An igniter circuit for an arc discharge lamp comprises a DC to AC converter, a transformer, an AC to DC converter and high-voltage DC energy storage which is capable of discharging electrical energy to ignite the arc discharge lamp. The present invention makes the message queuing software more efficient by eliminating the transmission of invalid messages through the message channels. The housing assembly includes a housing back, a housing front, and peripheral housing edging. Therefore, the heat generated by the electronic component can be reliably radiated by heat conduction to the carbon layer and heat diffusion through the carbon layer, thereby cooling the electric component with high efficiency. A switch can have a first setting and a second setting.