DE102012200722A1 - Device and method for determining a successful contacting of a connection - Google Patents

Abstract

A device and a method for determining a contact making of a connection or socket (21, 25) are proposed, comprising at least one voltage divider (17), means for detecting the voltage (U) at the voltage divider (17), means (16) for evaluating the time profile of the voltage (U), characterized in that each connection or each socket (21, 25) at least one capacitor (31, 35) is connected in parallel, wherein for detecting a successful contacting of a terminal or a socket (21, 25) the means for evaluating the voltage (U) detect a time constant (τ), with which the voltage (U) after deactivating the terminals or socket (21, 25) drops.

Description

State of the art

The invention is based on a device and a method for determining a successful contacting of a connector according to the preamble of the independent claims. From the DE 10 2009 045 756 A1 Already a method and a device for controlling the authorization of charging of electrically operated vehicles out. Here, a control unit between a main terminal and a plurality of charging sockets is provided, which are connected via a power line to the control unit. A vehicle to be charged is connected to one of the charging sockets and the total charging current is detected, which is passed from the main terminal via the control unit to the charging sockets. From the DE 101 04 905 A1 a socket monitoring device is already known. The socket has at least one switching means which can be actuated by a plug inserted and at least one display means switches to indicate the proper fit of the plug in the socket.

The invention has for its object to check the number of contacted sockets or connections without a manual operation in a particularly simple manner. In this case, the device should not be removed even in later operation of the battery power. This object is solved by the features of the independent claims.

Advantages of the invention

The device according to the invention and the method according to the invention for determining a contacting of a terminal according to the features of the independent claims have the advantage that by integrating a capacitor at each outlet or terminal in a successful contacting based on the measured total capacity on the number contacted Sockets can be deduced. The use of capacitors allows the quiescent current freedom of the entire system. Particularly advantageous in this type of determination of the contact is that no high absolute accuracy of the voltage measurement is required, since only the ratio of the voltages is included in the calculation. Now, if a capacitor is integrated per outlet, results in a different steep drop when switching off the voltage, depending on how many sockets or connections are connected.

In an expedient development, a voltage divider is provided, which is dimensioned in the order of 10 kΩ / 47 kΩ and 1 μF per socket. This results in a time constant τ of 57 ms per capacitor. This time constant can be by measuring the voltage for a short time, for example, 100 ms, after switching off the switching means and the required time until this voltage on 1 / e (36.8%) has subsided.

In an expedient development it is provided that the voltage divider can be switched off via a switching means. As a result, a particularly low quiescent current consumption of a control device can be achieved.

Further expedient developments emerge from further dependent claims and from the description.

drawing

An embodiment of the device according to the invention and of the method according to the invention for determining a successful contacting of a connection is shown in the drawing and will be described in more detail below.

Show it:

the 1 a circuit diagram of the device according to the invention and

the 2 three time-dependent curves of the voltage U for n = 3 and n = 5 with associated switch position of the first switching means.

Via a supply connection 30 (so-called clamp 30 ) will have multiple connections 21 or sockets fed up to n connections 25 or n sockets 25 , These connections 25 are in parallel with the supply connection 30 electrically conductive contacted. The second contact of the outlet 21 . 25 is interconnected to ground. Parallel to the first connection 21 or the first outlet is a first capacitor 31 switched to ground. Opposite the nth connection 25 or the nth socket is an nth capacitor 35 also connected to ground. The supply connection 30 settles with the sockets 21 . 25 via a first switching means 10 connect electrically conductive. After the first switching means 10 is a voltage divider 17 interconnected to ground. The voltage divider 17 consists of a first resistor 18 and a second resistor 20 , The potential between the two resistors 18 . 20 is tapped by a converter 14 , preferably an analog-to-digital converter (AD converter), which is part of a microprocessor 16 can be.

