FR2819890A1 - LAMP TEST CIRCUIT - Google Patents

Abstract

Lamp test circuit for at least one lighting element (H1, H2, H3) which operates with alternating voltage and is associated with a user device (K1, K2, K3) and which comprises a test current channel (10 ) can be switched via a test button (Sb), for the lighting element, and an element (C1, C2, C3) located in the test current channel to reduce the return supply by voltage, characterized in that a capacitor (C1, C2, C3) is located in a current path which is parallel to the lighting element (H1, H2, H3), in that an alternating current light-emitting diode element is used as a lighting element (H1, H2, H3), and in that when the test button (Sb) is pressed the parallel current channel is open and the capacitor (C1, C2, C3 ) is connected in the test current channel (10).

Description

LAMP TEST CIRCUIT

  The present invention relates to a lamp test circuit for at least one lighting element which operates with alternating voltage and is associated with a user device and which comprises a test current channel which can be switched via '' a test button, for the lighting element, and an element located in the test current channel to reduce

  return voltage supply.

  A lamp test circuit for at least one element

  Illumination comprising a current path which can be switched by means of a test key and passing through an illumination element and a diode situated in the current path to prevent a voltage feedback is indicated in the Schaltgerate catalog- Katalog fur Niederspannungs-Schalttechnik de Siemens NS K 1999/2000

(page 9/109).

  In AC networks, this circuit is only suitable for incandescent lamps or for fluorescent lamps as lighting elements, and also only under certain conditions. Fluorescent lamps work in the case of testing of lighting devices by means of diodes with only alternating alternating current and therefore only light with reduced brightness, and therefore the possibility of identification

visual is weak.

  For the testing of alternating current LED diode elements which have a capacitor as a capacitive drop resistor, this lamp test circuit is absolutely unsuitable since the capacitor is charged via the diode of the lamp test circuit below the peak value of the alternating voltage and then no current can flow anymore. This means that the alternating current LED diode element only lights up once briefly

and then turns off.

  The invention therefore aims to provide a lamp test circuit for LED diode elements with

alternating current.

  The problem is solved in accordance with the invention from the test circuit for lamps of the type indicated above by the fact that a capacitor is located in a current path which is parallel to the lighting element, that a alternating current light emitting diode element is used as the lighting element, and when the test button is pressed the parallel current channel is opened and the capacitor is connected in

the test current channel.

  According to another characteristic of the invention, the capacitor is integrated in the base of the diode

luminescent alternating current.

  According to another characteristic of the invention, the lighting elements are associated with the operating devices by means of contacts of

contactor switching.

  According to another characteristic of the invention, at least one resistor is connected in series with the

  capacitor to provide protection against over-

  tensions. According to another characteristic of the invention, a varistor is also connected in parallel with the

capacitor.

  According to another characteristic of the invention, the lighting elements are arranged in a table of

control of a control circuit.

  The essence of the invention lies in the fact

  that a capacitor is associated with each user device

  tion and is located in a current path parallel to an alternating light emitting diode element and that, when the test button is pressed, the parallel current path is open and the capacitor located in the current path test is connected. The alternating current light emitting diode element receives half of the mains voltage and lights sufficiently brightly to allow visual inspection. When one of the luminescent elements is already connected, since the associated operating device is already connected to the network - via a contactor - the actuation of the test key has no influence on this luminescent element. Due to the miniaturization of electronic components, it is also possible to integrate the capacitor in the base of the light-emitting diode.

alternating current.

  In general, the lighting elements are not associated directly in the circuit of the user devices, but they are associated with the user devices via contacts of

contactor switching.

  In order to be certain that overvoltages do not

  not destroy the capacitors, we can plug in sup-

  with one or more additional resistors in series, or additional resistors and a varistor with capacitors. In both cases, the additional resistance connected is adapted to the resistance of the capacitor. Resistors, capacitors and lighting elements can be arranged on flexible conductive paths. An example of the manufacture and arrangement of a structure of conductive tracks produced by hot pressing is given in document DE 199 08 574 Ai. Several resistors can be used when, for rational manufacturing reasons, resistors with a low nominal power are used and the suitable nominal power is obtained only by means of series connection of two or more

two resistances.

