DE102004019600B4 - Bridging device for bridging an electrical load - Google Patents

Abstract

Bridging device (3) for bridging an electrical load (4) with
- A connection means (c, d) for excluding the lock-up device (3) parallel to the electrical load (4) and
An electrical impedance (L1, R2) coupled to the terminal device,
marked by
- A switching power supply (N2, N3, T1), with which the electrical impedance (L1, R2) to the terminal device (c, d) is connected.

Description

The The present invention relates to a lock-up device for bridging a electrical load with a connection device for connecting the lock-up device parallel to the electrical load and an electrical impedance, which is coupled to the connection device.

Various Load types show problems as soon as an upstream switching device, e.g. an installation switch is bridged in the circuit high impedance. This is the case when the switching device at least one additional electrical load element is connected in parallel.

In 1 a corresponding installation execution is shown. The circuit has a mains phase L via an installation switch 1 to a first terminal a of a load 4 connected. At the load 4 it may be, for example, an energy-saving lamp. Weight 4 (Energy saving lamp) is connected with its second terminal b to the N-conductor and thus closes the circuit. The switching device 1 is through a consumer element 2 bridged with high impedance.

Parallel to the load 4 is a bridging device 3 with their terminals c and d at the terminals a, b of the load 4 connected. The bridging device 3 is by closing the switching device 1 switchable to the mains voltage and by opening the switching device 1 separable from the mains voltage. With closed switching device 1 owns the bridging device 3 a high resistance, whereas with the switching device open 1 the bridging device 3 has a low resistance.

In the 1 illustrated energy-saving lamp (load 4 ) comprises a bridge rectifier 41 and a smoothing capacitor 42 , which is parallel to the fluorescent lamp 43 is arranged. In series with the smoothing capacitor 42 and to the fluorescent lamp 43 is a diac 44 arranged upon reaching a certain charging voltage of the smoothing capacitor 42 (about 30 V) the ignition of the fluorescent tube 43 causes.

In this connection, a distinction is made between two types of switching devices 1 , On the one hand, these are conventional installation switches or installation buttons, for which only energy is available for the consumer element when switched off 2 is needed. On the other hand, these are electronic installation switches in two-wire technology, so-called two-wire switches, where the electronics are connected via the connected load 4 is supplied. The two-wire switches are designed so that both in the off and in the on state, the power supply for the consumer element 2 is maintained.

To the consumer elements 2 with which conventional installation switches or installation buttons can be bridged with high resistance, include glow lamps, various display elements (such as light-emitting diodes), power supplies with low-power transformer, power supply switching power supplies as well as capacitor power supplies and resistor power supplies. Such components may also be integrated in two-wire switches.

loads which due to the high-impedance bridging of the Switching device are at risk by means of a consumer element, for example Energy-saving lamps, fluorescent lamps with classic ballast, fluorescent lamps with electronic ballast and low-voltage halogen lamps with certain electronic transformers (e.g. non-dimmable types) and staircase lighting time switch (control input) or be remote switch.

The energy-saving lamps can be designed as warm start lamps or as cold start lamps. All energy-saving lamps available on the market today have a bridge rectifier 41 (see. 1 ) with smoothing capacitor 42 at the entrance. During operation, short current recharging pulses of about 2 ms occur in the time domain of the maximum of each sine half-wave of the mains voltage. The energy-saving lamps ignite upon reaching a certain charging voltage of the smoothing capacitor (about 30 V). The cold start lamps ignite immediately, whereas in the warm start lamps, the filaments are first heated and then shortly thereafter the lamp ignition takes place. In the switched-off state of the high-resistance bridged switching device, however, the smoothing capacitor charges in the energy-saving lamp. At a certain voltage level (about 30 V), a detonation attempt begins. Cold start lamps ignite briefly (flare), thereby the voltage at the smoothing capacitor breaks down again. After some time, the smoothing capacitor recharges to the ignition voltage and the event repeats. The time constant is predetermined by the size of the smoothing capacitor in the energy-saving lamp and the volume resistance of the load element.