Supply of sockets 21 . 25 is guided via the common switching means 10. This first switching means 10 is usually a relay, but can also be designed as a semiconductor switch. The output voltage after the first switching means 10 is over the voltage divider 17 the AD converter 14 which is usually in a microcontroller 16 integrated, supplied. This voltage divider 17 is preferably via a second switching means 12 can be switched off in order to achieve possibly the lowest possible quiescent current consumption of the control unit. According to the invention is now for every outlet 21 . 25 or connecting a capacitor 31 . 35 provided, in each case the supply connection of the socket 21 . 25 is connected in parallel with ground. Depending on how many connections 21 . 25 or sockets 21 . 25 correctly electrically conductive with the supply connection 30 are contacted, there is a certain total capacity of the arrangement, consisting of those capacitors 31 . 35 whose connections 21 . 25 or sockets are contacted in a correct manner electrically. The microcontroller 16 evaluate now based on the voltage at the voltage divider 17 from how high the total capacity of the arrangement is. To do this, convert the AD converter 14 the detected voltage U at the voltage divider 17 for the corresponding digital evaluation in the microcontroller 16 ,

The measurement is started at time t0 when the first switching means 10 is opened like the lower diagram in 2 can be seen. Then the voltage curve U at the voltage divider 17 detected. Due to the capacitive behavior of the capacitors 31 to 35 the tension decays in the course of the e-function. The characteristic decay constant τ depends on the total capacity of the arrangement. This characteristic time constant τ is now determined by the microcontroller 16 , For this purpose, the corresponding time is detected at which the voltage on 1 / e (36.8%) has subsided. The number of n sockets 21 . 25 then results from the time determined to reach the said 36.8%. If there is a deviation from the expected time constant, this indicates that not all connections 21 . 25 or sockets were contacted electrically conductive. Corresponding countermeasures or display means can be activated. As an example, in the upper diagram of the 2 the time course of the voltage U for n = 3 contacted terminals 25 or in the middle diagram of the 2 the time course of the voltage U for n = 5 contacted terminals 25 ,

Especially useful is the voltage divider 17 for example, so dimensioned that the first resistance 18 for example, about 10 kΩ and the second resistor 20 47 kΩ. As capacity of the capacitors 31 . 35 in this case 1 μF is selected. This results in a time constant τ of 57 ms per capacitor 31 . 35 , If there are n capacitors, the time constant τ has the n-fold value of 57 ms. From this it is easy to determine how many connections 21 . 25 actually contacted.

Especially in motor vehicles are often sockets 21 . 25 installed, so that the device and the method are just this. Examples of corresponding sockets 21 . 25 are connections for laptop, MP3 player, mini-refrigerators, etc. In order to make all sockets in the manufacture of the vehicle 21 . 25 To verify, the applied voltage is measured at each in the usual manner according to the prior art. The now presented device and method allow the number of sockets contacted 21 . 25 without checking a manual operation. This can also be done in later operation so that the battery of the vehicle no power is removed.

There are other alternatives possible. In particular, the second switching means 12 over which the voltage divider 17 can be switched off, not required. However, it serves to minimize the power consumption of the controller with the corresponding microcontroller 16 to reach. Also the dimensioning of the resistors 18 . 20 or the capacitors 31 . 35 can be done to achieve the desired time constant or voltage levels in the appropriate manner. It is also possible, instead of the analog-to-digital converter 14 to replace a comparator with appropriate threshold detection.

