DE19604579A1 - Control device for monostable solenoid valves - Google Patents

Description

The invention relates to a device and a method to operate one or more monostable Solenoid valves especially for non-contact control sanitary fittings.

Monostable solenoid valves are characterized by that to maintain the open position of the Ven the system's solenoid is permanently energized must become. Also characteristic of such Ak tuatorsysteme is that to open the valve (Plunger movement) required energy much higher forth than the energy requirement to maintain the Opening status (holding the plunger in the open position lung). When designing or dimensioning the Solenoid systems by the valve manufacturer has this too take into account that by inductance and equal  current resistance possible at given nominal operating voltage active power of the magnet system (plunger movement) even under unfavorable operating conditions (e.g. max. Operating pressure, high medium temperature, aging or Deposits, wear) is sufficient, the plunger safely to move to the open position. Furthermore, the Magnet systems (and thus inductance and effective resistance stood) of this valve design so dimensioned that when operating the system at the lower tolerance limit the nominal operating voltage a safe opening of the Ven tils is guaranteed.

However, this leads to the fact that after the actual opening process (movement of the plunger into the open position lung) which are usually in constant equality or alternation voltage operated solenoid during opening Valve duration with too much energy is opened. In order to ensure thermal To avoid overloading the system will be such Magnet systems on the one hand very "generous" dimensio niert, on the other hand, these are in terms of operation Overvoltage very sensitive. The magnetic coils derar systems are therefore - system or function urgently - always to the respective care provider voltage (operating voltage) of the system adjusted.

In non-contact controlled sanitary fittings to control the water supply among other things monostabi le solenoid valves used. In most cases, who which they operate with direct current. Because of the Be drive safety, the voltage range is between 6 and 30 volts. Are these fittings connected to the AC network operated, a suitable transformer must be interposed  will. The current is rectified using a electronic circuit. Are these fittings on egg connected to an existing low-voltage network the solenoid of the valve to the voltage range be coordinated. Since there are different low in the field voltage networks (direct or alternating current) would have to each time the solenoid valve is tuned to the network the. This results in a variety of products.

Another disadvantage of the monostable valves that in the open position they are constantly running on electricity be flowed. Is that at the solenoid valve The voltage cannot be adapted to the magnet system This makes the coil very hot and the winding through burn.

Because these solenoid valves in the magnetic circuit (coil) so are designed to open the valve even at un favorable operating conditions (maximum operating pressure, Medium temperature, aging) is guaranteed after the actual opening process in the valve too unnecessarily much energy implemented in the solenoid. The The coil of the solenoid valve used must therefore - to for example damage to the system due to overhit exclude voltage - to the respective operating voltage be adjusted.

The invention has for its object a Vorrich device and a method for operating monostable Solenoid valves with different electrical ver to create supply voltage.

This task is accomplished with the device features of the Claim 1 and with the procedural features of the An Proverb 6 solved.  

Further refinements of the invention are in the An say 2 to 5 and 7 to 8.

With the measures according to the invention it is achieved that on the one hand the energy required to operate a mono stable solenoid valve to the absolutely necessary Minimum can be reduced and on the other hand a si Safe operation of a monostable solenoid valve in an egg wide supply voltage range without adjustment solution / modification of the solenoid coil is made possible. Here, the energy for the magnetic coil for the Opening process (tightening energy) and the energy for Maintaining the open position (holding energy) un be designed differently, the suits gie and the holding energy according to the current Be drive voltage (level of supply voltage) control is heard.

For a given supply voltage, this means that the current through the solenoid coil can be reduced for the duration of the opening position (hold) after the opening process (pull-in) and, in addition, the absolute value of the current strengths during the opening process or hold state to the currently specified supply voltage is adaptable (Wirklei stung P _L ∼ U _L · I _L ).

With the measures according to the invention, he becomes is enough that the monostable solenoid valve with respect the solenoid no longer to the given operation voltage must be adjusted. The monostable magnetic vein til can thus function without any disadvantages in operate over a wide voltage range.  

In addition, with the proposed measures he will is enough that the power consumption of monostable mag netvalves can be optimized (minimized) at simultaneous improvement of functional safety. Voltage fluctuations (mains voltage failures) corrected with the proposed valve control.

Since with the device according to the invention a minimal Power consumption takes place during the open position, can make the magnet system simpler (cheaper) will. There is also no risk of overheating the solenoid when operating on overvoltage.

The power supply (transformer) for the control circuit and the actuator for the valve control can be be dimensioned smaller with regard to the nominal power (Factor 1/10). They are therefore cheaper to manufacture or it can be per power supply or transformer or actuator more solenoid valves are operated.