Warm start lamps would be due to the delayed lamp ignition in principle to operate on a high-impedance bridged switching device without further action, but this mode is not favored by the lamp manufacturers, since the coil are heated in a predetermined by the charging cycle of the smoothing capacitor rhythm again and again. Premature aging of the warm start lamp would be the result. In the "Technical Primer for Energy Saving Lamps" by OS RAM is therefore considered to be inadmissible on page 30 for operation of warm start lamps on (even high resistance) bridged switching devices.

fluorescent lamps with classic ballast by means of a starter (glow starter, glow starter, electronic starter and others). When switched off, it works practically only the starter resistor. Glimmerstarter and some electronic Starters are relatively high impedance, so when switched off the switching device of the current flow through the consumer element ignition attempts can initiate. The fluorescent lamp flashes briefly, can but not permanently light due to the limited current flow and goes out again.

Parallel compensated fluorescent lamps have a capacitor in parallel set that one enough low impedance forms, so that the voltage drop is insufficient to put the starter into function. Parallel compensation is however less common. Many lamp bases are prepared in such a way that by pulling off a shorting plug and use of a corresponding capacitor automatically a series compensation is created.

at Fluorescent lamps with electronic ballast arise with high impedance bridged switching devices Problems with the reset at the moment of switching on (power on reset). Modern fluorescent lamps with electronic ballast switch namely defective or aged tubes away, a constant To prevent flicker and remain in this state until a power on reset appears.

fluorescent lamps with electronic ballast Today's design have a bridge rectifier with smoothing capacitor at the entrance. The power on reset will only appear if on the smoothing capacitor almost no voltage is applied. When replacing a defective tube must Therefore, before switching on the voltage at the entrance almost completely gone be. However, in the off state of a high-impedance bridged switch-on the voltage at the smoothing capacitor can not go to zero to bring it below the power at reset threshold To reach the fluorescent lamp with electronic ballast with the replaced new fluorescent tube no longer start.

in the In contrast, electronic transformers for low-voltage halogen lights start new because of the dimmer requirement in every half wave and have that the aforementioned problem is not. The mains voltage is also here rectified, but lacks a smoothing capacitor, so that the mains half-waves with higher Frequency are "chopped". The same applies to electronic ballasts that based on this technique, e.g. Concepts with power factor correction (cos φ correction), in which the Power factor is corrected to one.

Farther There are electronic ballasts with a reset button that also do not have this problem.

at Staircase time switches are timed by installation buttons triggered. Conventional installation buttons are usually used for orientation equipped with glow lamps. Furthermore you can also energy-saving sensor devices be used in two-wire technology with push-button function (e.g. Motion detector or similar). If the installation button is in its rest position (switch position "OFF"), then only one flows certain low quiescent current. However, the quiescent current increases too much on, e.g. by connecting in parallel with too many glow lamps or of to many control devices, then could the staircase lighting time switch this current flow as a control signal values and constantly switch on or block its time function.

Around to eliminate the aforementioned problems, parallel to the load (energy saving lamp, Fluorescent lamp, staircase lighting timer) a bridging device arranged. The bridging device takes over in the off state of the switching device (switching device opened) the larger part the current flow, so that the voltage drop across the load as possible is kept low. Is the switching device in the switched on Condition (switching device closed), then the lock-up device however, can carry the full mains voltage, with one possible low energy consumption is desired.

Out The prior art discloses various bridging devices.

So can e.g. a light bulb as a bridging device serve. For most applications this application is u.a. because of the extra Energy consumption disadvantageous.

As a bridging device a capacitor can also be used. This is however through the required high dielectric strength (mains voltage) relatively large volume. If the consumer element requires a relatively large amount of power, the Capacitor have a relatively high capacitance value. The capacitor should then either oversized be adapted to each individual application.

Furthermore, it is known, a low-power transformer in the loaded state as over bridging device to use. Due to the relatively high energy consumption and the relatively large volume of construction small power transformers are unusable for most cases (a version for 230 V in the minimum size of the iron core is very high impedance in the primary circuit).