In 2 is a common voltage curve U of the voltage at the voltage divider 17 shown. This voltage is the AD converter 14 fed and accordingly from the microcontroller 16 evaluated. At the beginning is the first switching means 10 closed, which is marked with a logical 1. At time t ₁ , the first switching means 10 open. The at the power supply 30 connected sockets 21 . 25 each with parallel capacitors 31 . 35 behave like an RC element. Thus, the voltage U decreases in the form of an e-function with a certain time constant τ _n . n denotes the number of contacted sockets 21 . 25 , In the uppermost example, the voltage U drops relatively quickly. The corresponding time constant τ at n = 3 for only three contacted sockets 21 . 25 is determined so that the microcontroller 16 detects the period of time that elapses beginning with the time t0 until the voltage U has dropped to 36% of the initial value U ₀ . With the above dimensioning of τ = 57 ms, the microcontroller would now be used 16 capture a time of 3 times 57 ms. Knowing the known time constant τ = 57 ms, the microcontroller now recognizes 16 that only three sockets are contacted. According to the mean time representation of the voltage U at the voltage divider 17 the voltage U decreases with a larger time constant τ, ie slower than in the first example. Again, the microcontroller determines 16 the time interval between t0 and the drop of the voltage U to 36% of the output value U = U ₀ . In the example this would be 5 times 57 ms at n = 5 contacted sockets 21 to 25 , The microcontroller 16 now compares the determined time constant τ, divides it by the time constant τ = 57 ms per capacitor and thus receives approximately the number of used or contacted sockets 21 to 25 , By comparison with the proper number of contacted sockets the microcontroller recognizes 16 , whether a faulty operating state exists. This could also be done directly by comparing the measured time constant τ with the expected time constant τ at, for example, five sockets to be properly contacted 21 to 25 respectively.

Particularly advantageous in the described type of measurement is that no high absolute accuracy of the voltage measurement U is required because only the ratio of the voltages across the resistors 18 . 20 is included in the calculation for determining the time constant τ.

Device and method are particularly suitable for determining the proper contacting of the terminals or sockets in a motor vehicle. However, the use is not limited to this.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009045756 A1 [0001]
• DE 10104905 A1 [0001]

Claims (8)

Device for determining a successful contacting of a connection, in particular a socket ( 21 . 25 ), comprising at least one voltage divider ( 17 ), Detection means ( 14 ) of the voltage (U) at the voltage divider ( 17 ), Evaluation means ( 16 ) of the time course of the voltage (U), characterized in that each connection or each outlet ( 21 . 25 ) at least one capacitor ( 31 . 35 ) is connected in parallel, wherein for detecting a successful contacting a terminal or a socket ( 21 . 25 ) the evaluation means ( 16 ) detect a time constant (τ) of the voltage (U), with which the voltage (U) after activating or deactivating the supply of the connections or socket ( 21 . 25 ) to change. Apparatus according to claim 1, characterized in that the evaluation means ( 16 ) comprise a time measurement for measuring the time constant (τ), which elapses when, starting from a certain starting time (t ₁ ), the voltage (U) changes by a certain percentage. Device according to one of the preceding claims, characterized in that the capacitor ( 31 . 35 ) in its capacity identical to the other parallel to the other terminals or sockets ( 21 . 25 ) interconnected capacitors ( 31 . 35 ) is selected. Device according to one of the preceding claims, characterized in that the voltage (U) via an analog-to-digital converter ( 14 ) a microcontroller ( 16 ), which serves as an evaluation means. Device according to one of the preceding claims, characterized in that the voltage divider ( 17 ) at least two resistors ( 18 . 20 ). Device according to one of the preceding claims, characterized in that the ratio of the resistances ( 18 . 20 ) is about 1: 4.7. Device according to one of the preceding claims, characterized in that the capacitance of the capacitor ( 31 . 35 ) is about 1 μF. Method for determining a successful contacting of a connection or socket ( 21 . 25 ), with each connection or socket ( 21 . 25 ) at least one capacitor ( 31 . 35 ) is connected in parallel, comprising the following steps: activating or deactivating the connections or sockets ( 21 . 25 ), - detecting a course of a voltage (U) after activating or deactivating the supply ( 30 ), wherein the course of the voltage (U) by a voltage divider ( 17 ) and the interconnected capacitors ( 31 . 35 ) is detected as an RC element, - detecting the time at which the voltage (U) changes by a certain percentage or by a certain amount, - determining the corresponding time period (τ) at which the voltage is the corresponding percentage or amount has changed, - comparing this period of time (τ) with an expected period of time as a reference value for the properly made number of contacts.

Images