Electric circuit for portable heater

• US 6,940,051 B2
• Filed: 06/26/2003
• Issued: 09/06/2005
• Est. Priority Date: 10/01/2001
• Status: Expired due to Term

• Current Assignee: Art K. Tateishi
• Original Assignee: Art K. Tateishi
• Inventors: Tateishi, Art K.
• Primary Examiner(s): PASCHALL, MARK H
• Application Number:
  US10/603,775
• Publication Number:
  US 20040084440A1
• Time in Patent Office: 803 Days
• Field of Search: 219/483, 219/486, 219/485, 219/501, 219/505, 219/491, 219/507, 219/508, 392/360, 392/361, 392363-370
• US Class Current: 219/508
• CPC Class Codes: F24H 15/128 Preventing overheating
• CPC Class Codes: F24H 15/208 Temperature of the air after heating
• CPC Class Codes: F24H 15/281 Input from user
• CPC Class Codes: F24H 15/35 Control of the speed of fans
• CPC Class Codes: F24H 15/37 of electric heaters
• CPC Class Codes: F24H 15/395 Information to users, e.g. alarms
• CPC Class Codes: F24H 3/0417 portable or mobile
• CPC Class Codes: F24H 9/2071 using electrical energy supply

Abstract

A heater effectively uses a current controlled fan motor in series with a resistance heating arrangement. The fan motor preferably is wound with a gauge of wire to appropriate for the relatively high current provided to the fan motor. This arrangement is effectively used to adjust the fan speed to match the heat output when the heating arrangement has variable heat output. More desirable operating characteristics are achieved without increasing costs and fan motor manufacturing savings are realized. The portable heater preferably produces heat at different outputs and the current used to power the resistance heating arrangement is used to power the fan motor.

Claims

1. An electrical circuit for connection to a conventional domestic 120 volt source having a current carrying capacity of 15 amperes for powering a current controlled induction motor while generating heat, said circuit comprising a resistor means whose value can be selected connected in series with said motor, the selected value of said resistor means being such as to provide on connection of said circuit to said source, a current flow through said resistor means to produce a voltage drop thereacross just less than the source voltage, said current controlled motor having coil windings of fewer than 50 and at least about 28 turns of wire of a wire size to accept a current of up to about 15 amperes without heating, whereby the current through said resistor means whose value has been selected determines motor speed.

2. A circuit as claimed in claim 1 in which said wire size of said motor windings is of the order of 14 to 18 gauge wire.

3. A circuit as claimed in claim 1 or 2 in which the number of turns of said motor windings are fewer than 40 turns.

4. A circuit as claimed in claim 1 or 2 in which said motor is a shaded 2 pole induction motor in which the number of turns of said coil windings are fewer than 20 turns per pole.

5. A circuit as claimed in claim 1 in which said motor is a shaded 4 pole induction motor having fewer than 10 turns of wire per pole.

6. A circuit as claimed in claim 1, or 5 in which said resistor means includes a first resistor and a second resistor connected in parallel through a first thermostat connected to interrupt current flow through said first resistor and a second thermostat in series with said first thermostat for interrupting current flow through said second resistor, said second thermostat being selected to interrupy current flow to said second resistor at a slightly lower temperature than the temperature at which said first thermostat interrupts current flow to said first resistor to provide an automatic heat control motor speed change system.

7. A current controlled induction motor for driving a fan in a heater circuit to be connected to a domestic voltage source where a resistor heater means forms an electrical load having a value to provide on connection of the circuit to the source a voltage drop across said load just less than the voltage of the source, said motor having coil windings for connection in series with the resistor heater means and the source whereby current flowing through the heater means flows through said motor coil windings, said coil windings having fewer than 50 and at least about 28 turns and being a wire size of the order of 14 to 18 gauge to accept heater current of at least 12.5 amperes without heating.

8. A motor as claimed in claim 7 in which said motor is a shaded 2 pole induction motor in which the number of turns of said motor windings comprises at least 14 turns per pole.

9. A current controlled induction motor for series connection with a load which on connection to a domestic voltage source provides a voltage drop across the load just less than the voltage of the source, said motor having windings of fewer than 50 and at least about 28 turns, said windings being of 14 to 18 gauge wire having a current carrying capacity of at least 12.5 amperes without heating.

10. A current controlled induction motor as claimed in claim 9 in which said motor is a two pole motor and said motor windings comprise fewer than 20 turns per pole.

11. A current controlled induction motor as claimed in claim 10 in which said motor speed is of the order of 1100 r.p.m. when said load is a 500 watt heater.

12. A current controlled induction motor as claimed in claim 10 in which said motor speed is of the order of 1800 r.p.m. when said load is a 1000 watt heater.

13. A current controlled induction motor as claimed in claim 10 in which said motor speed is of the order of 2800 r.p.m. when said load is a 1500 watt heater.