  As is also otherwise usual, the lighting elements can be arranged in a control panel of a control circuit. Here we can notice

  advantageously that the control and signal elements

  sation have small dimensions. They only occupy one

  low space in the control panel.

  Light indicators are known, which contain capacitor elements in their base (in the base of the lamp). When the value of the capacitor in the test circuit has the same value as the capacitor in the alternating current LED diode element, the alternating current LED diode elements in the assembly can operate even with a double voltage of

the nominal network voltage.

  Other features and advantages of the pre-

  invention will emerge from the detailed description

  given below taken with reference to the appended drawing, the single figure of which represents an example of a circuit

according to the invention.

  The figure shows a lamp test circuit as proposed in a control unit for three user devices with alternating voltage. In each current channel is connected a lighting element Hl, H2, H3 operating under alternating voltage. Each

  current channel is associated with a user device.

  The switches K1, K2, K3 are contacts separated from

  switching, for example contactors, which are action-

  born when the user devices are connected to the mains voltage. As the lighting element, a light emitting diode is used respectively (such as an alternating current LED diode element), and the voltage level is preferably higher than 110 V. The lighting elements indicate the state respective operation or control of the operating devices, for example

  machines, processes or drives.

  With the lamp test circuit, the control of the operation of all the indicator lights is possible independently of the respective operating or control status of the user devices associated with them. For each lighting element Hl, H2, H3 there

  is provided, in a parallel current channel, a condensa

  tor Cl, C2, C3 which "works without function" from the electrical point of view in normal operation. The actual power loss is negligible. Using the test key Sp, connect the test current channel 10 for all the indicator lights connected to the control unit, and a quick visual check of the lighting elements Hl, H2 can be carried out. H3. The wiring of the test button Sp is carried out in the form of a change-over switch

  (closing contact - opening contact combination).

  The capacitors are located respectively in the terminal xl of the lighting element. The second capacitor terminal is connected via the opening contact of the test button Sp to the neutral conductor of the

alternating current network.

  When the test button is pressed,

  each capacitor is removed from the parallel current path

  It is connected to the test current channel in series with the lighting element Hl, H2, H3. The elements with alternating current light-emitting diodes receive for example half of the tension of the network and light with a sufficient luminosity. When a warning lamp has already been connected via the switching contact of one of the contactors K1, K2, K3, actuation of the test button Sp has no influence on this warning lamp.

Claims (6)

  1. Lamp test circuit for at least one lighting element (H1, H2, H3) which operates with an alternating voltage and is associated with a device for use (K1, K2, K3) and which comprises a test current (10) which can be switched via a test button (Sb), for the lighting element, and an element (Cl, C2, C3) located in the test current channel for reduce the return voltage supply, characterized in that a capacitor (C1, C2, C3) is located in a current path which is parallel to the lighting element (H1, H2, H3), in that that an alternating current light-emitting diode element is used as an illumination element (H1, H2, H3), and that when the test button (Sb) is pressed the parallel current channel is open and the capacitor (C1, C2, C3) is   connected in the test current channel (10).   2. Lamp test circuit according to the claim   tion 1, characterized in that the capacitor (C1, C2, C3)   is integrated in the base of the light emitting diode with alternative rant (H1, H2, H3).   3. Lamp test circuit according to claim 1 or 2, characterized in that the lighting elements (H1, H2, H3) are associated, by means of switching contacts (K1, K2, K3) of contactors , to the operating devices.   4. Lamp test circuit according to one   conch of claims 1 to 3, characterized in that at   less resistance is connected in series with the condenser   sator (C1, C2, C3) to provide protection against overvoltages.   5. Lamp test circuit according to the claim   tion 4, characterized in that in addition a varistor is   connected in parallel with the capacitor (Cl, C2, C3).   6. Lamp test circuit according to any one   claims 1 to 5, characterized in that the   lighting elements (H1, H2, H3) are arranged in a   control panel of a control circuit.