DISPOSITIVO DE ASEGURADO POSITIVO DE ADMISION DE GAS EN UN QUEMADOR

LA PRESENTE INVENCION SE REFIERE A UN DISPOSITIVO DE PROTECCION DE QUEMADOR (5) PARA ENCENDIDO DE LLAMA, DETECCION DE LLAMA Y CONTROL DE ADMISION DE GAS CARACTERIZADO PORQUE LLEVA: AS HACIA UN QUEMADOR (5) MAS QUE CUANDO UNA DIFERENCIA DE TENSIONES ENTRE SUS TERMINALES ES SUPERIOR A LA TENSION DE ALIMENTACION; Y DAPTADO PARA APLICAR ENTRE LOS TERMINALES DEL MEDIO DE ADMISION DE GAS (25, 42, 43) UNA TENSION SUPERIOR A LA TENSION DE SALIDA DE LA FUENTE DE ALIMENTACION (8), DE MANERA QUE UN EVENTUAL MAL FUNCIONAMIENTO DE DICHO CIRCUITO DE ALIMENTACION (7) IMPIDA EL PASO DEL GAS A TRAVES DEL MEDIO DE ADMISION DE GAS. The burner admission valve (25) is initially opened by a boost-type control circuit (27), having 1W output, via a self-resetting bi-metal (SRC), guarding against flue obstruction. A second boost circuit (24), with 30 mW output, keeps the valve open. Both circuits give higher output voltages than the battery which provides power supplies, and the latter is insufficient to operate the valve. The burner is lit by a spark generator (20), based on an oscillator (21) and a discharge circuit (22) giving a 15 kV output for 5 microseconds; this is associated with a flame detector (11) using the diode effect of ionisation. These devices are directed at an igniter gas nozzle near the burner. The equipment is further described in European Patent 0 821 198 (q.v.).