ES2201510T3 - ELECTRONIC CONTROL PROCEDURE FOR DRAIN PUMPS USED IN ELECTRICAL APPLIANCES. - Google Patents

Abstract

The invention is related to a method that provides electronic control of working periods of the synchronous or asynchronous drain pump motors used in electrical home appliances such as dish washing machines and washing machines. During normal use of the home appliance, while the drain pump (2) is operating, the values of the current taken is audited by a microprocessor (1) and compared with the previous values of "rates of current drawn while operating loaded (while there is water in the machine) and without load (while there is no water)" which are loaded into the memory of the microprocessor and when the desired balance is attained, the drain pump, by arriving at a decision that operation is done without water, stops. To measure the current drawn by the drain pump (2), a circuit formed by a "resistance based on manganin" (3) an "op-amp" (4) and an "ac-dc converter" (5), is being used.

Description

Electronic control procedure for pumps of drain used in household appliances.

This invention relates to a process that provides electronic control of operating periods of motors, synchronous or asynchronous, of drain pumps used in household appliances such as dishwashers and washing machines.

In dishwasher control systems and existing washing machines, the drain pump works during a period of time established by the washing program. East set time period is greater than the time the pump drain needs to evacuate water outside under normal circumstances For example, a drain pump of 16 liters / minute can empty the amount of 5 liters of water from a washing machine in a short period of time, but it works for a set period of 1 minute. Similarly, the bombs of drain works during half or more of the operating period in existing control systems without any need for it. This unnecessary operation makes, once the water has been evacuated, the drain pump continue to run without water until Complete the operating time.

In the document EP-0-107-234 A se employs a water level detector to prevent the pump from drain continues to run after the water level in the tank has reached zero.

When the drain pump runs without water generates a very high noise emission in the washing machine when absorbing air. Although there is no water left in the washing machine, the drain pump still working and this generates electricity consumption unnecessary. For example, in the normal program of a dishwasher, a 34W drain pump running for an average of 5.5 minutes, use 3.2wH of energy. If the drain pump has functioned unnecessarily for 50% of this time, it will have used 1.6 wH of energy in the same way unnecessary.

The drain pump, during operation, draws power from the network while there is water in the dishwasher (with load) and while there is not (no load). For example, a pump 34W drain if put into operation with a load greater than 3.5 liters, draws more or less 125mA of current, but once the water has evacuated, the current drawn by the pump decreases up to about 110mA.

The objective of this invention is to establish a procedure that is based on the difference in current drawn from the network through the drain pump when operating with and without load, is control the pump operating time, the amount of current drawn from the network by the pump with electronic control, and parallel to this, prevent energy consumption from seeing Increased through unnecessary operation, reduce noise and shorten the duration of the program.

In order to achieve these goals, the proposed procedure is explained below by doing reference to the attached drawings, in which:

Figure 1 is the diagram of the electronic circuit that controls the pump with a microprocessor (1) and measures the current drawn by the pump
of drain (2).

Figure 2 is the circuit diagram in the which the "current transformer" (6) is used instead of "Manganin-based resistance" (3).

Figure 3 is the circuit diagram in which a "Hall effect transistor" (7) is used instead of a "Manganin-based resistance" (3).

In the process according to this invention, the Drain pump is controlled by a microprocessor (1). For carry it out laboratory experiments are performed and it records the difference in current drawn by the pump to Run with and without load. These values are stored in memory. of the microprocessor (1).

 \ 

carga}/|_{sin

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carga}) en el microprocesador con el programa que se va a utilizar.After this phase the current ratios are recorded with and without load (| with

 \ 

load} / | _ without

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load}) in the microprocessor with the program to be used.

During operation, to measure the current drawn by the drain pump (2), is used (Figure 1) a circuit formed by a "resistance based on Manganin "(3), an" operational amplifier " ("op-amp") (4) and a "transformer AC-DC (CA-CC) "(5). In this circuit, instead of a "Manganin-based resistance" (3) a "current transformer" (6) or a "Hall effect transistor" (7).

A directly proportional voltage is formed in Manganin-based resistance (3) that connects to the line from the drain pump (2) on the microprocessor (1). East voltage is transmitted to an op-amp circuit of such so that the highest value is increased up to 5V AC (alternating current). The voltage increasing by a level of 0-5 VAC in the op-amp circuit (4) converts to direct current (DC) in the circuit AC-DC transformer (5) and transmitted to microprocessor (1). This information that reaches the microprocessor (1) How analog is then converted to digital information. Yes the voltage transmitted to the microprocessor (1) is constantly greater than 5V means that the drain pump (2) is blocked up.

