EP1775366A1 - Control circuit for fabric treatment devices - Google Patents

Abstract

Circuit for controlling a laundry treatment appliance comprises a motor circuit (20) with an alternating current motor and a door locking circuit (30), both circuits being controlled by a single electronic switch (41).

Description

The invention relates to a control of a device for laundry treatment according to the preamble of claim 1.

Previously used circuits for controlling a laundry treating appliance, such as a washing machine or a spin dryer, include a motor circuit and a door latching circuit, both of which are to be controlled separately. The motor circuit has one through an AC phase gating with a triac-controlled AC collector motor for driving the washing drum. In the motor circuit relays are still connected by the one hand, the direction of rotation of the motor is reversible and on the other hand can interrupt the motor circuit, as it is necessary for example in case of failure, ie an emergency shutdown. Through the door lock circuit, the loading opening or door of the washing machine or spinner is locked with a switch controlled by a PTC bimetallic element during the entire washing or spinning operation in order to prevent any possible endangering of the user by contact with the rotating drum. This PTC bimetallic element is permanently driven with a separate electronic or electromechanical switching element during the washing process.

Such a circuit for controlling a device for laundry treatment with two independent circuits for engine and door lock may, with appropriate interpretation, violate the provisions of European standard EN 60335-1 §19. In this case, additional circuit will be required to monitor the door lock circuit. In addition, 2 independent circuits require an increased material requirement, which runs counter to the absolute requirement for the household appliance industry, namely the cost savings.

In recognition of these circumstances, the present invention is therefore based on the problem to provide a circuit for controlling a device for laundry treatment, on the one hand meets the need for cost reduction and on the other hand the European regulations for home appliances with rotating drums.

The object is achieved by a circuit for controlling a device for laundry treatment, wherein the circuit comprises a motor circuit with an AC motor and a door lock circuit, wherein the motor circuit and the door lock circuit via a single common electronic switching element can be controlled.

Under a device for laundry treatment is a washing machine, a tumble dryer, a spin dryer, etc. understood. The novel combination of the control of the two in their function and control completely different electrical components of a washing machine, namely the washing motor and the door lock, in a single common switching element is made possible by the use of standard, in any circuit for engine control in a washing machine anyway components. In doing so, certain precisely defined sequences must be observed when controlling the two components.

In other words, a circuit for driving a laundry treating apparatus includes a motor circuit and a door latch circuit, wherein the motor circuit and the motor circuit Door lock circuit are interconnected in such a way that both circuits are jointly controlled via a single common electronic switching element, so are supplied with power. Due to the omission of a separate switching element for the door lock circuit manufacturing costs are saved. In addition, the requirements of the European standard are met in a simple manner.

In an advantageous development of the door lock circuit is switched through when driving on the single common electronic switching element continuously, the motor circuit is interrupted by at least one electromechanical switch at the same time.

By activating the single common switching element of the door lock circuit is driven and switched continuously, so energized. By activating the single common electronic switching element, the motor circuit is simultaneously activated in addition to the door locking circuit. In the motor circuit is at least one electromechanical switch, through which the motor circuit can be interrupted, so it can be switched off.

The arrangement of at least one electromechanical switch in the motor circuit ensures, despite only a single common electronic switching element for the motor circuit and door lock circuit, that the door lock required for safety reasons is activated before the laundry drum is driven by the AC motor.

In a preferred alternative, the single electronic switching element is a triac or a thyristor.

In a further embodiment, the door lock circuit has a switch and / or a mechanism for locking the door, which can be actuated by PTC bimetallic element.

The fact that the door lock circuit has a controllable by a PTC bimetallic element switch and / or a mechanism for locking the door, it is ensured that after switching off the common electronic switching element, ie the power switch circuit of the door lock circuit, the mechanism for locking the door at least another 30 sec remains locked. In other words, even after only a brief energization of the door lock circuit, the locking mechanism remains closed for at least 30 seconds and the door can not be opened. Until the door could be opened, the laundry drum has come to a standstill without any need for an additional electronic component to control it.

Advantageously, two electromechanical switches can be used in the motor circuit, which are connected to the winding of the AC motor rotor or to the winding of the AC motor field and which interrupt the motor circuit in a first switching state and cause a reversal of the direction of rotation of the AC motor in a second switching state.

By changing the switching states, the direction of rotation of the AC motor is reversible. An electromechanical switch is understood to mean relays or comparable components.

Due to the different arrangement options for the two electromechanical switches, it is ensured that constructive variations in the wiring of a device for laundry treatment are possible.

In a further embodiment, the motor circuit in addition to the two electromechanical switches for reversing the direction of rotation of the AC motor and interrupting the motor current to another electro-mechanical switch for field switching, wherein the electromechanical switch is connected to the field switching with the other winding of the AC motor, as the winding, which is connected to the two electromechanical switches for reversing the direction of rotation and interrupting the motor current.