Further Is it possible, PTC thermistor (PTC Positive Temperature Coefficient) as a bridging device use. In the on state of the switching device is the PTC thermistor is operated at full mains voltage and heats up accordingly, resulting in a corresponding energy consumption. After switching off the switching device, the PTC thermistor is up handy for its cooling ineffective, so after each switching off the switching device for the Duration of the cooling time the aforementioned problems occur.

All have known bridging devices a steady (continuous) transition between the low and the high resistance of their internal resistance.

From the publication DE 43 43 219 C1 is a staircase lighting time switch with integrated bypass module known to which several installation button with glow lamps can be connected. Depending on the level of the applied voltage at the bypass module, it becomes low-resistance or high-resistance. The bypass module has a bridge rectifier circuit whose DC output is connected to an electronic bistable circuit.

Out the book Tietze U., Schenk. Ch .: "semiconductor circuit technology", ISBN 3-540-19475-4, Springer-Verlag Berlin, Heidelberg, New York; 9th edition, 1991, pages 560-565 power Supplies known with linear series regulators. The losses in the series regulator can be greatly reduced by continuously controlled transistors be replaced by switches, whereby switching power supplies or Switching power supplies arise. When the operated switching regulator on the secondary side of the power transformer is called, the power supplies also as secondary clocked Switch mode power supplies, otherwise as primary switched mode power supplies.

The further publication US 4,677,367 A describes a powered boost converter. With such a voltage regulator larger output voltages can be provided than the applied input voltage. There is provided a DC power supply having a high impedance source and such a boost converter.

Furthermore, the document describes US 2003/0090253 A1 a switching power supply with pulse width modulation and low noise sensitivity. The power supply has approximately a constant output voltage and a constant output current. The regulator used comprises a control input which receives a current which corresponds to the sum of the consumption current of the regulator and a feedback current.

task The present invention is therefore the field of application of a high impedance bridged installation switch to expand.

According to the invention this Task solved by a lock-up device to bridge one electrical load with a connection device for excluding the lock-up device parallel to the electrical load and an electrical impedance, which is coupled to the connection device, as well as a switching power supply, with the electrical impedance switched to the connection device is.

With the bridging device according to the invention is it thus possible operate various load types of the installation technology even then, when the installation switch in the circuit is bridged with high resistance. In particular, you can on high-impedance bridged switches thus energy-saving lamps, fluorescent lamps with classic ballast, fluorescent lamps with electronic ballast, Low-voltage halogen lamps with certain electronic transformers (e.g., non-dimmable types), Staircase time switch operated with control input and the like become. This can be conventional Installation switch or installation button with glow lamps, various display elements, a power supply with low-power transformer, a switching power supply for Mains voltage, a capacitor power supply, a resistor power supply and the like are bridged as a high-impedance consumer element. These components can also be integrated in electronic two-wire switches.

Preferably is the switching power supply of the lock-up device according to the present invention in his function interruptible. This is an operation in the so-called Burst-Mode possible.

The Switching power supply can about it In addition, a free-running oscillator, a driver and a switching transistor include. Thus, you can standard market Components for the switching power supply can be used.

The Electrical impedance can be an inductance and an ohmic resistance exhibit. By doing so leaves the power requirement of the parallel to the switch load element take exactly into account.

Of Further, between the connection device and the switching power supply including a two-way rectifier be connected with electrical impedance. Thereby becomes the circuit of the lock-up device polarity independent.

to Control of the switching power supply may further include a voltage sensor for the Detecting the voltage at the terminal device and a so be used connected optocoupler. This ensures that the switching power supply is not working constantly and thus an energy saving can be achieved.

In a particular embodiment has the lock-up device according to the invention a Control device on, with a voltage at the electrical Impedance tapped and dependent This voltage is the switching power supply driving bar. Thus can be to increase the energy input to the consumer.

Advantageous about that In addition, even if the switching power supply including a Constant voltage source for the switching power supply are integrated in one chip. This can be done a simplified version the circuit of the lock-up device to reach.

