(JP9079029-A)      An electrically heated catalyst (6) mounted on a vehicle is connected to a power source (8,9),the alternator, as the engine is started. The maximum amount of power is supplied for a predetermined time till just before the catalyst is activated.    A second power source, the battery, then interrupts the first and the resistance of the catalyst measured for a second predetermined period of time long enough to activate it. The amount of power supplied from the battery is controlled by feedback through a switch and is based upon the measured resistance keeping it at a predetermined level.    ADVANTAGE -   Increased reliability of catalyst heating.    (US6052988-A)      An electrically heated catalyst (6) mounted on a vehicle is connected to a power source (8,9),the alternator, as the engine is started. The maximum amount of power is supplied for a predetermined time till just before the catalyst is activated.    A second power source, the battery, then interrupts the first and the resistance of the catalyst measured for a second predetermined period of time long enough to activate it. The amount of power supplied from the battery is controlled by feedback through a switch and is based upon the measured resistance keeping it at a predetermined level.    ADVANTAGE -   Increased reliability of catalyst heating.    (JP3158988-B2)      An electrically heated catalyst (6) mounted on a vehicle is connected to a power source (8,9),the alternator, as the engine is started. The maximum amount of power is supplied for a predetermined time till just before the catalyst is activated.    A second power source, the battery, then interrupts the first and the resistance of the catalyst measured for a second predetermined period of time long enough to activate it. The amount of power supplied from the battery is controlled by feedback through a switch and is based upon the measured resistance keeping it at a predetermined level.    ADVANTAGE -   Increased reliability of catalyst heating.