By further electromechanical switch in the motor circuit ensures that advantageously a field switching is possible.

• Fig. 1 eine Schaltung zur Ansteuerung eines Geräts zur Wäschebehandlung gemäß Stand der Technik,
• Fig. 2 ein zeitabhängiges Schaltzustandsdiagramm gemäß Stand der Technik,
• Fig. 3 eine Schaltung zur Ansteuerung eines Geräts zur Wäschebehandlung gemäß vorliegender Erfindung,
• Fig. 4 ein zeitabhängiges Schaltzustandsdiagramm gemäß vorliegender Erfindung.

An embodiment will be explained in more detail with reference to the drawing and the description below. Show it

• 1 shows a circuit for controlling a device for laundry treatment according to the prior art,
• 2 shows a time-dependent switching state diagram according to the prior art,
• 3 shows a circuit for controlling a device for laundry treatment according to the present invention,
• 4 shows a time-dependent switching state diagram according to the present invention.

Figure 1 shows a known circuit 10 for controlling a washing machine with a motor circuit 20 and a door lock circuit 30. The motor circuit 20 has a triac 21, via which the AC washing motor 22 is driven or energized. The switching on and off of the washing motor takes place exclusively via the triac 21. In the present example, the direction of rotation reversibility of the washing motor 22 is realized in that two relays 23.1 and 23.2 are connected to the rotor winding of the washing motor 22.1. An optional further relay 24 for field switching is arranged in the supply line to the field generating winding of the washing motor 22.2. In addition to the possibility of reversing the direction of rotation of the washing motor 22, the relays 23.1 and 23.2 also enable a power-off circuit of the washing motor 22.1. However, the use of this option is not known from the prior art.

The parallel to the motor circuit 20 connected door lock circuit 30 has a separately switchable triac 31 for driving the Door lock circuit 30 on. Via the triac 31, a PTC bimetallic element 32 is energized, which causes the locking of the washing machine door. By locking the washing machine door, a door contact 33 is closed. The door contact 33 is a backup that the washing machine motor 22 starts only in the case and drives the laundry drum when the door is locked against opening and a risk of injury is excluded.

Figure 2 shows the course of the switching state (activated - ON or OFF - OFF) of the components in the motor circuit 20 and the door lock circuit 30 as a function of time. The washing program start is indicated by the first vertical line and the washing program end by the second vertical line. FIGS. 2 a, 2 b and 2 c relate to components in the motor circuit 20, FIGS. 2 d and 2 e refer to components of the door locking circuit 30.

A washing program begins by the triac 31 is activated after a certain time t according to Figure 2d and this remains activated until the end of the washing process. With the end of the washing process, shortly before the end of the watch program, the triac 31 is de-energized, so the bimetallic locking element 32 is no longer energized.

Shortly after activation of the triac 31, the PTC bimetallic element 32 reaches its operating temperature and locks the door lock, as shown in Figure 2e, even beyond the end of the wash until the end of the wash program. Only with the end of the wash program is it again possible to open the washing machine door.

Additional control software for balancing the switching states of the switching elements 21 and 31 ensures that, as shown in Figure 2a, only after the door lock is locked by the PTC bimetal 32, the triac 31 is activated and the motor circuit 20 is energized.

Figure 2b shows that from the activation of the triac 21, the drive of the laundry drum by the washing motor 22 is possible, provided that the relays 23.1 and 23.2 are in such a switching position that the motor 22 is activated (Figure 2c). This is always the case with known circuit solutions of the prior art.

An interruption of the washing motor movement (FIG. 2 b) can be achieved by deactivating the triac 21 (FIG. 2 a). At the end of the washing process, or with the last deactivation of the triac 21 (FIG. 2a) and the washing motor movement (FIG. 2b) ended therewith, the triac 31 can be deactivated at the same time, which, as mentioned after expiration of at least 30 sec Washing program makes opening the washing machine door possible.

FIG. 3 shows a circuit 40, which corresponds to the idea of the present invention, for controlling a washing machine with a motor circuit 20 and a door locking circuit 30, both circuits 20 and 30 being able to be supplied with current via a single common electronic switching element 41, such as a triac.

The basic structure of the motor circuit 20 and the door lock circuit 30 corresponds to the respective structure as has been described for Figure 1. The description of FIG. 1 is therefore referred to. However, for the purpose of reversibility or engine shutdown, it would also be possible to interconnect the two relays 23.1 and 23.2 with the winding of the washing motor 22.2 generating the field. The optional further relay 24 could also be connected to the rotor winding of the washing motor 22.1. For example, an arrangement is also possible in which a relay is used only to reverse the direction of rotation and a relay is used only to interrupt the motor circuit.

The essential difference between circuit 40 and circuit 10 is that in circuit 40, the door latch circuit 30 is behind the single common electronic switching element 41 with the motor circuit 20 is interconnected. As a result, the motor circuit 20 and the door lock circuit 30 can be energized together by activating only one triac 41 and can also be switched off together.

