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US 5,396,047 AGranted
Electric heating unit with alternately heated surface areas
AssigneeE.G.O. Elektro-Gerate Blanc u. Fischer
InventorsWilfried Schilling, Robert Kicherer
Life of this patent
Estimating the term…
Abstract
A heating unit (1) for a cooking point has an outer heater (3) and an inner heater (4) located concentrically for separately heating an associated surface area (13, 14) of the overall heating surface (2). The two heaters (3, 4) can be differently regulated such that supplied power is periodically switched over and distributed in very short, but variable time intervals in a continuously alternating manner to the two heaters (3, 4). Switching over takes place in the passage of the alternating current characteristic through the zero line. Thus, without influencing a clicking rate, there can be a random power distribution on at least two surface areas (13, 14) of the same heating surface (2) and a high efficiency with a relatively simple control (10).
Claims36
An electric heating unit comprising:
- at least one heating surface (2) defining separately heatable first and second surface areas for delivering thermal energy;
- at least two electric heaters (3, 4), each having an individual rated operating capacity and each mainly heating one of said first and second surface areas (13, 14);
- and
- control means (10) for alternately delivering operating power to each of said electric heaters (3, 4) to provide first and second temperature levels during heating operation, said control means (10) including temperature sensing means (7, 8),
- said control means separately thermally controlling said at least two surface areas (13, 14), said control means simultaneously substantially individually detecting and comparing withdrawal of thermal energy from said first and second surface areas, wherein said control means (10) is provided for reciprocating power supply to said at least two electric heaters (3, 4) in intervals, said control means withdrawing a first quantity of said operating power from said first electric heater and delivering said first quantity to said second electric heater when said sensing means detects a decrease of said first temperature level below a predetermined value, thereby raising supply of said operating energy to said second electric heater with respect to supply of operating energy to said first electric heater, said control means withdrawing a second quantity of said operating energy from said second electric heater and delivering said second quantity to said first electric heater when said sensing means detects a drop of said second temperature level below a predetermined value, thereby raising supply of said operating energy to said first electric heater with respect to a supply of operating energy to said second electric heater.
2 more elements
An electric heating unit comprising:
- at least one heating surface (2) defining separately heatable first and second surface areas for delivering thermal energy;
- at least two electric heaters (3, 4), each having an individual rated operating capacity and each mainly heating one of said first and second surface areas (13, 14);
- and
- control means (10) for alternately delivering operating power to each of said electric heaters (3, 4) to provide first and second temperature levels during heating operation, said control means (10) including temperature sensing means (7, 8),
- said control means separately thermally controlling said at least two surface areas (13, 14), said control means simultaneously substantially individually detecting and comparing withdrawal of thermal energy from said first and second surface areas, wherein said control means (10) operates as a detecting means for detecting presence of an article in the vicinity of said heating surface (2).
2 more elements
An electric heating unit comprising:
- at least one heating surface (2) defining separately heatable first and second surface areas for delivering thermal energy;
- at least two electric heaters (3, 4), each having an individual rated operating capacity and each mainly heating one of said first and second surface areas (13, 14);
- and
- control means (10) for alternately delivering operating power to each of said electric heaters (3, 4) to provide first and second temperature levels during heating operation, said control means (10) including temperature sensing means (7, 8),
- said control means separately thermally controlling said at least two surface areas (13, 14), said control means simultaneously substantially individually detecting and comparing withdrawal of thermal energy from said first and second surface areas, wherein said control means (10) simultaneously maintains said heaters (3, 4) in said heating operation, said operating power being alternately delivered to said heaters at a constant power value.
2 more elements
An electric heating unit comprising:
- at least one heating surface (2) defining separately heatable first and second surface areas for delivering thermal energy;
- at least two electric heaters (3, 4), each having an individual rated operating capacity and each mainly heating one of said first and second surface areas (13, 14), and
- control means (10) for alternately delivering operating power to said electric heaters (3, 4) to provide first and second temperature levels in heating operation, said control means (10) including temperature sensing means (7, 8),
- said control means (10) including temperature sensing means, said control means separately thermally controlling said at least two surface areas (13, 14) said control means simultaneously substantially individually detecting and comparing withdrawal of thermal energy from said first and second surface areas, wherein at least two of said electric heaters (3, 4) are juxtaposed in a common plane.
1 more element
An electric heating unit comprising:
- at least one heating surface (2) defining separately heatable first and second surface areas for delivering thermal energy;
- at least two electric heaters (3, 4), each having an individual rated operating capacity and each mainly heating one of said first and second surface areas (13, 14);
- and
- control means (10) for alternately delivering operating power to each of said electric heaters (3, 4) to provide first and second temperature levels during heating operation, said control means (10) including temperature sensing means (7, 8),
- said control means separately thermally controlling said at least two surface areas (13, 14), said control means simultaneously substantially individually detecting and comparing withdrawal of thermal energy from said first and second surface areas, wherein at least one of elements provided by at least one of said electric heaters (3, 4) and at least one temperature sensor (11, 12) of said temperature sensing means (7, 8) is at least partly provided by a thick-film resistor substantially arranged in an alternating course.
2 more elements
An electric heating unit comprising:
- at least one heating surface (2) defining separately heatable first and second surface areas for delivering thermal energy;
- at least two electric heaters (3, 4), each having an individual rated operating capacity and each mainly heating one of said first and second surface areas (13, 14), and
- control means (10) for alternately delivering operating power to said electric heaters (3, 4) to provide first and second temperature levels in heating operation, said control means (10) including temperature sensing means (7, 8),
- said control means (10) including temperature sensing means, said control means separately thermally controlling said at least two surface areas (13, 14) said control means simultaneously substantially individually detecting and comparing withdrawal of thermal energy from said first and second surface areas, wherein only two of said electric heaters (3, 4) are provided, said electric heaters (3, 4) defining only two of said surface areas (13, 14) having annular configurations and defining an unheated center of said heating surface (2).
1 more element
Dependencies are inferred from the claim text.