DE102005020006A1 - Line-free self-powered switching element - Google Patents

Abstract

The invention relates to a line-free energy self-sufficient switching element for preferably use in the interior of motor vehicles. DOLLAR A The lead-free energy self-switching element with a radio transmitter module, which preferably operates in an ISM frequency band and the energy required is preferably provided by a piezoelectric energy converter, consists essentially of a housing with an actuator in which an energy converter in construction, an evaluation circuit and a microcontroller are arranged, wherein the microcontroller (3) is equipped with only one reset pin and at least one data memory and has only one input and one output.

Description

The The invention relates to a line-free energy self-sufficient switching element for one preferably use in the interior of motor vehicles.

From the DE 102 56 156 A1 is an energy-autonomous electromechanical radio switch, known, which has at least one transducer element for converting mechanical energy into electrical energy and at least one actuation field for introducing the mechanical energy and at least one sensor for each actuation field for detecting the switching command and at least one electronics for generating and sending a radio signal and has a mechanism for deflecting the forces introduced by the actuation field on the transducer element.

Of the Disadvantage here is that additional sensors (mechanical Button) are required for the detection of the switching command or for evaluation the direction of actuation needed become.

In the DE 101 55 125 B4 a device for converting mechanical energy into electrical energy is described with a piezoelectric transducer, wherein by a path reduction of the deformation of the deformation mechanism when storing the mechanical energy is greater than in the delivery of mechanical energy to the piezoelectric transducer, so that by the leverage on the piezoelectric transducer acting force is amplified, which is reinforced by the achieved by leveraging factor of Wegverkürzung.

The DE 101 03 952 A1 indicates a device for supplying energy, in particular a sensor, with a piezoelectric transducer, which is deformable by a mechanical energy storage and provides a corresponding electrical voltage, against, in which the passive piezoelectric transducer is bendable by a given from the energy storage deformation work, in which case the Transducer is rod-shaped and its one end of the bar relative to another firmly held rod end in particular in two opposite directions is bendable.

Of the The present invention is therefore based on the object, an improvement for a to create a line-free energy self-sufficient switching element.

According to the invention this Task solved by that at a cable-free energy self-sufficient switching element with a radio transmitter module, in the case of the switching element with an actuating element in unit an energy converter, an evaluation circuit and a Microcontrollers are arranged, the microcontroller with only a reset pin and at least one data memory is populated and has only one input and one output. The start release of the Program sequence in the microcontroller takes place due to the activity the operating voltage applied to the energy converter.

The Evaluation circuit for determining the actuation direction of the actuating element preferably consists of a series resistor and a Zener diode, wherein in one Switching on a switch-on and in the other switching state Off signal is generated and the input (IN) of the microcontroller supplied becomes.

When one of the main advantages of this solution according to the invention to call that the Energy converter not only, as with the known products, the energy production serves, but also for switching signal generation and status determination whether the switching element is pressed or let go.

From Another advantage is that on Reason for the simultaneous use of the energy converter for power supply and for generating the switching signal to the use of further mechanical button for detecting the switching state omitted can be and thus the mechanically operated button own disadvantages can be excluded.

advantageous Further developments and refinements of the invention are evident from the remaining subclaims and from the principle described below with reference to the drawings embodiment seen.

It demonstrate

1 a representation of the basic principle of the circuit-free switching element;

2 : An illustration of the block diagram of the line-free switching element.

The 1 shows a representation of the basic principle of the line-free switching element.

For the structural design of a circuit-free switching element, which is to be used in the interior of a motor vehicle, becomes a combination of an energy converter 1 , preferably a piezo transducer, for autonomous power supply and an electromagnetic signal transmission in the 868 MHz SRD band selected.

The actuated via an actuator piezoelectric transducer 1 generates on actuation a certain amount of energy, which by a voltage converter 2 in one for the microcontroller 3 and for the RF module 4 suitable form is converted. By evaluating the pulse shape of the voltage generated, the microcontroller 3 if necessary distinguish between the states "actuator pressed" or "released". This also applications can be realized in which the switching function of devices on the operating duration of the actuating element is dependent.

After actuation of the actuating element and the associated power supply and generation of the on or off signal generates the microcontroller 3 a stored in the memory transmission message with a unique identifier, and the on or off information.

This send telegram then becomes in the RF module 4 modulated and over the interface (antenna) 5 sent.