However, the simultaneous energization of motor circuit 20 and door lock circuit 30 is also decoupled. This decoupling is done by using the relays 23.1 and 23.2 and is an outstanding feature of the present invention. Because while the door lock circuit 30 remains active, the washing motor 22 and thus the drive of the laundry drum by means of the relays 23.1 and 23.2 can be switched off. In this case, the washing machine door would remain locked, for example, for safety reasons, although the motor 22 is temporarily switched off.

FIG. 4 shows the course of the switching state (activated-ON or deactivated-OFF) of the components of the circuit 40 according to FIG. 3 in the motor circuit 20 and in the door interlocking circuit 30 as a function of time. The washing program start is indicated by the first vertical line and the washing program end by the second vertical line. FIG. 4a relates to the switching element 41. FIGS. 4b and 4c relate to components in the motor circuit 20. FIG. 4d relates to the door-locking circuit 30.

A washing program begins by the common triac 41 being actuated after a certain time t according to FIG. 4a.

Shortly after activation of the triac 41, the PTC bimetallic element 32 reaches its operating temperature and locks the door lock, as shown in Figure 4d, even beyond the end of the washing process to the end of the wash program. Only now it is again possible to open the washing machine door.

Although the motor circuit 20 is also energized simultaneously with the door locking circuit 30, the drive of the laundry drum by the washing motor 22, as shown in FIG. 4b, does not start until after some time.

As shown in FIG. 4 c, this is due to the fact that initially the relays 23. 1 and 23. 2 must be switched continuously in order to allow a flow of current through the washing motor 22. In other words, via the circuit of the relays 23.1 and 23.2, the energization of the washing motor 22 can be interrupted.

In contrast to the known circuit (Figure 1), the circuit of Figure 3 requires no additional control software that monitors the switching state of two switching elements 21 and 31. Because of the single control 41 both the motor circuit 20 and the PTC bimetallic element 32 are energized in the door lock circuit 30, so that the washing machine door is always securely locked, as long as the control 41 is active.

An interruption of the washing motor movement (FIG. 4b) can be achieved on the one hand by deactivating the triac 41 (FIG. 4a) or on the other hand by interrupting the power supply through the relays 23.1 and 23.2 (FIG. 4c). However, to save the contacts of the relays 23.1 and 23.2, first the motor circuit 20 (together with door lock circuit 30) via the triac 41 de-energized (Figure 4a), switched in this switching state via the relays 23.1 and 23.2 (Figure 4c), the engine condition and then switched on again via the triac 41, the current flow (Figure 4a). Consequently, the "switching spark" at the triac 41, but not at the contacts of the relays 23.1 and 23.2.

Due to the trailing lock by the PTC bimetallic element 32 in the door latch circuit 30, the door latch remains latched until the end of the washing process (FIG. 4d), even though the switching element 41 should be temporarily deactivated during the washing process (FIG. 4a). With the end of the washing process, shortly before the end of the watch program, the triac 41 is permanently de-energized until the trailing lock releases and allows the door to open safely, since the laundry drum has stopped in the meantime.

If the washing motor 22 must remain switched off during the wash program for a long time, can be energized by turning on the triac 41 during the program even when the program is switched off without relays 23.1 and 23.2 motor (Figure 4a).

Claims (6)

A circuit for driving a laundry treatment apparatus, the circuit comprising a motor circuit (20) having an AC motor (22) and a door latch circuit (30),
characterized,
in that the motor circuit (20) and the door locking circuit (30) can be activated via a single common electronic switching element (41). Circuit according to claim 1,
characterized,
in that the door locking circuit (30) is switched through continuously when actuated via the single common electronic switching element (41), wherein the motor circuit (20) can be interrupted simultaneously by at least one electromechanical switch (23). Circuit according to a preceding claim,
characterized,
that the single electronic switching element (41) is a triac or a thyristor. Circuit according to a preceding claim,
characterized,
in that the door locking circuit (30) has a switch (32) and / or a mechanism for locking the door, which can be activated by a PTC bimetallic element. Circuit according to a preceding claim,
characterized,
that two electromechanical switches (23.1, 23.2) can be used in the motor circuit, which are connected to the winding of the AC motor rotor (22.1) or to the winding of the AC motor field (22.2) and interrupt the motor circuit (20) in a first switching state and cause in a second switching state, a reversal of the direction of rotation of the AC motor (22). Circuit according to Claim 5,
characterized,
that the motor circuit (20) in addition to the two electromechanical switches (23.1, 23.2) for reversing the direction of rotation of the AC motor (22) and to interrupt the motor current, a further electromechanical switch relay (24) for field switching, wherein the electromechanical switch (24) for Field switching is connected to the other winding of the AC motor (22), as the winding, which is connected to the two electromechanical switches (23.1, 23.2) for reversing the direction of rotation and interrupting the motor current.

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