KR910008817Y1 - Breaker of a water tank - Google Patents

Abstract

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Description

Low Water Level Circuit Breakers

1 is a circuit diagram of a low water level breaker of the present invention hot water tank.

2 is a circuit diagram of a second embodiment of the present invention.

3 is a circuit diagram of a third embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

1: main device 2: relay

3: transformer 4: rectifier

5, 6: resistor 7: zener diode

8: water tank 9: sensor

10: Drive TR 11: Reset S / W

12: SCR 13: Capacitor

14: resistance

The present invention relates to a low water level shutoff device for a heated water tank such as a boiler, and in particular, to block the operation of the main device when the water level in the heated water temperature drops below the prescribed level, thereby preventing the main device or the water tank from being overheated or damaged. An electronic low level breaker.

In general, a constant water level must be maintained at all times in a heated water bath provided in a boiler. When the water level in the water tank drops below a certain level, water must be replenished to maintain the water level above a certain level. Because of this, if the water level in the water tank is lowered below a certain level, if the water is not replenished, there is a problem that the main apparatus or the water tank such as a boiler is overheated or consumed.

Therefore, in the electronic low level circuit breaker which controls the operation of the main device such as a boiler by the relay, when the relay does not operate because the constant water level is always maintained in the water tank, the main device operates normally (non-contact of the relay). The relay operates only when the water level in the water tank is low level to block the operation of the main device to prevent power consumption of the low level breaker and heat generation on the circuit.In addition, the sensor input part of the relay driving circuit maintains low impedance In order to avoid the influence of induced noise and to reduce the ionization of water in the bath, extremely small currents must be supplied to the sensor.

Conventionally, a low water level circuit breaker has been used for such a problem. The circuit breaker applies an alternating current to a sensor provided at a predetermined position of the tank to rectify the change, and uses it as a driving current of the sensor input unit. Although the AC current applied to the circuit breaker was easy to drive a low impedance sensor input part, the current is matched to the low impedance as it is, so the sensor current increases and the life of the sensor is shortened. In addition to the DC power supplied to the relay to be rectified by applying a separate AC power source has the disadvantage that the production cost is increased because two power is required.

Therefore, the present invention has been devised to solve the above problems, and it is possible to reduce the manufacturing cost, minimize the power consumption, and minimize the current supplied to the sensor by operating the low-level circuit breaker using only a single DC power supply. The purpose of the present invention is to provide a low level breaker that can reduce the ionization of water, thereby extending the life of the sensor.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The low-level breaker of the warm water tank according to the present invention, as shown in the circuit diagram of FIG. 1, a relay (2) for controlling the main device (1) capable of driving a boiler, etc. and a transformer (3) for supplying power. Is connected to the transformer 3, and a rectifier 40 for rectifying current is connected to the rectifier 4, and the rectifier 4 includes two resistors 5 and 6 and a zener diode 7 and a water tank 8. It is composed of a circuit connected to a drive TR (transistor) 10 which is operated by the sensor 9 and operates the relay 2. That is, the relay 2 has a circuit structure connected to the contact point (B) at all times, and when the drive TR 10 is driven, the relay device 2 is operated as the contact point (A), and the main device 1 is " OFF " ) Is not driven, the main unit (1) is "ON" to return to the contact point (B) to operate the boiler, etc. This drive TR (10) is in direct contact with water at a certain position in the water tank (8) When the water in the water tank 8 is filled with the appropriate level 8a, the two contacts 9a of the sensor 9 are intermittently intermittent by the sensor 9 composed of two contacts 9a and 9b. , 9b) flows to the rectifier 4 side instead of the relay 2 when the current flows through the drive TR 10 as the current flows to the contact 9a by the ionization action of the water. It is said that it is not driven and the relay 2 stays at the contact point (B) through the transformer (3). The eoon voltage is applied directly to the host device (1) via a relay (2) to which the host device 1 is "ON".

On the contrary, when the water level in the water tank 8 is lowered to the low water level 8b below the proper level, no current flows through the two contacts 9a and 9b of the sensor 9, and the voltage is driven through the zener diode 7 to drive TR ( The main unit 1 is " OFF " by moving the relay 2 contact point to the (A) contact point while flowing to the relay 2 via 10). Say state.

To explain these relationships in more detail, when the water level in the water tank 8 is above the proper water level 8a, the voltage EI is caused by the current i in the water tank 8 flowing through the sensor 9 so that the voltage of the Zener diode 7 The bias voltage becomes lower than the intrinsic breakdown voltage so that the bias voltage E2 does not occur. When the water level in the water tank B is low, the current i in the water tank 8 becomes extremely small, so that the voltage EI is applied to the applied voltage ( Since it is higher than the breakdown voltage of the zener diode 7 which is almost the same as E), the bias voltage E2 of the drive TR 10 is generated.

In addition, the resistor 5 is coupled to the zener diode 7 for setting the bias current of the drive TR 10 to match the impedance of the sensor 9 and the drive TR 10, and over biases the drive TR 10. It also serves to limit the current. In addition, the resistor 6 is for preventing the malfunction by lowering the impedance of the drive TR 10, and the capacitor 2a provided in the relay 2 is smoothed to prevent the relay 2 from hunting by the power supply ripple. It is a capacitor.

2 shows another embodiment of the present invention, in which a reset (RE-SET) switch 11 is additionally installed in the transformer 3 and a driving SCR (contactless relay, 12) is provided, and the smoothing capacitor 13 which keeps the anode and the cathode of the SCR 12 at a constant electric potential is provided.

3 shows another embodiment of the present invention and has a structure in which a driving SCR 12 and a breather resistor 14 are provided.

