AGENCEMENT DE COMMANDE A TOUCHES POUR APPAREIL ELECTRIQUE

LA PRESENTE INVENTION CONCERNE UN CIRCUIT DE COMMANDE POUR UN APPAREIL DU TYPE COMPRENANT UNE CHARGE ELECTRIQUE DESTINEE A ETRE ALIMENTEE PAR UNE SOURCE D'ALIMENTATION EXTERNE.CE CIRCUIT COMPREND UN CLAVIER 68 COMPRENANT UNE PLURALITE DE MOYENS COMMUTATEURS MANOEUVRABLES PAR L'UTILISATEUR 24A-24D, 26A-26D, 28A-28D, 29 COMPRENANT UN PREMIER MOYEN COMMUTATEUR DE SELECTION D'ETAT (MARCHE: ON) ET UN SECOND MOYEN COMMUTATEUR DE SELECTION D'ETAT (ARRET: OFF); UN MOYEN DE COMMANDE ELECTRONIQUE 60 COMPRENANT UN MOYEN DE BALAYAGE 64, 66 ACTIF POUR VALIDER PERIODIQUEMENT CERTAINS AU MOINS DES MOYENS COMMUTATEURS Y COMPRIS LE COMMUTATEUR ON POUR DETECTER UNE MANOEUVRE DE CELUI-CI PAR L'UTILISATEUR; ET UN MOYEN VC POUR VALIDER DE FACON CONSTANTE LE COMMUTATEUR OFF. LE COMMUTATEUR ON AGIT QUAND IL EST ACTIONNE ET VALIDE, POUR ALIMENTER LA CHARGE. LE COMMUTATEUR OFF AGIT QUAND IL EST ACTIONNE, POUR COUPER L'ALIMENTATION INDEPENDAMMENT DU MOYEN DE BALAYAGE.APPLICATION A LA COUPURE DE PLAQUES CHAUFFANTES D'UNE CUISINIERE ELECTRIQUE. An improved touch control circuit arrangement for electrical appliances having one or more electrical loads to be individually controlled in accordance with user selected power settings. Each load has associated with it a power relay for coupling the load to an external power supply. Each relay is coupled to a latch circuit operative when set to close the relay and when reset to open the relay. The touch control arrangement includes a matrix array of touch keys having an input line for each row and an output line for each column to facilitate the multiplexing of touch key information to the microprocessor in conventional fashion. However, the OFF keys are continuously enabled and coupled to the reset input of the associated latch circuit such that user actuation of an OFF key directly resets the relay control circuit for the associated load. This enables the user to turn off the load independent of the microprocessor. Each ON key is coupled to the set input of its associated latch circuit such that both actuation of the ON key and an enable signal from the microprocessor are required to set the latch circuit. This prevents the inadvertent closure of the relays such as might otherwise result from microprocessor failure.