An embodiment of the invention is in the drawing shown and will be described in more detail below ben. It shows

Fig. 1 is a block diagram of a non-contact controlled sanitary door;

Fig. 2 is a graph of a pulse width modulated signal in the case of a low operating voltage;

Fig. 3 is a graph of a pulse width modulated signal in the case of a high operating voltage.

The control for a sanitary fitting consists of a voltage supply 1 , which is connected on the input side to an alternating current network (U∼), a Microcon troller 4 , an infrared light sensor system 5 with transmitter 51 and receiver 52 , an actuator 2 and a monostable solenoid valve 3 . On the output side, the voltage supply 1 produces the rectified, but not stabilized, operating voltage U _B for the solenoid valve 3 and the stabilized DC voltage U _S for supplying the microcontroller 4 . The microcontroller 4 itself is - if necessary via a voltage divider - also if connected to the U _B output of the voltage supply 1 , so that it can always determine the currently available operating voltage for the solenoid valve 3 , for example by means of an on-chip ADC. In the event that activation of the solenoid valve 3 is required as a result of presence detection, the microcontroller 4 controls the actuator 2 , which in the simplest case can be designed as a switching transistor, by means of a pulse-width-modulated signal (SIGNAL).

This signal, which is shown in FIG. 2 for the case of a "low" operating voltage U _B , but in FIG. 3 for the case of a "high" operating voltage U _B , consists of two parts:

During the time period t _A1 or t _A2 it follows the output of the "tightening pulse" for the monostable magnetic valve 3 . The absolute duration of this signal part is calculated by the microcontroller 4 as a function of the determined current operating voltage U _B using a calculation rule or a table.

After expiry of the valve opening phase during t _A1 resp. T _A2 a rectangular signal with the period T is output during the period of the valve activation (opening time). The pulse / pause ratio of this signal component is in turn calculated by the microcontroller 4 as a function of the current operating voltage for the solenoid valve 3 , so that pulse width modulation for the control signal of the solenoid coil results.

The effective value of the control energy for the solenoid valve 3 for the holding state is directly proportional to the pulse / pause ratio (degree of modulation) τ₁ / T or τ₂ / T, the control power during the opening phase, however, is proportional to the control times t _A1 and t _{A2 of} the control signal SIGNAL. This means that both the tightening pulse energy and the holding energy are regulated, which allows the solenoid valve to be used within a wide range of voltages regardless of the actual nominal operating voltage of the solenoid coil, or the safe operation of the valve even in the case of strongly fluctuating voltages To ensure operating voltage and at the same time to minimize the energy for controlling the solenoid valve.

Claims (8)

1. Device for operating one or more monostable solenoid valves, in particular for non-contact controlled sanitary fittings, characterized in that a device is provided with which the input voltage is detected and one of which is the nominal voltage or the one for the functional area of the solenoid valve ( 3 ) Corresponding de, generated by a periodic interruption or pulse width modulation effective output voltage to the solenoid valve ( 3 ) can be fed. 2. Apparatus according to claim 1, characterized in that as a device for generating the effekti ven output voltage, a microcontroller ( 4 ) is provided, with which the required output voltage can be generated by means of suitable software (calculation rule, table) via the pulse width modulation. 3. Device according to claim 2, characterized in that

• a power supply unit ( 1 ) that can be connected to the AC network is provided, with which on the one hand a rectified operating voltage for the solenoid valve ( 3 ) and on the other hand a stabilized DC voltage for supplying the microcontroller ( 4 ) can be provided,
• - The microcontroller ( 4 ) is also connected to the rectified operating voltage and is designed such that when activating the solenoid valve ( 3 ) a pulse width modulated signal for an actuator ( 2 ) it can be generated.

4. The device according to claim 3, characterized in that the actuator ( 2 ) is formed out as a switching relay. 5. Apparatus according to claim 3 or 4, characterized in that a voltage divider is arranged between the microcontroller ( 4 ) and the operating voltage. 6. A method for operating one or more monostable solenoid valves, in particular for non-contact controlled sanitary fittings, characterized in that the input voltage is measured and, depending on the measured input voltage, the required output voltage for the solenoid valve ( 3 ) with a pulse width modulation, it produces becomes. 7. The method according to claim 6, characterized in that in dependence on the measured input voltage pulse-width-modulated signals who who with which an actuator ( 2 ) for one or more solenoid valves ( 3 ) is controlled. 8. The method according to claim 7, characterized in that the signal in each case consists of two parts, where in the first part of the signal comprises the time period t _A for the tightening pulse by a Microcon troller ( 4 ) as a function of the determined current operating voltage is determined using a calculation rule or a table, while the two-th part of the signal in the valve activation includes square-wave signals with the period T, in which the pulse / pause ratio (τ₁ / T or τ₂ / T) from the microcontroller ( 4 ) in dependence the current operating voltage of the solenoid valve ( 3 ) is also determined.