Timer based protection circuit and lighting device

A lighting device, comprising a load and a timer based protection circuit, wherein the load comprises a light-emitting element, and timer based protection circuit is configured to:

• acquire a working current or an output voltage of a protected object;
• and
• compare a voltage value converted from a current value of the working current or a voltage value of the acquired output voltage with a predetermined threshold, wherein:
• when the voltage value converted from the current value of the working current or the voltage value of the acquired output voltage is greater than or equal to the predetermined threshold, the protection circuit resets the timer to cause the timer to output a low voltage level, and
• when the voltage value converted from the current value of the working current or the voltage value of the acquired output voltage is less than the predetermined threshold, the timer works normally, wherein the protection circuit comprises a comparator with a positive and negative terminal, wherein the positive terminal is connected to an end of a feedback element or an end of a first voltage dividing resistor to which a second voltage diving resistor is connected, so as to receive a voltage value which is converted from the current value and is fed back by the feedback element or receive the voltage value obtained by a voltage division of the output voltage by the first and second voltage dividing resistors, wherein the negative terminal is configured to be an input with a predetermined threshold, so as to compare the received voltage value converted from the current value or the received voltage value obtained by the voltage division of the output voltage with the predetermined threshold.

A method of utilizing a timer based protection circuit, comprising:

• acquiring a working current or an output voltage of a protected object;
• comparing a voltage value converted from a current value of the working current or a voltage value of the acquired output voltage with a predetermined threshold;
• when the voltage value converted from the current value of the working current or the voltage value of the acquired output voltage is greater than or equal to the predetermined threshold, resetting, by the protection circuit, the timer to cause the timer to output a low voltage level;
• and when the voltage value converted from the current value of the working current or the voltage value of the acquired output voltage is less than the predetermined threshold, keeping the timer to work normally, wherein the protection circuit comprises a comparator with a positive and negative terminal, wherein the positive terminal is connected to an end of a feedback element or an end of a first voltage dividing resistor to which a second voltage diving resistor is connected, so as to receive a voltage value which is converted from the current value and is fed back by the feedback element or receive the voltage value obtained by a voltage division of the output voltage by the first and second voltage dividing resistors, wherein the negative terminal is configured to be an input with a predetermined threshold, so as to compare the received voltage value converted from the current value or the received voltage value obtained by the voltage division of the output voltage with the predetermined threshold.