A starting method for a Ceramic Discharge Metal-halide (CDM) lamp, wherein the starting method is applied to a starting device for the CDM lamp, the starting device comprises a full bridge inverter connected to the CDM lamp, a driving circuit, a single-chip microcomputer and an ignition determining module, wherein the starting method comprises steps below:
- S100:
- when the starting device is powered up, detecting whether a DC input voltage is present at an input side of the full-bridge inverter;
- if not, determining that the input side of the full-bridge inverter is abnormal;
- if present, proceeding to next step;
- S200:
- if the DC input voltage is present at the input side of the full-bridge inverter, the driving circuit being controlled by the single-chip microcomputer;
- within a set time length T0, continuously outputting a Pulse Width Modulation (PWM) waveform to regulate the full-bridge inverter continuously, according to a certain set period, so that the full-bridge inverter provides output to the CDM lamp;
- S300:
- determining, by the ignition determining module, whether the output provided by the full-bridge inverter within the time length T0 successfully ignites the CDM lamp, and outputting, by the ignition determining module, a result of the determining to the single-chip microcomputer, wherein the ignition determining module is disposed between the full-bridge inverter and the single-chip microcomputer, and the single-chip microcomputer, the ignition determining module and the full-bridge inverter are three separate and distinct components that are not integrated into one part;
- S400:
- if the single-chip microcomputer knows that the ignition succeeds through the step S300, controlling, by the single-chip microcomputer the driving circuit to regulate the output of the full-bridge inverter, so that the CDM lamp enters into a normal working state from a starting state;
- S500:
- if the single-chip microcomputer knows that the ignition failed through the step S300 and the DC input voltage is still present at the input side of the full-bridge inverter, the drive circuit being still controlled by the single-chip microcomputer;
- changing the previously set period, and continuously outputting, according to the changed set period within the time length T0, pulse of the period, so that the full-bridge inverter provides a new output to the CDM lamp;
- then, continuing to execute step S300;
- if the ignition determining module still determines that the ignition failed, executing step S600;
- otherwise, jumping to step S400;
- S600:
- accumulating the time length T0 in the executed step S500 and the time length T0 in the executed step S200, and determining whether the accumulated time length has exceeded a preset total time length T;
- if not, iteratively executing the step S500, wherein during each of the iteratively executing the step S500, an output voltage and an output pulse width of the full-bridge inverter are simultaneously raised so as to obtain an enhanced energy density for facilitating the ignition;
- the ignition determining module senses real-time current flowing through the CDM lamp to obtain real-time sampling data represented by the PWM waveform;
- a fuzzy operation is performed to obtain a fuzzy operation-processed waveform of sensed data obtained from the real-time sampling and to determine that a present CDM current represented by the fuzzy operation-processed waveform is in a state of being a corresponding value in a database;
- and the single-chip microcomputer emits a control signal to control the driving circuit after determining that the present CDM current is in the state of the corresponding value in the database;
- otherwise, switching off pulse output of the driving circuit, confirming that a starting time-out fault is present, and transmitting an alert of starting time-out fault to the single-chip microcomputer.