EP1113706B1 - Continuously adjustable method of temperature in an electrical heating device suitable for a vehicle - Google Patents

Description

The invention relates to a device for stepless adjustability of Temperature of an electric heater for a vehicle, wherein the Electric heater in particular by one or more transistor-controlled PTC elements is.

Are known devices for adjusting a temperature of an electric heater in the vehicle, according to DE 19733045 C1, by detecting and Rules of the transistor currents reach an operating point stabilization. These Devices have the disadvantage that the current is still no statement about the actual transistor temperature provides and further necessary for the measurement Shunts are tolerant and costly.

The invention has for its object to provide a device for adjusting the Temperature of an electric heater in a vehicle to create, with the temperature continuously without significant circuitry effort or virtually infinitely adjustable.

• dass die vom Temperatursensor ermittelte Temperatur auf einen vorgebbaren Wert regelbar ist.

To solve this problem, the invention proposes a device for the continuous adjustability of the temperature of an electric heater in a vehicle, in which one or more heating elements are supplied in particular steplessly with electrical energy via one or more transistors, wherein each transistor is a temperature sensor for determining the temperature associated with the transistor, its housing or its substrate. In this device, the invention provides
a controller is connected to a temperature control loop and

• that the temperature determined by the temperature sensor can be regulated to a predefinable value.

Thus, according to the invention, the driving of each transistor takes place in such a way that that the transistors are kept at predeterminable temperatures. Of the Operating point of the transistors is determined according to their temperatures.

Advantageously, the chip temperature control circuit according to the invention is as subordinate control circuit in a main control circuit for the control of the middle Radiator temperature integrated.

It is advantageous if the main control loop is designed such that it to the subordinate temperature control circuits setpoint values for the temperature of the transistor, his housing or his substrate pretending to be the same, are equal or different in groups to the mean temperature of the Electric heater and / or a temperature gradient to be applied to the electric heater to regulate. This allows the electric heater on any adjust adjustable temperature gradient. When using such a regulated Electric heater in the air conditioning of a vehicle with e.g. driver and Passenger side separately specifiable temperatures can thus due to the driver / passenger wishes required temperature gradient of the air flow be built by the electric heater, so that in these air conditioners required second mixing flap with servomotor (air-side temperature control) or the second heating medium flow control valve with actuator (water-side temperature control) in addition to the wiring can be omitted.

Another advantage of the invention is the fact that the regulation of Chip temperatures allows parallel operation of multiple transistors at automatically dissipates the power dissipation to the transistors distributed.

The elements of the inner control circuit or the inner control circuits can lie in the transistor housing and / or outside of the transistor housing.

An embodiment of the invention results from the circuit according to the drawing whose individual components are designated accordingly. It should be remembered that only a subordinate transistor temperature control loop is shown. In case of building the electric heater with a plurality of heating elements and a plurality of transistors are the individual control circuits connected in parallel with each other and the parent Main control loop underlaid.

Claims (5)

1. A device for continuously adjusting the temperature of an electric heater in a motor vehicle, comprising

   at least one heating element, and

   at least one transistor for supplying electric power to the at least one heating element,

   a temperature sensor for detecting the temperature of the transistor, its housing and/or its substrate is associated to each transistor,

   characterized in

   that each transistor is connected with the associated temperature sensor as an actual value transducer and with a controller to form a temperature control loop, and

   that the temperature detected by the temperature sensor is controllable to a target temperature value adapted to be set by a target value transducer.
2. The device of claim 1, wherein the temperature control loops are integrated into a main control loop as subordinate control loops.
3. The device of claim 2, wherein the main control loop is configured such that it provides target values of the temperature of the transistor, its housing and/or its substrate to the subordinate temperature control loops, which values are similar to each other, similar in groups or different, so as to control the mean temperature of the electric heater and/or a temperature gradient to be impressed on the electric heater.
4. The device of one of claims 1 to 3, wherein the control of the chip temperatures allows for a parallel operation of a plurality of transistors, wherein the desired temperature distribution is automatically distributed uniformly over the transistors.
5. The device of one of claims 1 to 3, wherein the components of a temperature control loop may be located within or without the transistor housing.

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