CN2132207Y

CN2132207Y - Electronic automatic frost melted device

Info

Publication number: CN2132207Y
Application number: CN 92213895
Authority: CN
Inventors: 康视田
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-05-08
Filing date: 1992-05-08
Publication date: 1993-05-05
Anticipated expiration: 2002-05-08

Abstract

The utility model discloses an electronic automatic frost melted device, comprising a temperature difference change detection comparison circuit which outputs a corresponding signal to a frost melted control circuit according to the detected temperature difference change. The frost melted control circuit executes the action of frost melting according to the control signal input by the temperature difference change detection comparison circuit. The frost melted control circuit is also connected with a frost melted reliability assurance circuit. A power circuit supplies the required power supply with each circuit. The utility model has the advantages that the control precision is in (+/-) 0.5 DEG C and when the frost exists, the electronic automatic frost melted device works and when the frost does not exist, the electronic automatic frost melted device does not work and the energy and the time are saved. The utility model has the advantages of simple structure and low cost.

Description

Electronic automatic frost melted device

The utility model relates to the physical technique field, is the control or the control of the temperature in the regulating system of on-electric variable, specifically, is so that the device of electricity consumption is the device of temperature variation feature, that be used to be scheduled to.

The refrigeration plant of all employing axial flow blower forced convections, all necessary defrost problem that solves evaporator surface.Defrost mode commonly used has: manually defrost, semi-automatic defrost and full-automatic defrost etc.Full-automatic defrost device both domestic and external almost is the programmed control of employing time decision entirely at present, promptly begins defrost behind the compressor operating certain hour, stops automatically behind the defrost certain hour.Though this timing controlled formula defrosting device is simple in structure, science not, because the thickness of evaporator surface frost layer is not only relevant with compressor operating time, but also relevant with factors such as the moisture of depositing article and humidity.Thereby the defrost of above-mentioned existing timing controlled formula exists obvious defects, frostization arranged not sometimes, though can frostlessly carry out defrost on the contrary again sometimes.

The purpose of this utility model provide a kind of can be according to frosting situation automatic defrosting, reliable operation, automatic electronic simple in structure frost device.

Technical solution of the present utility model is: a kind of automatic electronic frost device, comprise that a difference variation detects comparator circuit, it gives a defrost control circuit according to detected difference variation output corresponding signal, the defrost control circuit detects the control signal execution defrost action that comparator circuit is sent into according to difference variation, the defrost control circuit also is connected to a defrost reliability and guarantees circuit, and a power circuit provides required power supply for above-mentioned each circuit.

Defrost reliability of the present utility model guarantees in the circuit evaporator temperature sensor is arranged, reliability guaranteed clamping circuit before it became defrost of electric signal input with the temperature inversion of experiencing, reliability stops clamping circuit after reaching a defrost, and above-mentioned two clamping circuits are exported corresponding clamper signal again.

Reliability guarantees in the clamping circuit defrost operation voltage comparer of accepting the evaporator temperature sensor output signal is arranged before the defrost of the present utility model, defrost operation voltage comparator output signal makes the work of a defrost action amplifier, output clamper control signal, a defrost working value initialization circuit provides reference voltage for defrost operation voltage comparer.

Reliability stops in the clamping circuit defrost final voltage comparer of accepting the evaporator temperature sensor output signal being arranged after the defrost of the present utility model, defrost final voltage comparator output signal makes a defrost stop amplifier work, output clamper control signal, a defrost stop value initialization circuit provides reference voltage for defrost final voltage comparer.

Difference variation of the present utility model detects in the comparator circuit and comprises two temperature sensors that are located at refrigeration plant air inlet and air outlet respectively, a temperature difference comparer is accepted and more above-mentioned two signals that temperature sensor is sent into, and provide temperature signal output control signal to remove to trigger a controllable silicon, controllable silicon output switching signal.

A defrost signal processing circuit of working under the switching signal control that difference variation detection comparator circuit produces is arranged in the defrost control circuit of the present utility model, its output signal makes an amplifier job, amplifier drives a defrost executive circuit output defrost control signal, and the defrost signal processing circuit is connected to a delay control circuit.

Defrost executive circuit in the utility model is also controlled a defrost display circuit.

Evaporator temperature sensor in the utility model all adopts transistor PN junction sensor with the temperature sensor that is located at refrigeration plant air inlet and air outlet.Certainly, also can adopt other forms of temperature sensor.

