Integrally printed blower speed resistor circuit on evaporator

Abstract

An evaporator for dissipating heat from a heating, ventilation and air conditioning (HVAC) system has a first side plate and a second side plate. The second side plate is spaced apart and parallel to the first side plate. An electronic circuit for controlling the HVAC system is printed on the first side plate.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention relates to a heating, ventilation and air conditioning system (HVAC), and more particularly, to an evaporator apparatus for dissipating heat from the HVAC system.

2. Description of the Prior Art

An automobile heating, ventilating and air conditioning system (HVAC) generally includes a blower motor. Furthermore, the HVAC system generally includes a control module such as a linear power module, a pulse width modulator, or a relay resistor module which provides variable speed control of the blower motor. A disadvantage of these control modules is that they generate a significant amount of heat that must be dissipated to conserve the life of the module. A common mode of dissipating heat requires that a heat sink be attached to each power control module, and that the heat sink be inserted into the air flow of the HVAC system to cool the electronic components inside each power control module. An example of a heat sink and a control module as specified is shown in U.S. Pat. No. 5,012,656, issued to Yasuji Tamura.

Placing the heat sink and its respective control module into the air flow of the HVAC can produce objectionable tonal noises.

SUMMARY OF THE INVENTION AND ADVANTAGES

The present invention is an evaporator apparatus for dissipating heat from a heating, ventilation and air conditioning (HVAC) system. The apparatus includes an evaporator having a first side plate and a second side plate spaced apart and parallel to the first side plate. The invention is distinguished by an electronic circuit for controlling the HVAC system being printed on the first plate of the evaporator.

The present invention eliminates the need for a separate resistor card by printing the electronic circuit, i.e., the resistor circuit, on the first plate of the evaporator. As a result, the evaporator essentially functions as an effective heat sink thereby eliminating the need to put a resistive speed controller near a throat area of the diffuser. Thus, the present invention provides an evaporator apparatus which results in reduced tonal noise output.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a partial view of a heating, ventilation, and air conditioning module of an automobile;

FIG. 2 is a block diagram of a refrigeration, or cooling, circuit of the automobile air conditioning system; and

FIG. 3 is a perspective view of an evaporator of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, a heating, ventilation, and air conditioning (HVAC) system is shown generally at 20 in FIG. 1.

HVAC system 20 includes a compressor 22 for compressing a refrigerant, and a condenser 24 for receiving the refrigerant from the compressor 22 and condensing the refrigerant. HVAC system 20 also includes an expansion device 25 for receiving the refrigerant from the condenser 24. The expansion device 25 expands the high pressure liquid refrigerant from the condenser 24 into a low pressure liquid and vapor mixture before it enters an evaporator 26 (also referred to throughout as an evaporator 26 apparatus) used for evaporating the refrigerant. More particularly, the evaporator 26 apparatus provides the function of absorbing heat from the air entering the vehicle passenger compartment which will then be dissipated by the condenser 24. The evaporator 26 also has the function of directly absorbing the heat generated during the voltage reduction of the speed controller for the blower motor. Referring to FIG. 2, a circuit 28 interconnects the compressor 22 and the condenser 24 and the expansion device 25 and the evaporator 26 for directing the refrigerant there through in a particular direction as shown by the arrows bordering the circuit 28.

As shown in FIG. 3, the evaporator 26 has a first side plate 30 and a second side plate 32 that is spaced apart and parallel to the first side plate 30. The evaporator 26 is distinguished by having an electronic circuit 34, also referred to as a resistor circuit or as the blower motor control circuit, for controlling the HVAC system 20 printed on the first side plate 30. The electronic circuit 34 is directly printed onto the first side plate 30 such that the evaporator 26 operates as a heat sink for waste heat that is generated as voltage to the blower is reduced to achieve the various desired speeds. Preferably, the electronic circuit 34 is covered with an epoxy (not shown) to protect the surface of the electronic circuit 34. However, the electronic circuit 34 may be covered by other materials suitable for protecting the surface of the electronic circuit 34. The electronic circuit 34 provides variable speed control for the blower motor (not shown) of the HVAC system 20. During operation, the HVAC system 20 generates a substantial amount of heat. The heat is dissipated into the evaporator 26 core.

The evaporator 26 also includes an electrical connector 36 that is supported on the first plate 30 and electrically coupled to the electronic circuit 34. A pair of spaced header tanks 38 and tubes 40 extending between the header tanks 38 are further included with the evaporator 26. The side plates 30, 32 of the evaporator 26 interconnect the header tanks 38. The evaporator 26 also includes a plurality of cooling fins 42 that separate the tubes 40 between the header tanks 38. An inlet 44 extends into one of the tanks 38 and an outlet 46 extends from the other tank 38.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims.

Claims

1. An evaporator apparatus for dissipating heat from a heating, ventilation and air conditioning (HVAC) system comprising: an evaporator having a first side plate and a second side plate spaced apart and parallel to said first side plate, and an electronic circuit for controlling said HVAC system printed on said first side plate.

2. An apparatus as set forth in claim 1 including an electrical connector supported on said first plate and electrically coupled to said electronic circuit.

3. An apparatus as set forth in claim 2 wherein said evaporator includes a pair of spaced header tanks and tubes extending between said header tanks and said side plates interconnect said header tanks.

4. An apparatus as set forth in claim 3 including a plurality of cooling fins separating said tubes between said header tanks.

5. An apparatus as set forth in claim 3 including an inlet into one of said tanks and an outlet extending from the other of said tanks.

6. A heating, ventilation and air conditioning (HVAC) system comprising: a compressor for compressing a refrigerant, a condenser for receiving the refrigerant from said compressor and condensing the refrigerant, an expansion devise for receiving the condensed refrigerant from said condenser, an evaporator for receiving the refrigerant from said condenser and evaporating the refrigerant, said evaporator having a first side plate and a second side plate spaced apart and parallel to said first side plate, a circuit interconnecting said compressor and said condenser and said expansion device and said evaporator for directing the refrigerant therethrough in a direction, and an electronic circuit for controlling said HVAC system printed on said first side plate.

7. An apparatus as set forth in claim 6 including an electrical connector supported on said first side plate and electrically coupled to said electronic circuit.

8. An apparatus as set forth in claim 7 wherein said evaporator includes a pair of spaced header tanks and tubes extending between said tanks and said side plates interconnect said header tanks.

9. An apparatus as set forth in claim 8 including a plurality of cooling fins separating said tubes between said header tanks.

10. An apparatus as set forth in claim 9 including an inlet into one of said tanks and an outlet extending from the other of said tanks.