The The present invention will now be described in detail with reference to the accompanying drawings, in which: show:

1 a basic circuit in which a bypass module is connected in parallel with a load and

2 a diagram of a bridging module according to the invention.

The below described embodiment represents a preferred embodiment of present invention.

• – bei niedriger Strombelastung (Schalter AUS und Last bzw. Lampe AUS) möglichst niederohmig, um alle möglichen Typen von Verbraucherelementen 2 (vgl. 1) mit Strom zu versorgen, ohne dass die oben genannten Probleme auftreten können;
• – Parallelschaltung mehrerer Verbraucherelemente 2 ermöglichen, ohne dass die oben genannten Probleme auftreten können;
• – gemischte Parallelschaltung von verschiedenartigen Verbraucherelementen 2 ermöglichen, ohne dass die oben genannten Probleme auftreten können;
• – bei voller Netzspannung (Schalter EIN und Lampe EIN) möglichst hochohmig, um den Eigenenergieverbrauch gering zu halten;
• – Polaritäts-unabhängige Anwendung (Vereinfachung der Installation im Falle von Verbraucherelementen 2 mit Einweggleichrichtung);
• – Schutz bei Netzunterspannung;
• – Schutz gegen extrem überhöhte Temperatur in der Schaltung (Brandgefahr);
• – geringst mögliches Bauvolumen, flache Bauweise;
• – kostengünstig in der Herstellung.

For a universal use in the installation technology, a bridging module should have the following distinct characteristics:

• - At low current load (switch OFF and load or lamp OFF) as low as possible to all possible types of consumer elements 2 (see. 1 ) with electricity without the above-mentioned problems can occur;
• - Parallel connection of several consumer elements 2 without the above problems occurring;
• - Mixed parallel connection of various consumer elements 2 without the above problems occurring;
• - at full line voltage (switch ON and lamp ON) as high as possible to keep the own energy consumption low;
• - Polarity-independent application (simplification of installation in case of consumer elements 2 with half-wave rectification);
• - protection at mains undervoltage;
• - protection against extremely high temperature in the circuit (fire hazard);
• - lowest possible construction volume, flat design;
• - cost-effective to manufacture.

For this reason, according to the invention, a bridging module in the form of a switched-mode power supply with a wide-range input voltage (AC / DC converter) with a connected base load on the secondary side is proposed. The input voltage range should cover an extended range of 30 to 253 V AC. Preferably, the switching power supply is designed for a functional operation in the so-called burst mode, which means that its function can be interrupted if necessary. In this concept, the function interruption always takes place when the bridging module is at full mains voltage, ie when the switch 1 and the load 4 are turned on (see. 1 ). To control a voltage sensor is needed. Regarding the energy balance appears in this to the base load of the switching power supply no longer, resulting in energy savings.

A circuit diagram of the preferred bypass device is shown in FIG 2 shown. The terminals c, d of the bypass module become compliant 1 parallel to the load 4 connected. When the switch 1 is turned off, the voltage applied to the terminals c, d voltage is passed through the fuse F1 to the bridge rectifier V1, rectified and applied to the capacitor C1. The capacitor C1 charges.

From a certain voltage on the input terminals c, d (preferably about 35V AC) is the constant voltage source N1, which is connected to an output terminal of the bridge rectifier V1, active and the switching network starts. This consists of a series circuit of a free-running oscillator N2, a driver N3 and a switching transistor T1, preferably a MOSFET. The drain contact D of the switching transistor T1 is also connected to the output terminal of the bridge rectifier V1, to which the constant voltage source N1 is also connected. The source contact S of the switching transistor T1 is connected to a series circuit of a coil or inductor L1 and a load resistor R2. Parallel to the series connection is a flyback diode V3. The source contact S of the switching transistor T1 is connected via a capacitor C2 to the input of the freewheel connected to oscillator N2. As soon as the transistor T1 turns on, the inductance L1 is magnetically charged by the current through the load resistor R2. After turning off the transistor T1, the voltage at the inductance L1 reverses, the flyback diode V3 becomes conductive and the energy from L1 is discharged through the load resistor. In this case, N2 ensures a pulse-pause ratio adapted to the circuit in a known manner: short switch-on pulses with longer switch-off times for T1 alternate periodically, the length of the switch-on pulses being made dependent on the voltage at C1. The higher the voltage across the capacitor C1, the shorter the charging pulses for L1. Through the consumer element 2 creates a current flow to supply its electronics. The load through the bridging module must be adjusted here, ie the higher the power consumption of the consumer element 2 is, the smaller the load resistor R2 has to be 2 to get voted.