The utility model has the advantages that: circuit structure is simple, low cost of manufacture, and dependable performance can be carried out automatic defrosting according to the frosting situation.Reached white defrost has been arranged, the frostless more satisfactory effect of not changing, make defrost break away from the past and reached by the programmed control of time decision fully, not only help improving the refrigeration and the serviceability of refrigeration plant, and tangible energy saving effect is arranged by the substance control of temperature decision.Owing to adopted transistor PN junction sensor, and designed high-precision regulated power supply, can make defrost control design temperature within ± 0.5 ℃, can satisfy various refrigeration plant requirements, applicability is good.

The utility model is described in further detail below in conjunction with drawings and Examples:

Fig. 1 is the electrical schematic diagram of the power supply that adopts in a kind of automatic electronic frost device of the present utility model.

Fig. 2 is the electrical schematic diagram of the defrost main body circuit in a kind of automatic electronic frost device of the present utility model.

Fig. 1, Fig. 2 have described an embodiment of the present utility model.Comprise defrost main body circuit and power circuit.

In defrost main body circuit by integrated circuit (IC) 3a, potentiometer W1, temperature sensor VT1, VT3, capacitor C 4, C5, C6, C7, resistance R 3, R4, R5, R6, R6, R7, R8, diode D5, controllable silicon MCR etc. has formed difference variation and has detected comparator circuit, temperature sensor VT1, VT3 are located at respectively on refrigeration plant air inlet and the air outlet, detect intake air temperature level V1 and air outlet temperature levels V2 respectively, and regulator potentiometer W1 can set temperature difference △ V.Owing to adopt the PN junction temperature sensor of negative temperature coefficient among the design, when the frost layer is not thick, V2＞V1+ △ V, integrated circuit (IC) 3a exports electronegative potential, when the constantly thickening of frost layer, the temperature difference will constantly diminish, when V2-V1＜△ V, integrated circuit (IC) 3a state overturns, the output noble potential, trigger controllable silicon MCR conducting, working power is provided for the defrost control circuit.Regulator potentiometer W1 can make the temperature difference be set between 0.5-5 ℃ and select.

By integrated circuit (IC) 3b, triode BG1, BG2, diode D6, D7, D10, capacitor C 8, potentiometer W3, resistance R 9, R10, R11, R12, R13, R14, R15, the defrost relay J, LED 2 grades have been formed the defrost control circuit, when its under the control of controllable silicon MCR electric after, make integrated circuit (IC) 3b output noble potential, triode BG2 saturation conduction, the adhesive of defrost relay J, defrost indication LED 2(Y) light, defrost begins automatically, with the increase of defrost time, by triode BG1, capacitor C 8, the delay circuit that resistance R 9 is formed constantly raises capacitor C 8 positive terminal potentials, through needed time, integrated circuit (IC) 3b state turnover, triode BG2 ends, relay J discharges, and defrost stops automatically.

Also designed in the utility model by integrated circuit (IC) 3C, potentiometer W6, capacitor C 9, diode D8, triode BG3, reliability guarantees clamping circuit before the defrost that resistance R 18, R19, R21 etc. form.It accepts the signal that the temperature sensor circuit of being made up of temperature sensor VT2, capacitor C 10, resistance R 16 etc. is sent into.Temperature sensor VT2 is located on the evaporator of refrigeration plant, detects the evaporator surface temperature by it.Control defrost owing to adopt temperature difference mode; when refrigeration plant just starts, defrost finishes during the motor delayed startup; shut down compressor to temperature and stop refrigeration; and blower fan breaks down under the situation such as shut down; the refrigeration plant air inlet and the air outlet temperature difference also may be smaller, and make equipment produce misoperation.Set by potentiometer W6, make the evaporator surface temperature be lower than (as-5 ℃) before the subzero a certain setting value, integrated circuit (IC) 3c exports noble potential always, triode BG3 saturation conduction, electronegative potential is clamped down in integrated circuit (IC) 3a in aforementioned defrost control circuit output, the defrost misoperation can not produced.So just make defrost begin to be restricted by two factors simultaneously, promptly must satisfy the air inlet and the air outlet temperature difference simultaneously must reach the evaporator surface temperature and must be lower than subzero a certain set-point temperature less than a certain set-point temperature, and defrost could begin.

