초록 ▼

A coffeemaker is provided with a power circuit and a control circuit. The power circuit is connected to a household source of electric power and it is activated by a relay switch. The control circuit includes a relay coil for the switch, and a triac that may be triggered into conduction when a turn

A coffeemaker is provided with a power circuit and a control circuit. The power circuit is connected to a household source of electric power and it is activated by a relay switch. The control circuit includes a relay coil for the switch, and a triac that may be triggered into conduction when a turn on signal from an electronic timer module is applied to the control terminal of the triac simultaneously with the application of direct current control circuit voltage across the triac. Thereafter, the triac remains in its conductive state so long as the direct current flowing through the triac remains above a minimum level. Subsequent removal of the turn on signal from the control terminal of the triac has no effect on the operation of the power circuit which includes the coffeemaker heating means so long as the direct current flowing through the triac remains above a minimum level.

대표청구항 ▼

In a coffeemaker, improved heating and control means comprising: (a) a power circuit for connection to a source of electric power, said power circuit comprising heating means and a first switching means having a normally non-conductive state and a conductive state; (b) a control circuit for connecti

In a coffeemaker, improved heating and control means comprising: (a) a power circuit for connection to a source of electric power, said power circuit comprising heating means and a first switching means having a normally non-conductive state and a conductive state; (b) a control circuit for connection to a source to direct current electric power, said control circuit comprising activating means and a semiconductor switching means having a normally non-conductive state and a conductive state, said semiconductor switching means having a control terminal and assuming its conductive state only when a turn on signal is supplied to said control terminal simultaneously with the application of direct current voltage across said semiconductor switching means and said semiconductor switching means thereafter remaining in its conductive state so long as the direct current flowing through said control circuit remains above a minimum level: (c) said activating means being operatively connected to said first switching means to place and maintain said first switching means in its conductive state only in response to flow of electric current through said control circuit and said activating means; and (d) means for supplying a turn-on signal to said control terminal of said semiconductor switching means when heating of the coffeemaker is desired, whereby subsequent removal of the turn-on signal from said control terminal has no effect on operation of said power circuit and said heating means so long as the direct current flowing through said control circuit remains above said minimum level.