Light emiting diode (LED) tube lamp capable of adapting to different driving environments

A light emitting diode (LED) tube lamp, comprising:

• a lamp tube;
• a first pin and a second pin, coupled to the lamp tube, for receiving an external driving signal;
• a first rectifying circuit configured to rectify the external driving signal to produce a rectified signal;
• a filtering circuit coupled to the first rectifying circuit and configured to filter the rectified signal to produce a filtered signal;
• an LED lighting module coupled to the filtering circuit and configured to receive the filtered signal for emitting light;
• and
• a ballast detection circuit coupled to the first pin or the second pin, and coupled to the first rectifying circuit, and comprising a detection circuit and a switching circuit, the switching circuit coupled to a first switching terminal and a second switching terminal, wherein the ballast detection circuit is configured to detect whether the external driving signal comes from a ballast, and is configured to control, based on a result of the detection, current conduction or cutoff of the switching circuit, to determine whether to conduct current by the switching circuit, which current bypasses a circuit path other than the switching circuit;
• wherein when a result of the detection is that the external driving signal is a relatively high frequency AC signal from a ballast, the switching circuit enters a cutoff state allowing the external driving signal to be transmitted through a circuit path other than the switching circuit;
• and when a result of the detection is that the external driving signal is a relatively low frequency or DC signal, the switching circuit conducts current bypassing a circuit path other than the switching circuit.

A light emitting diode (LED) tube lamp, comprising:

• a lamp tube;
• a first pin and a second pin, coupled to the lamp tube, for receiving an external driving signal;
• a first rectifying circuit configured to rectify the external driving signal to produce a rectified signal;
• a filtering circuit coupled to the first rectifying circuit and configured to filter the rectified signal to produce a filtered signal;
• an LED lighting module coupled to the filtering circuit and configured to receive the filtered signal for emitting light;
• a ballast detection circuit coupled to the first pin or the second pin, and coupled to the first rectifying circuit, and comprising a detection circuit and a switching circuit, the switching circuit coupled to a first switching terminal and a second switching terminal, wherein the ballast detection circuit is configured to detect whether the external driving signal comes from a ballast, and is configured to control, based on a result of the detection, current conduction or cutoff of the switching circuit, to determine whether to conduct current by the switching circuit, which current bypasses a circuit path other than the switching circuit;
• and
• a capacitor for generating a detection voltage in response to a signal transmitted through the first switching terminal and the second switching terminal upon the external driving signal being input to the LED tube lamp.

A light emitting diode (LED) tube lamp, comprising:

• a lamp tube;
• a first pin and a second pin, coupled to the lamp tube, for receiving an external driving signal;
• a first rectifying circuit configured to rectify the external driving signal to produce a rectified signal;
• a filtering circuit coupled to the first rectifying circuit and configured to filter the rectified signal to produce a filtered signal;
• an LED lighting module coupled to the filtering circuit and configured to receive the filtered signal for emitting light;
• and
• a ballast detection circuit coupled to the first pin or the second pin, and coupled to the first rectifying circuit, and is configured to detect whether the external driving signal comes from a ballast, wherein the ballast detection circuit comprises a detection circuit and a switching circuit, and the switching circuit is coupled to a first switching terminal and a second switching terminal;
• wherein upon the external driving signal being input to the LED tube lamp:
• when a signal received by the first switching terminal and the second switching terminal is a relatively low frequency AC signal or DC signal, the detection circuit makes the switching circuit conduct current, which current bypasses a circuit path other than the switching circuit;
• and when a signal received by the first switching terminal and the second switching terminal is a relatively high frequency AC signal from a ballast, the switching circuit enters a cutoff state.

A light emitting diode (LED) tube lamp, comprising:

• a lamp tube;
• a first pin and a second pin, coupled to the lamp tube, for receiving an external driving signal;
• a first rectifying circuit configured to rectify the external driving signal to produce a rectified signal;
• a filtering circuit coupled to the first rectifying circuit and configured to filter the rectified signal to produce a filtered signal;
• an LED lighting module coupled to the filtering circuit and configured to receive the filtered signal for emitting light;
• and
• a ballast detection circuit coupled to the first pin or the second pin, and coupled to the first rectifying circuit, and comprising a detection circuit and a switching circuit, the switching circuit coupled to a first switching terminal and a second switching terminal, wherein the ballast detection circuit is configured to detect whether the external driving signal comes from a ballast, and is configured to control, based on a result of the detection, current conduction or cutoff of the switching circuit, to determine whether to conduct current by the switching circuit, which current bypasses a circuit path other than the switching circuit;
• wherein the ballast detection circuit is configured such that, when a result of the detection is that the external driving signal is from a ballast, the switching circuit is configured to enter a cutoff state allowing the external driving signal to be transmitted through a circuit path other than the switching circuit;
• and the circuit path comprises a capacitor coupled between the first switching terminal and the second switching terminal.

A light emitting diode (LED) tube lamp, comprising:

• a lamp tube;
• a first pin and a second pin, coupled to the lamp tube, for receiving an external driving signal;
• a first rectifying circuit configured to rectify the external driving signal to produce a rectified signal;
• a filtering circuit coupled to the first rectifying circuit and configured to filter the rectified signal to produce a filtered signal;
• an LED lighting module coupled to the filtering circuit and configured to receive the filtered signal for emitting light;
• and
• a ballast detection circuit coupled to the first pin or the second pin, and coupled to the first rectifying circuit, wherein the ballast detection circuit comprises a detection circuit and a switching circuit, and the switching circuit is coupled to a first switching terminal and a second switching terminal;
• wherein the ballast detection circuit is configured such that, upon the external driving signal being input to the LED tube lamp, the ballast detection circuit detects whether the external driving signal comes from a ballast, according to a state of a property of the external driving signal, or according to a state of a property of a detection signal transmitted through the first switching terminal and the second switching terminal;
• the property of the external driving signal is the frequency of the external driving signal;
• and the switching circuit is configured to:
• when the external driving signal is a relatively high frequency AC signal, enter a cutoff state, allowing the external driving signal to be transmitted through a circuit path other than the switching circuit;
• and
• when the external driving signal is a relatively low frequency AC signal or DC signal, conduct current, which current bypasses a circuit path other than the switching circuit.