Power supply for supplying power to a lamp

A power supply, having an alternating current (AC) output for supplying power to a lamp, the power supply comprising:

• an energy transfer element, comprising an energy transfer input end and an energy transfer output end coupled to the output of the power supply;
• a power control circuit comprising a energy control circuit coupled to the energy transfer element;
• a dimming circuit comprising a switching element and a dimming control circuit, in which the switching element is coupled to the power control circuit, the dimming control circuit is coupled to the switching element and receives a dimming signal, and switches the switching element in response to the dimming signal, the power control circuit increases a frequency of the AC output to a frequency range in response to switching of the switching element, and turns off the power supply when the frequency exceeds a pre-determined value;
• a photo coupler coupled to the switching element and the power control circuit, in which the photo coupler generates a coupling signal in response to turn-on mode of the switching element, the power control circuit increases the frequency of the AC output to the frequency range in response to the coupling signal, and turns off the power supply when the frequency exceeds the pre-determined value;
• and
• an over-voltage detect circuit coupled to the output of the power supply and the photo coupler, driving the photo coupler to generate the coupling signal in response to the output of the power supply.

A power supply, having an alternating current (AC) output for supplying power to a lamp, the power supply comprising:

• an energy transfer element, comprising an energy transfer input end and an energy transfer output end coupled to the output of the power supply;
• a power control circuit comprising a energy control circuit coupled to the energy transfer element;
• a dimming circuit comprising a switching element and a dimming control circuit, in which the switching element is coupled to the power control circuit, the dimming control circuit is coupled to the switching element and receives a dimming signal, and switches the switching element in response to the dimming signal, the power control circuit increases a frequency of the AC output to a frequency range in response to switching of the switching element, and turns off the power supply when the frequency exceeds a pre-determined value;
• and
• a high high-frequency current detection circuit comprising:
• a first capacitive element, coupled to the AC output of the power supply, being adapted to receive a current of the AC output;
• a resistor connected to the first capacitive element in series;
• and
• a second capacitive element connected to the resistor in parallel;
• wherein, in response to a frequency variation of the current, the first capacitive element and the second capacitive element are adapted to generate a high-frequency current detecting signal in a junction of the resistor and the first capacitive element, and the power control circuit is configured to turn off the power supply when the frequency exceeds a high-frequency reference.

A power supply, having an alternating current (AC) output for supplying power to a lamp, the power supply comprising:

• an energy transfer element, comprising an energy transfer input end and an energy transfer output end coupled to the output of the power supply;
• a power control circuit comprising a energy control circuit coupled to the energy transfer element;
• a dimming circuit comprising a switching element and a dimming control circuit, in which the switching element is coupled to the power control circuit, the dimming control circuit is coupled to the switching element and receives a dimming signal, and switches the switching element in response to the dimming signal, the power control circuit increases a frequency of the AC output to a frequency range in response to switching of the switching element, and turns off the power supply when the frequency exceeds a pre-determined value;
• and
• a current adjusting circuit comprising:
• a temperature sensing module, being configured to sense an environment temperature and to generate a sensing voltage signal in response to the environment temperature;
• and
• a feedback circuit, coupled to the temperature sensing module, being configured to generate a feedback signal in response to the sensing voltage signal, the feedback signal being adapted to modulate the switching element by a switching frequency thereof to change the frequency of the AC output.