In the present embodiment also by integrated circuit (IC) 3d, potentiometer W2, W4, W5 diode D9, triode BG4, capacitor C 11, resistance R 17, R20, R22 etc. have formed the reliable clamping circuit that stops after the defrost.It also accepts evaporator temperature sensor VT2 output signal.After defrost begins; the evaporator surface temperature will raise; when rising to a certain setting value above freezing (as+5 ℃); integrated circuit (IC) 3d state is overturn; the output noble potential makes triode BG4 saturation conduction, and electronegative potential is clamped down in aforementioned IC3b output; triode BG2 ends; relay J discharges, and defrost is stopped, like this; defrost stops restricted by two factors; defrost stops when the evaporator surface temperature is elevated to design temperature, and also stops when the defrost time reaches the schedule time, and regulator potentiometer W2 can make the thermal control final temperature set between 5-10 ℃; and can make with temperature and be controlled to be the master, the time is controlled to be the protection that lags behind.Integrated circuit (IC) 3a in this enforcement, IC3b, IC3c, IC3d are one four voltage comparator integrated circuit LM339.Each temperature sensor VT1, VT2, VT3 respectively utilize two NPN transistor to be connected into diode form formation.Utilize transistorized constant current source characteristic as temperature probe.

Power circuit in the present embodiment.Owing to adopted transistor PN junction sensor to consider that its temperature coefficient is less in the present embodiment,, designed high-precision regulated power supply for guaranteeing control accuracy.By transformer B, commutation diode D1-D4, diode D5, DW LED 1, capacitor C 1, C2, C3, resistance R 1, R2, regulator block IC1(model AN7812), IC2(model AN7809), this electric power output voltage V1, V2 are used for defrost main body circuit.The same prior art of its principle of work is omitted description at this.

Claims

1, a kind of automatic electronic frost device, it is characterized in that: comprise that a difference variation detects comparator circuit, it gives a defrost control circuit according to detected difference variation output corresponding signal, the defrost control circuit detects the control signal execution defrost action that comparator circuit is sent into according to difference variation, the defrost control circuit also is connected to a defrost reliability and guarantees circuit, and a power circuit provides required power supply for above-mentioned each circuit.

2, automatic electronic frost device according to claim 1, it is characterized in that: the defrost reliability guarantees in the circuit evaporator temperature sensor is arranged, reliability guaranteed clamping circuit before it became defrost of electric signal input with the temperature inversion of experiencing, reliability stops clamping circuit after reaching a defrost, and above-mentioned two clamping circuits are exported corresponding clamper signal again.

3, automatic electronic frost device according to claim 2, it is characterized in that: reliability guarantees in the clamping circuit defrost operation voltage comparer of accepting the evaporator temperature sensor output signal is arranged before the defrost, defrost operation voltage comparator output signal makes the work of a defrost action amplifier, output clamper control signal, a defrost working value initialization circuit provides reference voltage for defrost operation voltage comparer.

4, automatic electronic frost device according to claim 2, it is characterized in that: reliability stops in the clamping circuit defrost final voltage comparer of accepting the evaporator temperature sensor output signal being arranged after the defrost, defrost final voltage comparator output signal makes a defrost stop amplifier work, output clamper control signal, a defrost stop value initialization circuit provides reference voltage for defrost final voltage comparer.

5, according to claim 1 or 2,3,4 described automatic electronic frost devices, it is characterized in that: difference variation detects in the comparator circuit and comprises two temperature sensors that are located at refrigeration plant air inlet and air outlet respectively, a temperature difference comparer is accepted and more above-mentioned two signals that temperature sensor is sent into, and export control signal according to temperature signal and remove to trigger a controllable silicon, controllable silicon output switching signal.

6, according to claim 1 or 2,3,4 described automatic electronic frost devices, it is characterized in that: a defrost signal processing circuit of working under the switching signal control that difference variation detection comparator circuit produces is arranged in the defrost control circuit, its output signal makes an amplifier job, amplifier drives a defrost executive circuit output defrost control signal, and the defrost signal processing circuit is connected to a delay control circuit.

7, automatic electronic frost device according to claim 6, it is characterized in that: the defrost executive circuit is also controlled a defrost display circuit.

8, according to claim 2 or 3,4 described automatic electronic frost devices, it is characterized in that: evaporator temperature sensor adopts transistor PN junction sensor.

9, automatic electronic frost device according to claim 5, it is characterized in that: the temperature sensor that is located at refrigeration plant air inlet and air outlet adopts transistor PN junction sensor.