JPS5942606Y2 - hot water machine - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a water heater having an anti-corrosion circuit.

Figure 1 shows all the anti-corrosion circuits for conventional water heaters.

In the figure, 1 is a hot water-like can body, 2 is an anti-corrosion electrode installed so as to penetrate the side wall of this can body 1 and protrude inside.
The penetrating portion is supported by the can body 1 by an insulator.

Reference numeral 3 denotes a constant voltage circuit that applies full DC voltage to the anticorrosion electrode 2, and also has the function of detecting the anticorrosion current and detecting the water level in the can body 1.

4 is a rectifier circuit including a step-down transformer, and 5 is a combustion control circuit, which includes a safety device and has an output contact 5a.

As this output contact 5a, an output contact for water level detection in the constant voltage circuit 3, a relay contact connected in series with safety devices, etc. is used.

6 is a combustion blower, 7 is a power switch, and 9 is a commercial AC power source.

The can body 1 is provided with a ground terminal, and when the water level in the can body 1 exceeds the anti-corrosion electrode 2, an anti-corrosion current flows, and the water level is detected by detecting this current, and the combustion control circuit 5 The combustion blower 6 is driven by the excitation, and combustion starts.

Further, when the water level has not reached the corrosion protection electrode 2, the output contact 5a of the combustion control circuit 5 is opened, the blower 6 is in a non-operating state, and the combustion operation is stopped.

In this way, the water level is detected by detecting the anti-corrosion current, but in this configuration, the relay is turned on.

Since extra power is consumed when turned off, the anti-corrosion voltage is likely to fluctuate, and since the anti-corrosion voltage is low, the current is also small, which may result in malfunction.

The reason for this depends on the water quality, but when a DC voltage is applied to the electrode 2, the conductive substance dissolved in the water in the can body 1 adheres to the electrode 2 like electroplating. Even when the water level is low, current flows between the electrode 2 and the can body 1 through the deposits, and there is a risk that the water level will be incorrectly detected.

This idea was made to eliminate the above-mentioned drawbacks; an electrode for water level detection is provided above the anti-corrosion electrode, a full alternating current voltage is applied to this electrode, and the water level is detected based on the presence or absence of current. The purpose of the present invention is to provide a water heater that can reliably prevent dry heating.

This invention will be explained below based on the illustrated embodiments.

Fig. 2 shows an embodiment of this invention, in which 10 is an electrode disposed above the anti-corrosion electrode 2 for water level detection, 11 is an electrode for applying an alternating voltage to this electrode 10, and detecting the current flowing through it. A water level detection circuit 12 is a step-down transformer provided on the input side of the rectifier circuit 4, and its output is supplied to the rectifier circuit 4 and the water level detection circuit 11.

The water level detection circuit 11 has an output contact that is turned on or off depending on whether the water level is above or below the electrode 10, and this output contact is used instead of the output contact of the conventional constant voltage circuit 3. It is inserted into the control circuit 5.

Therefore, in this case, the constant voltage circuit 3 does not need a water level detection function.

In addition, 1 is a can body, 6 is a combustion blower, 7 is a power switch, 9 is a commercial AC power source, and 5a is an output contact of the combustion control circuit 5.

With this configuration, the water level in the can body 1 is detected by the electrode 10 and the water level detection circuit 11, and only when the water level exceeds the electrode 10K, the blower 6 is driven in cooperation with the combustion control circuit 5 to maintain the combustion state. becomes.

In this case, since an alternating current voltage is applied to the electrode 10, the electrode 10 is constantly cleaned and adhesion of conductive substances is prevented, so water level detection is performed reliably and safety is ensured.

As described above, according to this invention, the water level detection electrode is provided above the corrosion protection electrode, and the entire DC voltage is applied to the corrosion protection electrode and the AC voltage is applied to the water level detection electrode, so that the corrosion protection operation is performed. Good and reliable water level detection operation.
Operational reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a corrosion protection circuit of a conventional water heater, and FIG. 2 is a circuit diagram of the essential parts of an embodiment of the water heater according to this invention. 1... Can body, 2... Anti-corrosion electrode, 3...
... Constant voltage circuit, 4 ... Rectifier circuit, 5 ...
... Combustion control circuit, 5a ... Output contact, 5
...Combustion blower, 7...Power switch, 9...Commercial AC power supply, 10...Water level detection electrode, 11... Water level detection circuit, 12.
...Step-down transformer. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A ground terminal metal is provided on the side of the can body 1, and an anti-corrosion electrode 2 to which a positive DC voltage is applied is protruded from the side wall of the can body into the can body to form an anti-corrosion circuit that conducts an anti-corrosion current and detects the water level inside the can body 1. In a water heater equipped with a water level detection circuit 11, an electrode 10 to which a full alternating current voltage is applied is provided above the corrosion prevention circuit 2, and the water level is detected by the presence or absence of current flowing through this electrode. The water heater is characterized in that the output contact of the water level detection circuit 11 is inserted and connected to the combustion control circuit 5 in series with a safety circuit, etc.