In addition, instead of the zener diodes 7 installed in the second and third embodiments, the SCR 12 can be used instead of the trigger diode for generating the pulse pulse. When the current is reduced to improve the ionization of water, the trigger diode can be used to obtain a better effect.

Next, the operation of the circuit breaker of the present invention will be described.

The low-level breaker of the present invention, as shown in FIG. 1, first turns on the ON switch (not shown) of the main apparatus 1 when the water level in the water tank 8 is at the proper level 8a. 3) stepped down to flow through the rectifier 4 through the resistor 5 to the sensor 9 in the water tank 8 and at the same time a part of the main unit 1 from the contact a of the transformer 3 ') Is applied to the relay (2) through the contact (b) of the transformer (3), the relay (2) is always in the contact point of the (B) (relay "OFF") state (A) Unless it is a contact, the voltage applied to this relay 2 enters the other side (b ') of the main apparatus 1 as it is, and operates this main apparatus 1, and a boiler etc. are operated. That is, when the water level in the water tank 8 is filled above a certain water level, the electric current is caused by ionization of water in the water tank 8 at the first contact 9a of the rectifier 4-> resistance 5-> sensor 9. Is applied to the second contact point 9b. At this time, the bias voltage E2 does not occur and the drive TR 10 does not move the relay contact point A to the contact point A. The main device 1 is normally operated by maintaining the contact and supplying power to the main device 1.

However, if the water level in the water tank 8 falls below the proper water level and lowers to the low water level 8b, there is no ionizing material, that is, water, between each of the contacts 9a and 9b of the sensor 9 provided in the water tank 8. When the current flows to the sensor 9, the voltage E1 which is almost the same as the voltage E is applied to the drive TR 10 as the voltage other than the breakdown voltage of the zener diode 7 becomes the bias voltage E2. Therefore, the power flows from the drive TR 10 to the relay 2. At this time, the relay 2 moves away from the contact point (B) to the contact point (A), whereby the power flowing to the main device 1 through the relay 2 is cut off, and the main device 1 is "OFF", such as a boiler. Operation stops.

In this way, after the water level in the water tank B is lowered and the boiler is stopped, in order to start the boiler again, the start switch of the main device 1 is in the "ON" state. Turn it "ON".

Of course, before turning it "ON" again, the water level in the water tank 8 is raised to the normal position and there is an opportunity to check and check the various devices in the apparatus once again.

In another embodiment of the present invention, as shown in FIG. 2, when the water level in the water tank 8 is lowered to the low water level 8b so that the driving SCR 12 is "turned on", the characteristics of the SCR 12 (gate voltage is applied). When turned on, the SCR 12 can be operated even if the water level in the water tank 8 becomes higher than the proper water level 8a according to the characteristic of returning to " turn-off " only after the anode power is cut off regardless of the gate voltage. Does not return to " turn off " and the SCR 12 returns to " turn off " only after confirming that the water level in the water tank 8 is above the proper level and pressing the reset switch 11 to cut off the power supply voltage. At this time, even if the reset switch 11 is set to the original position, the SCR 12 remains in the " off " state unless the water level in the water tank 8 becomes the low water level 8b.

In another embodiment of the present invention, as shown in FIG. 3, when the water level in the water tank 8 returns to the proper water level 8a, the gate voltage E2 of the SCR 12 is immediately extinguished. SCR 12 does not immediately "turn off" and remains "turned on" until the pulse wave top dead center of voltage E. (Here, the description of the embodiment of FIG. 2 that the SCR 12 "turns on" when the water level in the water tank 8 falls below the proper level is omitted.) However, the power supply pulse in the state where the gate voltage E2 is extinguished. When the voltage falls, the SCR is " turned off " because the capacitor 2a charge charge is immediately transferred to the cathode of the SCR 12 through the path of the breather resistor 14 and current i. That is, when the gate voltage E2 is extinguished, the capacitor 2a is discharged so that the anode of the SCR 12 has a negative potential with respect to the cathode when the pulsation waveform falls of the power supply voltage E. As a result, the SCR 12 is discharged. Is "turned off". Of course, the capacitor 2a acts as a smoothing capacitor at the " turn-on " of the SCR 12, and acts as a " turn-off " trigger element of the SCR 12 when the gate voltage E2 is extinguished.

As described above, the low-level breaker of the device is "OFF" immediately when the water level in the water tank falls below the proper level, and the operation of the boiler is stopped, and the water is filled in the water tank. It is not ON, but only after returning the start switch to the "OFF" position, it must be "ON" again to make the main unit "ON" and to operate the boiler.

At this time, the main device and all other parts are checked before the start switch is “ON”, and thus the damage of the device can be prevented in advance, and in the conventional circuit configuration, the sensor current is about 4.5 mA, which is as low as 0.15 mA in the present invention. As the ion prevention effect is improved to about 1/30, even if a single DC power supply is used, the sensor current is extremely small, and water in the tank reduces the ionization shape, thereby extending the life of the sensor.

Claims (3)

A relay 2 for controlling the main apparatus 1 and a transformer 3 for supplying power are connected to a main apparatus 1 for driving a boiler, etc., and the rectifier 4 is provided with a rectifier 4 in the transformer 3. (4) constitutes a circuit to which the driving TR 10 for operating the relay 2 is operated by the resistors 5 and 6 and the sensor 9 installed in the zener diode 7 and the water tank 8. Low water level breaker of the hot water tank, characterized in that. The low water circuit breaker of claim 1, wherein the relay (2) comprises a circuit in which a SCR (12) which is a contactless relay and a zener diode are connected to each other. The low water circuit breaker of claim 2, wherein the relay (2) is connected to an SCR (12) which is a contactless relay and a trigger diode.