Driving power supply for lamps

Abstract

The invention discloses a driving power supply for lamps. The driving power supply is free of an electrolytic capacitor. Various circuit topology power supplies are sine pulsating DC voltage. The driving power supply comprises a high-frequency conversion circuit, which is a self-excited oscillator of which a triode works in a soft-switching state; and power frequency AC voltage is converted into amplitude-modulated high-frequency voltage of power frequency sine pulsating DC voltage to provide an LED drive circuit with a working power supply which is isolated with commercial power. The LED drive circuit has three control modes of analogue voltage regulation, load parallel shunting and a buck (Buck) circuit; a control circuit of the LED drive circuit does not need to be additionally provided with an independent DC working power supply; and the limit on the number of LED load lamps and voltage is avoided. The high-frequency conversion circuit can be a gas discharge lamp driving power supply, provides starting high voltage required for lamp activation and has power tube overvoltage, under-actuation and lamp ageing protection functions.

Description

Technical field [0001] The invention relates to a driving power supply for an LED and a gas discharge lamp, which comprises; [0002] 1: High frequency conversion circuit 2: LED drive circuit Background technique [0003] 1: The disadvantages of using electrolytic capacitors for the driving power supply of lamps; [0004] 1: The lamp drive power supply using commercial power, because the power frequency rectification filter electrolytic capacitor charging current conduction angle is less than 180 degrees, the power factor is reduced, and high-order harmonics are generated. [0005] The national standard and the International Electrotechnical Commission (IEC) both stipulate clear indicators for power factor, and the American "Energy Star" certification standard requires; the power factor of residential SSL lamps is greater than 0.7 (5W) and commercial SSL lamps (including LED street lamps) are greater than 0.9. [0006] 2: The life of the electrolytic capacitor will determi...

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Problems solved by technology

[0006] 2: The life of the electrolytic capacitor will determine the life of the whole lamp. For lamps with built-in drive circuits, due to the airtight and high-temperature working conditions, the life of the electrolytic capacitor will be far less than the expected life of 50,000 hours of LED lamp beads, and the lamps will lose the advantage of using LEDs.

[0007] 3: Active power factor correction technology is used, the circuit is complicated, the cost increases, and the working condition of the filter electrolytic capacitor deteriorates due to the increase of the working frequency, which is not suitable for the lighting market with huge demand, especially for low-power lamps

[0010] Two: the lack of high-frequency conversion circuit;

[0028] 1: There are many types of DC constant current LED lamp drive power supply control chips, all chips must be configured independently and work in a limited DC low voltage state, and the power supply voltage of different chips is different, and the power supply of the driver control circuit cannot be universal and standardized

[0029] If the built-in high voltage constant current source is used for power supply, the chip will heat up due to the increase of power consumption

[0030] 2: Temperature detection is only used for over-temperature shutdown of the chip itself, without LED temperature rise control, and LED temperature rise does determine its service life

[0035] (2): As shown in the start-up sequence diagram (3-88) on page 122 of "Document 3", the chip power supply V CC It needs to be restarted after each power frequency crosses zero, which complicates the control mode

[0041] (2): The chip control is too complicated, the segmented light strings are driven in time-sharing, and the utilization rate of the lamp beads is low

[0042] (3): When the input voltage changes by more than 10%, some lamp beads will become dark or no current will flow.

[0050] (2): The voltage of the LED current sampling resistor has provided the control parameters. For the LED current whose envelope is a sinusoidal pulsation of power frequency, within the limited fluctuation range of the input voltage, controlling the peak current means controlling the average value of the DC current. The chip The reference voltage is generated by calculation, which is used to control the LED current envelope to follow the sinusoidal pulse of the power frequency, and the control mode is too complicated

[0051] (3): The envelope of the LED current is a power frequency sine wave. Because the peak ratio is relatively large, the lamp will appear 100 cycles of visual flickering

[0053] (5): Only detect the temperature rise caused by the chip's own power consumption, without the LED temperature rise control function that determines the life of the lamp

The withstand voltage of the device is lower than 50V, the current is lower than 30mA, the LED current value cannot be adjusted, and there is no temperature control function

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