 \ 

carga}). Para comparar los valores entre sí puede ser preferible un período de tiempo diferente a cinco segundos. A continuación del registro de la corriente para el funcionamiento con carga (|'_{con

 \ 

carga}) con cada medida realizada, la corriente registrada para el funcionamiento con carga se compara y la ratio determinado (|_{con

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carga}/|_{medido}) se compara al ratio de funcionamiento con y sin carga (|_{con

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carga}/|_{sin

 \ 

carga})que se registró en la memoria del microprocesador durante los estudios de laboratorio previos después de que fuera determinado.During normal use of the dishwasher, after 7 seconds from the start of the drain pump (2), the extracted current begins to be measured. This period of time, depending on how long it takes for the pump to start working, can vary between 5-10 seconds. The measurement time varies depending on the microprocessor and the software used. In the present process, the time required for this is 640 µg with a PIC 16C74 microprocessor. The values recorded during the first five seconds after starting the measurements are compared to each other and the highest value is recorded in memory as the loaded value of operation (| '_ with

 \ 

load}). To compare the values with each other, a period of time other than five seconds may be preferable. Following the registration of the current for operation with load (| '_ with

 \ 

load}) with each measurement taken, the current recorded for the operation with load is compared and the determined ratio (| with

 \ 

load} / | measured) is compared to the operating ratio with and without load (| with

 \ 

load} / | _ without

 \ 

load}) that was recorded in the microprocessor memory during previous laboratory studies after it was determined.

 \ 

carga}/|_{medido} \geq (|_{con

 \

carga}/|_{sin

 \ 

carga}), se entiende que la bomba de desagüe está funcionando sin carga y se para. En caso de que las medidas realizadas alcancen 5V de modo continuo, se toma la decisión de que la bomba quede bloqueada (2), y en este caso, se le informa al usuario a través de un procedimiento de aviso.When the equivalence value is obtained | '_ with

 \ 

load} / | measured} \ geq (| with

 \

load} / | _ without

 \ 

load}), it is understood that the drain pump is running without load and stops. In the event that the measurements taken reach 5V continuously, the decision is made that the pump is blocked (2), and in this case, the user is informed through a warning procedure.

Claims (3)

1. A control procedure for drain pumps used in household appliances that includes a microprocessor (1), a program and reference values obtained as a result of laboratory experiments that are stored in the microprocessor (1), characterized by: - Record the value obtained from the currents used by the drain pump while operating with and without load in the form of a ratio such as (| with

 \ 

load} / | _ without

 \ 

load}) in the microprocessor (1) together with the program to be used; - Start measuring the current drawn during the use of the machine based on an activation time of the drain pump 5 to 10 seconds. - Record the highest value obtained comparing the values obtained within the first five seconds or in a different time period of measurement, such as operating current with memory load. - Compare the operating current with load (| '_ with

 \ 

load}) with each measured value and compare the ratio obtained (| 'with

 \ 

load} / | measured) with the values previously recorded in the microprocessor as results of laboratory experiments. - Stop the machine when the equivalence is given | '_ {with

 \ 

load} / | measured} \ geq (| with

 \

load} / | _ without

 \ 

load}) assuming that the drain pump is working without load. 2. A method according to Claim 1 in which, in order to measure the current used by the aforementioned drain pump: - a circuit consisting of a "op-amp" (4) and a "transformer of CC-CA "(5) together with a" resistance based on manganin "(3) or a" current transformer "(6) or a "Hall effect transistor" (7) connected in series to the line electric drain pump (2). - The voltage formed in the "manganin-based resistor" (3), in the "current transformer" (6) or in the "Hall effect transistor" (7) is increased so that the maximum value is 5V in the
"op-amp" (4). - High current of 0-5 V AC on the Op-amp circuit (4) is converted to direct current (DC) and is transmitted to the microprocessor (1). - This analog data is converted to data digital 3. A method according to Claim 2 characterized in that when the voltage supplied to the microprocessor (1) permanently exceeds 5V, it is decided that the drain pump (2) is blocked, and the user is informed through some type
of warning.