Control circuit for water bath heating box

Abstract

The utility model discloses a control circuit for a water bath heating box, which comprises a ground wire, a three-phase line and a neutral line, and is characterized in that a first line, a second line, a third line, a fourth line, a fifth line, a sixth line, a seventh line and an eighth line are arranged between the three-phase line and the neutral line in parallel, the front ends of the three-phase line and the first line are provided with a first air switch, the neutral line is provided with a second air switch at the front end of the first line, the rear end of the three-phase line is provided with a rectifier and a first resistor, the front ends of the ground wire, the three-phase line and the neutral line are connected with an external wire inlet terminal, and the three-phase line is connected with a heating pipe terminal. And the heating pipe terminal is arranged between the rectifier and the first resistor. The utility model has the advantages of small starting current and small impact on a power grid; the on-off frequency of the heating load is reduced, and the service life of the cable is prolonged; temperature control is precise and accurate; output can be automatically adjusted according to different use degrees, energy is saved, and consumption is reduced; and the fault rate of elements is low, and the service life is long.

Description

Technical Field

[0001] The utility model relates to the field of water bath heating equipment, and more specifically to a control circuit for a water bath heating box. Background Art

[0002] Water bath is a heating method in chemical laboratories that uses water as a heat transfer medium. The container of the heated substance is placed in water, and the boiling point of water is 100°C. This method is suitable for heating temperatures below 100°C. Water bath heating avoids excessive intensity and uncontrollable temperature caused by direct heating, and can heat smoothly.

[0003] However, the water bath heating equipment in the prior art uses a small current to control a large current, uses a large load switch (contactor), and directly closes and opens the heating tube circuit. The advantages during use are: 1. The electrical circuit is simple, the components are universal parts, and the price is cheap; 2. The maintenance is convenient, the maintenance cost is low, and less professional knowledge is required; 3. The operation is simple. However, the above methods have the following defects: 1. The temperature control is rough and the deviation range is large; 2. The starting current is large, and the impact on the power grid is large; 3. The frequency of load on and off is high, the frequency of cable impact is high, and the cable life is shortened; 4. Each operation is full power output, and the energy consumption is high; 5. Because of frequent actions, the component life is short. Utility Model Content

[0004] In order to solve the above problems, the purpose of the utility model is to provide a control circuit for a water bath heating box with a small starting current and a small impact on the power grid; reduce the frequency of power on and off of the heating load, reduce line impact, and extend the service life of the cable; the temperature control is precise and accurate, and the deviation range is small; the output can be automatically adjusted according to different usage levels, saving energy and reducing consumption; the component failure rate is low and the service life is long.

[0005] According to one aspect of the utility model, a control circuit for a water bath heating box is provided, which includes: a ground wire, a three-phase wire and a neutral wire, characterized in that the three-phase wire and the neutral wire are arranged in parallel: a first line, a second line, a third line, a fourth line, a fifth line, a sixth line, a seventh line and an eighth line, a first air switch is arranged at the front end of the three-phase wire and the first line, a second air switch is arranged at the front end of the neutral wire at the front end of the first line, a rectifier and a first resistor are arranged at the rear end of the three-phase wire, the front ends of the ground wire, the three-phase wire and the neutral wire are connected to the external incoming line terminal, the three-phase wire is connected to the heating tube terminal, and the heating tube terminal is arranged between the rectifier and the first resistor. By using an adjustable control switch, the control switch can be infinitely adjusted by controlling the current size, so that the starting current is small and the impact on the power grid is small.

[0006] In some embodiments, a power indicator light is provided on the second circuit, and the opening and closing state of the circuit is determined by the power indicator light.

[0007] In some embodiments, a first power terminal is provided on the third circuit, and the first power terminal is connected to a temperature controller terminal.

[0008] In some embodiments, the fourth line is provided with a second power terminal, and the second power terminal is connected to the SCR control terminal. By connecting the temperature controller terminal and outputting power from the SCR control terminal, it is possible to accurately check the temperature and respond to the final control of power output.

[0009] In some implementations, a first control knob and a first relay are disposed on the fifth line.

[0010] In some embodiments, the front end of the sixth circuit is provided with: a second relay, a third relay, and a second control knob in sequence, the rear end of the second control knob is connected in parallel with a fourth relay and a low-temperature contact of the temperature controller, and the rear end of the low-temperature contact of the temperature controller is provided with a high-temperature alarm point of the temperature controller and a fifth relay. The monitoring temperature of the temperature controller is refined by connecting the low-temperature contact of the temperature controller and the high-temperature alarm point of the temperature controller.

