Fire alarm systems

A strobe notification appliance comprising:

• a boost circuit connected to an input voltage of the strobe notification appliance to supply electric energy;
• an energy storage circuit charged by the boost circuit;
• a drive circuit powered by the energy storage circuit to generate a drive current;
• an LED circuit with a plurality of LED elements connected in a series configuration supplying the drive current to the LED elements;
• a first sampling circuit collecting an overall voltage drop of the plurality of LED elements in the LED circuit;
• a control circuit connected to the drive circuit and configured to adjust the drive circuit to supply a working current during an alarming stage and supply a detection current during a detection stage;
• and
• a second sampling circuit collecting energy storage voltages on two ends of a capacitor in the energy storage circuit;
• wherein the detection current is lower than the working current and thereby light energy produced by the LED elements during the detection stage is lower than alarming light energy produced during the alarming stage;
• wherein the control circuit further, during the detection stage, determines whether the LED circuit works normally based on the collected overall voltage drop;
• and
• wherein the control circuit determines an actual eigenvalue of the capacitor according to the energy storage voltages sampled by the second sampling circuit and a sampling time interval.

A strobe notification appliance comprising:

• a boost circuit connected to an input voltage of the strobe notification appliance to supply electric energy;
• an energy storage circuit charged by the boost circuit;
• a drive circuit powered by the energy storage circuit to generate a drive current;
• an LED circuit with a plurality of LED elements connected in a series configuration supplying the drive current to the LED elements;
• a first sampling circuit collecting an overall voltage drop of the plurality of LED elements in the LED circuit;
• and
• a control circuit connected to the drive circuit and configured to adjust the drive circuit to supply a working current during an alarming stage and supply a detection current during a detection stage;
• wherein the drive circuit comprises:
• a working current generation circuit supplying the working current for the LED circuit to emit alarming light;
• a detection current generation circuit supplying the detection current for the LED circuit;
• and
• a toggle switch selectively transferring the electric energy from the energy storage circuit to one of the working current generation circuit and the detection current generation circuit;
• wherein the control circuit is connected to the toggle switch and the toggle switch switches in response to a signal from the control circuit;
• wherein the detection current is lower than the working current and thereby light energy produced by the LED elements during the detection stage is lower than alarming light energy produced during the alarming stage;
• and
• wherein the control circuit further, during the detection stage, determines whether the LED circuit works normally based on the collected overall voltage drop.