JPS6111560A - Control circuit for electric water heater - Google Patents

Abstract

PURPOSE:To obtain good economical property without using useless daytime electric power by permitting conduction of an electric heater for a given time in daytime. CONSTITUTION:A daytime electric heater control circuit 17 opens and closes a relay 18 only while a timer circuit 16 is operating a timer operation. The relay 18 is kept in the opened condition thereof while the timer operation is being stopped and midnight electric power is being detected by a midnight electric power detecting circuit 10. A night electric heater control circuit 19 opens and closes the relay 20 while the midnight electric power is being detected by the midnight electric power detecting circuit 10. The relay 20 holds the opened condition while the midnight electric power is being stopped. The time-up of a timer circuit 16 is caused at 5 o'clock in the afternoon, for example, and timer stopping signal is outputted. The daytime electric heater control circuit 17 holds the opened condition of the relay 18 by said signal and stops the conduction of a daytime electric heater 5. According to this method, the useless daytime electric power may be saved.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a control circuit for an electric water heater. This allows electricity to be applied to only 2 pieces and 7 inches.

Conventional configuration and its problems A 2-load, 2-power-source electric hot water heater that uses daytime electric power to install a daytime electric heater that uses daytime power in addition to the conventional electric water heater that uses late-night power to reduce the size of the hot water storage tank and save energy. The daytime electric heater is used to replenish the small amount of hot water used for cooking in the morning. The most effective way to energize is
This is the period from the time the electricity is cut off in the morning and late at night until the evening. After that, it is more energy efficient to turn on the power at midnight. For example, if a large amount of hot water in the hot water storage tank is used for taking a bath at 8 p.m., water is supplied to the hot water storage tank and the electric heater is energized during the day until the midnight electricity starts. However, if the power is turned on after 8 p.m., it will not be possible to use it that day, and there is no point in turning on the power. Moreover, daytime electricity is more expensive than late-night electricity, making it less economical, and heating up occurs earlier, leading to greater heat dissipation loss, which is contrary to energy conservation.

OBJECTIVES OF THE INVENTION 3/7 In view of the conventional problems mentioned in 1., the present invention provides a daytime electric heater that heats water in a hot water storage tank using daytime electric power.
By using a timer to enable power to be turned on only for a certain period of time, this system eliminates wasteful daytime power supply and improves economic efficiency, as well as solving the problem of the boiling time being too early, which goes against energy conservation. .

Structure of the Invention The basic structure of the present invention to achieve the above object is as follows: A nighttime electric heater that heats the water in the hot water storage tank using late-night electricity; The vehicle is equipped with a daytime electric heater that heats the vehicle, and a timer circuit enables the daytime electric heater to be energized only within a certain fixed period of time.

DESCRIPTION OF THE EMBODIMENTS Fig. 1 is a configuration diagram of a two-load, two-power water heater. It is equipped with a nighttime electric heater 4 that heats by energization, a daytime electric heater 5 that heats by daytime electric power, and a boiling sensor 6 that detects the temperature of water in a hot water storage tank, and a control circuit 7 controls energization of the heaters 4 and 5.

FIG. 2 shows a block diagram of the circuit of this embodiment.

8 is a late-night power supply that is turned on only for a certain period of time in the middle of the night.

Reference numeral 9 indicates an earth leakage i- or disconnection switch, and 1o indicates a late-night power detection circuit, which outputs a signal for turning on or stopping the late-night power. Reference numeral 4 denotes an electric heater at night, which is energized by the operation of the relay 20. 11 is a contact point of the relay 20. 12 is constantly energized by daytime power supply. 13 is an earth leakage breaker, and 5 is a daytime electric heater, which is energized by the operation of a relay 18. 14 is a contact point of the relay 18. A power supply circuit 16 generates a DC voltage used for control signals. Reference numeral 16 denotes a timer circuit, which starts a timer operation in response to a signal indicating that the late-night power is stopped in the late-night power detection circuit. 17 is a daytime electric heater control circuit which opens and closes the relay 18 only while the timer circuit 16 is operating. While the timer operation is stopped and while the late-night power detection circuit 10 is detecting the late-night power, the relay 18 remains open. 19 is the 6-bay night electric heater control circuit.

The relay 20 is opened and closed while the late-night power detection circuit 10 detects the late-night power, and the relay 20 remains open while the late-night power is stopped.

Figure 3 shows the operating state. A is a conventional example, in which the daytime electric heater may be constantly energized while the electric power is stopped at midnight depending on the boiling state of the hot water storage tank. b is the case of this embodiment. When the late-night power is stopped at 7 am, the late-night power detection circuit 1o outputs a late-night power stop signal. In response to this signal, the nighttime electric heater control circuit 19 opens the relay 20 and stops energizing the nighttime electric heater 4. At the same time, the timer circuit 16 starts timer operation and outputs a signal indicating that the timer is operating to the daytime electric heater control circuit 17.

Let the timer operation time be T. In this example, it is 10 hours. The daytime electric heater control circuit 17 opens and closes the relay 18 depending on the boiling state in the hot water storage tank while there is a signal to stop power at night from the late night power detection circuit 10 and a timer operation signal from the timer circuit 16. and controls the energization of the vaneter 5 during the daytime.

After 10 hours, the 5:00 pm timer circuit 16 times up and outputs a signal to stop the timer. In response to this signal, the daytime electric heater control circuit 17 holds the relay 18 in an open state and stops energizing the daytime electric heater 6. This results in
The wasted daytime power in the hatched area shown in FIG. 3 is saved.

Late-night power detection circuit 1 is activated by turning on late-night power at 11 p.m.
o outputs a signal for late-night power supply. The late-night electric heater control circuit 19 opens and closes the relay 2o to control the electricity supply to the night-time electric heater 4 based on the signal B and the boiling state in the hot water storage tank.

This state continues until 7:00 a.m. the next day, and after that, the same operation as described above is repeated.

Effects of the Invention As described above, according to the present invention, by allowing the electric heater to be energized during the daytime only for a certain period of time, it is possible to avoid wasteful use of daytime power and to achieve good economic efficiency. It also has the effect of preventing the water from boiling too quickly and improving energy efficiency.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a two-load two-power water heater, FIG. 2 is a block diagram of a circuit according to an embodiment of the present invention, and FIG. 3 is an operation sequence diagram. 1...Hot water storage tank, 4...Night electric heater, 6...Daytime electric heater, 16...
・Timer circuit.

Claims (2)

[Claims] (1) A nighttime electric heater that heats the water in the hot water storage tank using late-night electric power, and a daytime electric heater that uses daytime electric power to heat the water in the hot water storage tank, and the daytime electric heater A control circuit for an electric water heater that allows the timer circuit to turn on electricity only for a certain period of time. (2) The control circuit for an electric water heater according to claim 1, wherein a start signal for a timer that controls the energization time of the electric heater during the daytime is given by a energization stop signal for late-night electricity.