[0011] In some embodiments, a sixth relay and a remote control switch are provided on the seventh line, the rear end of the remote control switch is connected to the sixth line and is located between the high temperature alarm point of the temperature controller and the fifth relay, and an operation indicator light is provided at the rear end of the remote control switch.

[0012] In some embodiments, the front end of the eighth line is provided with an SCR fault output terminal, and the rear end of the SCR fault output terminal is connected in series with a fault indicator light and a seventh relay. The SCR fault output terminal enables the component protection function to be complete, the fault detection function can be used, the load device can be safely protected, and a fault indication code can be provided for quick processing.

[0013] In some embodiments, the first power terminal of the temperature controller is connected to the temperature controller terminal, the temperature controller terminal is connected to NC and NO, the temperature controller terminal outputs to the SCR control terminal, the SCR control terminal outputs to the SCR fault output terminal, and the second power terminal outputs to the SCR control terminal.

[0014] In some embodiments, the remote control switch outputs a liquid level signal, an operation signal, a fault signal, a remote local signal, and a remote start / stop signal.

[0015] Compared with the prior art, the utility model discloses a control circuit for a water bath heating box, which has the advantages of small starting current and small impact on the power grid; reduced on and off frequency of the heating load, reduced line impact, and extended cable service life; precise and accurate temperature control and small deviation range; automatic output adjustment according to different usage levels, energy saving and consumption reduction; low component failure rate and long service life; by using an adjustable control switch, the control switch is infinitely adjusted by controlling the current size, so that the starting current is small and the impact on the power grid is small; by connecting the temperature controller terminal and the SCR control terminal to output power, accurate temperature inspection and response can be achieved, and the power output can be finally controlled; through the SCR fault output terminal, the component protection function is complete, the fault detection function can be achieved, the load device can be safely protected, and a fault indication code can be provided for fast processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a control circuit for a water bath heating box of the utility model;

[0017] Figure 2 It is the wiring diagram of the temperature controller terminal and SCR control terminal of the control circuit for the water bath heating box of the utility model;

[0018] Figure 3 It is a control switch wiring diagram of a control circuit for a water bath heating box of the utility model. DETAILED DESCRIPTION

[0019] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0020] In the description of the present utility model, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection of two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meaning of the terms can be understood according to the specific circumstances.

[0021] like Figure 1 As shown, the control circuit for the water bath heating box of the utility model comprises: a ground line 1, a three-phase line 2 and a neutral line 3, characterized in that the three-phase line 2 and the neutral line 3 are arranged in parallel:

[0022] The first line 4, the second line 5, the third line 6, the fourth line 7, the fifth line 8, the sixth line 9, the seventh line 10 and the eighth line 11, the front end of the three-phase line 2 and the first line 4 is provided with a first air switch 12, the front end of the neutral line 3 is provided with a second air switch 13, the rear end of the three-phase line 2 is provided with a rectifier 14 and a first resistor 15, the front end of the ground line 1, the three-phase line 2 and the neutral line 3 is connected to the external incoming line terminal 16, the three-phase line 2 is connected to the heating tube terminal 17, and the heating tube terminal 17 is provided between the rectifier 14 and the first resistor 15. The heating tube terminal 17 is directly connected to the heating tube, and the adjustable control switch is used to control the current size to adjust the control switch steplessly, so that the starting current is small and the impact on the power grid is small. The rear ends of the first line 4, the second line 5, the third line 6, the fourth line 7, the fifth line 8, the sixth line 9, the seventh line 10 and the eighth line 11 are connected to the control device.

[0023] like Figure 2 As shown, a power indicator light 51 is provided on the second circuit 5. The power indicator light 51 is used to determine the opening and closing state of the circuit.

[0024] The third circuit 6 is provided with a first power terminal 61 , and the first power terminal 61 is connected to the temperature controller terminal 18 .

[0025] The first power supply terminal 61 of the temperature controller is connected to the temperature controller terminal 18, the temperature controller terminal 18 is connected to NC and NO, the temperature controller terminal 18 outputs to the SCR control terminal 19, the SCR control terminal 19 outputs to the SCR fault output terminal 111, and the second power supply terminal 71 outputs to the SCR control terminal 19. The current output from the temperature controller terminal 18 to the SCR control terminal 19 is 4-20MA, and the PT ground wire 100 platinum resistance is input to the temperature controller terminal 18. The current relay is connected to the SCR control terminal 19.

