the first signal generator U 1 and/or the second signal generator U 2 are/is connected to the VCC terminal, and the input terminal of the first switch transistor Q 1 and the input terminal of the second switch transistor Q 2 are connected to the V+ terminal.