When the switch 1 is closed, the full mains voltage of 230VAC is at the terminals c, d of the bypass module. For the higher voltage, a zener diode V2 becomes conductive (voltage sensor), so that an optocoupler U1 becomes active. For this purpose, a series circuit consisting of an ohmic resistor R1, the Zener diode V2 and the light-emitting diode of the optocoupler U1 is connected to the output terminals of the bridge rectifier V1. As a result, the transistor of the opto-coupler U1 becomes conductive and blocks the driver N3. The switching power supply is turned off and no current flows through the load resistor R2. In this way energy is saved.

The Circuit of the bypass module is through the bridge rectifier V1 (full wave rectifier) polarity independent. Because there are two-wire electronic switches there for that the supply of the own electronics use a half-wave rectification, this is a decisive advantage for the installation of an installation.

In an alternative embodiment There is no voltage sensor and optocoupler for shutdown. In this case, the full load is always at R2. The switching power supply works constantly at high and low voltage at terminals c, d and consumes energy.

In another embodiment, a control loop may be provided with the energy requirement at the load resistor R2. In this case, the voltage at R2 must be smoothed by paralleling a capacitor. A voltage detector monitors the voltage across this capacitor and controls the blocking input of the driver N3, usually also via an optocoupler. As a result, the energy supply or the current through the consumer 2 be graded finer. Since the switching power supply operates at high voltages at the terminals, but results in the same energy loss at R2 as in 2 , given by the consumer 2 required electricity.

Another embodiment may consist in that the components of the switching power supply including the constant voltage source N1 in a chip N4 (see. 2 ) are integrated. An example of this is the module TNY 253 from the company "power integration", which simplifies the design of the circuit.

Furthermore is an execution the circuit completely in SMD assembly possible. she needed lowest volume in a flat design.

Claims (8)

Bridging device ( 3 ) for bridging an electrical load ( 4 ) with - a connection device (c, d) for excluding the lock-up device ( 3 ) parallel to the electrical load ( 4 ) and - an electrical impedance (L1, R2), which is coupled to the connection device, characterized by - a switching power supply (N2, N3, T1), with which the electrical impedance (L1, R2) to the connection device (c, d) is switched. bridging device according to claim 1, wherein the switching power supply (N2, N3, T1) in its Function is interruptible. bridging device according to claim 1 or 2, wherein the switching power supply (N2, N3, T1) has a free-running Oscillator (N2), a driver (N3) and a switching transistor (T1) includes. bridging device according to one of the preceding claims, wherein the electrical impedance (L1, R2) an inductance (L1) and an ohmic resistance (R2). bridging device according to one of the preceding claims, wherein between the connection device and the switching power supply (N2, N3, T1) together with electrical impedance (L1, R2) a two-way rectifier (V1) is connected. bridging device according to one of the preceding claims, wherein for controlling the Switching power supply (N2, N3, T1), a voltage sensor (V2) for detecting the voltage to the terminal device and an associated Optocouplers (U1) are used. bridging device according to one of the preceding claims with a control device, with the voltage at the electrical impedance (L1, R2) can be tapped and depending this voltage, the switching power supply (N2, N3, T1) can be controlled. bridging device according to one of the preceding claims, wherein the switching power supply Including (N2, N3, T1) a constant voltage source (N1) for the switching power supply in one Chip (N4) are integrated.