[0026] The fourth line 7 is provided with a second power terminal 71, which is connected to the SCR control terminal 19. By connecting the temperature controller terminal 18 and outputting power from the SCR control terminal 19, the temperature can be accurately checked and the power output can be controlled in response.

[0027] The fifth circuit 8 is provided with a first control knob 81 and a first relay 82. The first control knob 81 is a remote / local knob. The coil voltage of the first relay 82 is AC220V.

[0028] The front end of the sixth circuit 9 is provided with: a second relay 91, a third relay 92 and a second control knob 93 in sequence. The rear end of the second control knob 93 is connected in parallel with a fourth relay 94 and a temperature controller low temperature contact 95. The rear end of the temperature controller low temperature contact 95 is provided with a temperature controller high temperature alarm point 96 and a fifth relay 97. The monitoring temperature of the temperature controller is refined by connecting the temperature controller low temperature contact 95 and the temperature controller high temperature alarm point 96. The second control knob 93 is a heating knob. The fifth current relay coil voltage is AC220V

[0029] The seventh line 10 is provided with a sixth relay 101 and a remote control switch 102 . The rear end of the remote control switch 102 is connected to the sixth line 9 and is located between the high temperature alarm point 96 of the temperature controller and the fifth relay 97 . The rear end of the remote control switch 102 is provided with an operation indicator light 103 .

[0030] like Figure 3 As shown, the remote control switch 102 outputs liquid level signals, operation signals, fault signals, remote local signals and remote start / stop signals.

[0031] The front end of the eighth line 11 is provided with an SCR fault output terminal 111, and the rear end of the SCR fault output terminal 111 is connected in series with a fault indicator light 112 and a seventh relay 113. The SCR fault output terminal 111 enables the component protection function to be complete, the fault detection function can be achieved, the load device can be safely protected, and a fault indication code can be provided for quick processing.

[0032] The above are only some embodiments of the present invention. It should be pointed out that for ordinary technicians in this field, other modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. Control circuit for water bath heating box, including: A ground wire, a three-phase wire and a neutral wire, characterized in that the three-phase wire and the neutral wire are arranged in parallel: a first line, a second line, a third line, a fourth line, a fifth line, a sixth line, a seventh line and an eighth line, a first air switch is provided at the front end of the three-phase wire and the first line, a second air switch is provided at the front end of the first line of the neutral wire, a rectifier and a first resistor are provided at the rear end of the three-phase wire, the front ends of the ground wire, the three-phase wire and the neutral wire are connected to external incoming line terminals, the three-phase wire is connected to the heating tube terminal, and the heating tube terminal is provided between the rectifier and the first resistor.

2. The water bath heating box control circuit according to claim 1, characterized in that: A power indicator light is provided on the second line.

3. The control circuit for a water bath heating box according to claim 2, characterized in that: The third circuit is provided with a first power terminal, and the first power terminal is connected to a temperature controller terminal.

4. The control circuit for a water bath heating box according to claim 3, characterized in that: The fourth circuit is provided with a second power terminal, and the second power terminal is connected to the SCR control terminal.

5. The control circuit for a water bath heating box according to claim 4, characterized in that: The fifth circuit is provided with a first control knob and a first relay.

6. The control circuit for a water bath heating box according to claim 5, characterized in that: The front end of the sixth circuit is provided with: a second relay, a third relay and a second control knob in sequence, the rear end of the second control knob is connected in parallel with a fourth relay and a low-temperature contact of a temperature controller, and the rear end of the low-temperature contact of the temperature controller is provided with a high-temperature alarm point of the temperature controller and a fifth relay.

7. The control circuit for a water bath heating box according to claim 6, characterized in that: The seventh circuit is provided with a sixth relay and a remote control switch, the rear end of the remote control switch is connected to the sixth circuit and is located between the high temperature alarm point of the temperature controller and the fifth relay, and the rear end of the remote control switch is provided with an operation indicator light.

8. The control circuit for a water bath heating box according to claim 7, characterized in that: The front end of the eighth line is provided with an SCR fault output terminal, and the rear end of the SCR fault output terminal is provided with a fault indicator light and a seventh relay in series.

9. The control circuit for a water bath heating box according to claim 8, characterized in that: The first power terminal of the temperature controller is connected to the temperature controller terminal, the temperature controller terminal is connected to NC and NO, the temperature controller terminal outputs to the SCR control terminal, the SCR control terminal outputs to the SCR fault output terminal, and the second power terminal outputs to the SCR control terminal.

10. The control circuit for a water bath heating box according to claim 9, characterized in that: The remote control switch outputs liquid level signals, operation signals, fault signals, remote local signals and remote start / stop signals.

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