Dryer with universal voltage controller
View Patent ↗A hand dryer comprising a universal brushed AC blower vacuum motor, one or more resistive circuits of a heating element, and a universal voltage controller that selectively alternates the configuration and the electrical connection of the resistive circuits, in response to a detected input voltage is disclosed.
1. A hand dryer configured to accept multiple voltage inputs, the hand dryer comprising:
a blower vacuum motor for producing output air;
a heating element for heating the output air, the heating element comprising a plurality of resistors configured to form a plurality of resistive circuits, each of the plurality of resistive circuits in one of series and parallel with the blower vacuum motor; and
a voltage controller for selecting a nominal voltage supplied to the blower vacuum motor via the plurality of resistors of the heating element, the voltage controller selecting the nominal voltage based on an input voltage by operating one or more relays to independently select one of the plurality of resistive circuits.
2. The hand dryer as recited in claim 1 , wherein the plurality of resistive circuits comprises a first resistive circuit, a second resistive circuit, and a third resistive circuit, and the plurality of resistors comprises a first resistor and a second resistor.
3. A hand dryer configured to accept multiple voltage inputs, the hand dryer comprising:
a blower vacuum motor for producing output air;
a heating element for heating the output air, the heating element comprising a first resistor and a second resistor;
a voltage controller for selecting a nominal voltage supplied to the blower vacuum motor, the voltage controller selecting the nominal voltage based on an input voltage by operation of one or more relays to select a first resistive circuit, a second resistive circuit, or a third resistive circuit;
the first resistive circuit has the first resistor and the second resistor in series with each other and in parallel with the blower vacuum motor;
the second resistive circuit has the first resistor in series with the blower vacuum motor and the second resistor is not in series with the blower vacuum motor; and
the third resistive circuit has the first resistor and the second resistor in series with the blower vacuum motor.
4. The hand dryer as recited in claim 3 , wherein the first resistive circuit has a first circuit resistance and the second resistive circuit has a second circuit resistance, the second circuit resistance being greater than the first circuit resistance.
5. The hand dryer as recited in claim 3 , wherein the first resistive circuit has a first circuit resistance and the second resistive circuit has a second circuit resistance, the second circuit resistance being at least ten ohms greater than the first circuit resistance.
6. The hand dryer as recited in claim 3 , further comprising a switch that selectively actuates the one or more relays to select the first resistive circuit, the second resistive circuit, or the third resistive circuit.
7. The hand dryer as recited in claim 6 , further comprising a processor configured to control embedded software that actuates the switch.
8. The hand dryer as recited in claim 6 , wherein the one or more relays comprise at least three relays.
9. The hand dryer as recited in claim 3 , wherein the input voltage has an alternating current (AC) waveform that is maintained in the first resistive circuit, in the second resistive circuit, and in the third resistive circuit.
10. The hand dryer as recited in claim 3 , wherein the second resistive circuit has a second circuit resistance equal to a first resistance of the first resistor.
11. The hand dryer as recited in claim 10 , wherein the third resistive circuit has a third circuit resistance equal to a sum of the first resistance of the first resistor and a second resistance of the second resistor.
12. The hand dryer as recited in claim 3 , wherein the one or more relays are configured to select a resistive circuit from a group consisting of the first resistive circuit, the second resistive circuit, and the third resistive circuit.
13. The hand dryer as recited in claim 3 , wherein the second resistive circuit has a second circuit resistance (RE 2 ) given by:
RE
2
=
RM
×
(
VS
VM
-
1
)
where
RM=a dynamic resistance of the blower vacuum motor;
VS=the input voltage;
VM=the nominal voltage to be supplied to the blower vacuum motor, and
RE 2 is equal to a first resistance of the first resistor.
14. The hand dryer as recited in claim 13 , wherein the third resistive circuit has a third circuit resistance (RE 3 ) given by:
RE
3
=
RM
×
(
VS
VM
-
1
)
where
RM=the dynamic resistance of the blower vacuum motor;
VS=the input voltage;
VM=the nominal voltage to be supplied to the blower vacuum motor, and
RE 3 is equal to a sum of the first resistance of the first resistor and a second resistance of the second resistor.
15. The hand dryer as recited in claim 14 , wherein the input voltage (VS) is selected from the group consisting of 120 VAC, 208 VAC, 240 VAC and 277 VAC.
16. The hand dryer comprising:
a blower vacuum motor for producing output air, the blower vacuum motor having a dynamic resistance;
a heating element for heating the output air, the heating element comprising a first resistor and a second resistor;
a voltage controller for selecting a nominal voltage supplied to the blower vacuum motor, the voltage controller selecting the nominal voltage based on an input voltage by operation of one or more relays to select a first resistive circuit, a second resistive circuit or a third resistive circuit;
the first resistive circuit has the first resistor and the second resistor in series with each other and in parallel with the blower vacuum motor;
the second resistive circuit has the first resistor in series with the blower vacuum motor and the second resistor is not in series with the blower vacuum motor and the second resistive circuit has about a 0.7:1 resistance ration with the dynamic resistance of the blower vacuum motor; and
the third resistive circuit has the first resistor and the second resistor in series with the blower vacuum motor and the third resistive circuit has about a 1:1 resistance ratio with the dynamic resistance of the blower vacuum motor.
17. The hand dryer as recited in claim 16 , where the second circuit has a second circuit resistance (RE 2 ) given by:
RE
2
=
RM
×
(
VS
VM
-
1
)
where
RM=a dynamic resistance of the blower vacuum motor;
VS=the input voltage;
VM=the nominal voltage to be supplied to the blower vacuum motor, and
RE 2 is equal to a first resistance of the first resistor.
18. The hand dryer as recited in claim 17 , wherein the third resistive circuit has a third circuit resistance (RE 3 ) given by:
RE
3
=
RM
×
(
VS
VM
-
1
)
where
RM=the dynamic resistance of the blower vacuum motor;
VS=the input voltage;
VM=the nominal voltage to be supplied to the blower vacuum motor, and
RE 3 is equal to a sum of a first resistance of the first resistor and a second resistance of the second resistor.
19. The hand dryer as recited in claim 16 , wherein the input voltage is selected from the group consisting of 120 VAC, 208 VAC, 240 VAC and 277 VAC.
20. The hand dryer as recited in claim 16 , wherein the nominal voltage to be supplied to the blower vacuum motor is 120 VAC and the input voltage is selected from the group consisting of 208 VAC, 240 VAC and 277 VAC.