An input circuit operating at a predetermined power supply voltage can level shift a high voltage input signal from a higher voltage value to the lower power supply voltage level. Inside the chamber there may be placed a catalyst of at least one reaction for oxidizing the inflammable gases by oxygen contained in the chamber atmosphere, supported by an inert solid support; a catalyst of at least the reaction for oxidizing CO to CO2; possibly an oxygen source; and possibly a hygroscopic microporous inert solid support. The rail has multiple through holes and is connected with the L-shaped anti-slip member to limit the movement of the drawer.