Around the transmission security to increase exists the possibility, Send the transmission telegram several times in very short time intervals in succession.

The Use of the 868 MHz SRD band for data transmission offers an advantage across from others to the public Use shared frequency bands. The advantage is a fixed duty cycle of 1%, i. with an assumed telegram transmission duration from approx. 3 to 4 ms, including 2 repetitions, the switching element can operated up to 9000 times per hour.

By The duty cycle reduces mutual interference to a minimum. Due to the very short transmission telegrams, many stations in one Cell are operated without the probability of collision increases.

The use, for example, of a 32-bit identifier allows the receiving modules to differentiate between 2 ³² transmitters, ie 4,295 billion transmitters can be distinguished. This means that with about 20 switching elements per motor vehicle, over 214 million vehicles can be operated with circuit-free switching elements in the same frequency band.

The Information of the send telegram is in a downstream Controller, that is outside of the switching element according to the invention located, assigned to various switching functions. Possible are for example, the on / off function or a time-dependent one Switching function.

The realization of the aforementioned constructive solution of a line-free switching element for the interior of motor vehicles takes place according to the block diagram according to 2 ,

By pressing the actuator is the piezoelectric transducer 1 actuates and generates a positive pulse, which is passed through a rectifier circuit. The downstream "step-down" voltage regulator 9 regulates the voltage to one for the microcontroller 3 and for the HF module 4 required operating voltage of 5 volts and charges a capacitor 8th on.

After provision of the operating voltage leads the microcontroller 3 Perform a hardware reset and restart the program.

The from the piezo converter 1 generated positive pulse is simultaneously a voltage limit, consisting of the series resistor 6 and the diode 7 the input IN of the microcontroller 3 fed. Through the diode 7 it is possible to recognize the on / off status, since at a positive pulse (pressing the actuator) at the input IN an H level is applied; with a negative pulse (release of the actuator) is at the input IN L level.

The microcontroller 3 in the program sequence queries the level at input IN.

This is the microcontroller 3 the transmission telegram consisting of identifier and the on or off information via the output OUT to the RF module 4 further.

The RF module 4 modulates the transmission telegram with an intended ASK modulation and transmits it by means of an antenna 5 out.

At the Let go of the actuator the above-described processes analog.

• • Initialisierung von Ein- und Ausgang, sowie des Reset-Pins;
• • Pegelabfrage des Eingangs IN;
• • Generierung des Sendetelegramms, bestehend aus einem im Datenspeicher abgelegten 32 Bit Identifier und dem Ein-/Ausschalt-Status;
• • Ausgabe des Sendetelegramms an das HF-Modul 4, inklusive einer zweimaligen Wiederholung.

The program of the microcontroller 3 must contain the following program execution points:

• • Initialization of input and output, as well as the reset pin;
• • Level query of input IN;
• • Generation of the send telegram, consisting of a 32-bit identifier stored in the data memory and the on / off status;
• • Output of the send telegram to the HF-Mo dul 4 , including a two-time repetition.

The design of the antenna 5 could be done directly as a circuit on the board, which gives the opportunity to save costs and space.

1

energy converters

2

DC converter

3

processor

4

RF module

5

antenna

6

dropping resistor

7

Zener diode

8th

capacitor

9

voltage regulators

10

rectifier

Claims (3)

Line-free energy self-sufficient switching element with a radio transmitter module, which preferably operates in an ISM frequency band, the energy required is preferably provided by a piezo-energy converter, the generated by an operation, actuation (direction) dependent voltage pulse fed to a known voltage converter and a DC voltage which is used to supply a microcontroller and the transmission module, characterized in that in the housing of the switching element with an actuating element in the unit an energy converter, an evaluation circuit and a microcontroller are arranged, wherein the microcontroller ( 3 ) is equipped with only one reset pin and at least one data memory and has only one input and one output. Line-free energy self-sufficient switching element according to claim 1, characterized in that the start triggering of the program sequence in the microcontroller ( 3 ) due to the activation of the energy converter ( 1 ) applied operating voltage takes place. Line-free energy-self-sufficient switching element according to claim 1, characterized in that the evaluation circuit for determining the actuating direction of the actuating element, for example / preferably from a series resistor ( 6 ) and a Zener diode ( 7 ), wherein in one switching state, a switch-on signal and in the other switching state a switch-off signal is generated and the input (IN) of the microcontroller ( 3 ) is supplied.