CN106903979B - Plane transfer printing device - Google Patents

Abstract

The invention relates to the technical field of heat transfer printing, and discloses a planar transfer printing device. It includes an upper table, a lower table, a movable support rod, a first high-frequency oscillating circuit, a second high-frequency oscillating circuit and a support platform, the upper table is set on the support platform, and the upper table and the lower table are parallel and passed through the movable The upper table and the lower table overlap each other when they are pressed together, the first high-frequency oscillating circuit and the second high-frequency oscillating circuit are arranged in the support platform, and the resonant coil of the first high-frequency oscillating circuit It is arranged on the lower table, and the resonant coil of the second high-frequency oscillating circuit is arranged on the upper table, and the first resonant coil and the second resonant coil overlap when the upper table and the lower table are pressed together. When transferring, the copper clad laminates placed between the upper and lower tables form eddy currents to generate heat, the temperature of the copper clad laminates is stable, and the transfer is completed at one time.

Description

A plane transfer device

technical field

The invention relates to the technical field of heat transfer printing, in particular to a planar transfer printing device.

Background technique

Rubber shaft transfer printing machine is a transfer printing equipment commonly used in various laboratories at present. It emits infrared radiation with a main dial of 2.5-15 μm in the direction of the gap of the rubber shaft through the electrothermal radiation element and the reflection device to achieve heat transfer. Use the rotation of the rubber shaft to achieve large-area transfer printing requirements. Using this method to transfer printing requires high temperature and high pressure to transfer completely. However, due to the uneven temperature distribution on the rubber shaft, the temperature of the copper clad laminate is easy to change during the transfer process. , resulting in incomplete pattern transfer, requiring secondary transfer; in addition, as long as the rubber shaft transfer machine is turned on, it will heat up and generate a lot of energy consumption, and the heating process requires a heat-conducting medium that will also cause energy loss; secondly, heat conduction through the medium It also makes the transfer efficiency lower. Therefore, its energy transfer method limits its efficiency and heating area. If a small-scale heating device with controllable heating area and less loss in the energy transfer process can be provided, the above problems will be solved and convenience will be brought to people's lives.

Contents of the invention

The technical problem to be solved by the present invention is to provide a planar transfer printing device for the above existing problems.

The technical scheme adopted by the present invention is as follows: a planar transfer printing device, which specifically includes an upper table, a lower table, a movable support rod, a first high-frequency oscillation circuit, a second high-frequency oscillation circuit and a support platform, and the upper table is set On the support table, the upper table and the lower table are arranged in parallel, and the upper table and the lower table are connected by movable support rods. When the upper table and the lower table are pressed together, they overlap each other. The first high-frequency The oscillating circuit and the second high-frequency oscillating circuit are arranged in the support platform, the first resonant coil of the first high-frequency oscillating circuit is arranged on the lower table, and the second resonant coil of the second high-frequency oscillating circuit is arranged on the upper table, The first resonant coil and the second resonant coil overlap when the upper table and the lower table are pressed together. When the distance between the upper table and the lower table is the farthest, the upper table and the lower table partially overlap, and at this time the upper table and the lower table are in a separated state.

Further, the movable support rod includes a first support shaft, a second support shaft, a third support shaft and a fourth support shaft parallel to each other, the first support shaft, the second support shaft, the third support shaft and the The fourth support shaft is connected to two opposite sides of the upper table and the lower table. When the distance between the upper table and the lower table is the farthest, the first support shaft, the second support shaft, the third support shaft and the fourth support shaft The axis is perpendicular to the upper table.

Further, one end of the first support shaft and the second support shaft are respectively hinged to one end of two opposite sides of the upper table, and the other ends of the first support shaft and the second support shaft are respectively hinged to two ends of the lower table. The non-ends of the opposite sides of the bar, one end of the third support shaft and the fourth support shaft are respectively hinged on the non-ends of the two opposite sides of the upper table, the third support shaft and the fourth support shaft The other ends are respectively hinged on one part of the two opposite sides of the lower table, and the first support shaft, the second support shaft, the third support shaft and the fourth support shaft can all be within a range of 90° along the hinge point at the hinge. internal activities.

Further, the upper surface of the lower table has a first groove, the first resonant coil is arranged in the first groove, the lower surface of the upper table has a second groove, and the second resonant coil is arranged in the second groove.

Further, the first resonant coil and the second resonant coil are respectively adhered to the upper surface of the lower table and the lower surface of the upper table.

Further, both the first high-frequency oscillation circuit and the second high-frequency oscillation circuit adopt a zero-voltage switching circuit (ZVS).

Further, the zero-voltage switching circuit includes a power supply, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a first high-frequency coil, a first transistor, a second transistor, and a third diode Tube, fourth diode, first diode, sixth diode, second inductance, third inductance; the first end of the first resistor and the first end of the second inductance, the fourth resistor The first end is connected to the positive pole of the power supply, the second end of the first resistor is connected to the first end of the second resistor, the second end of the first diode, the first end of the third diode, and the G of the first transistor. pole connection, the second end of the second inductance is connected with the first end of the first high-frequency coil and the first end of the third inductance, the second end of the fourth resistor is connected with the second end of the third resistor, The first end of the sixth diode, the second end of the fourth diode, and the G pole of the second transistor are connected, and the first end of the first diode is connected to the first end of the third inductor, the first The second end of the capacitor, the second end of the first high-frequency coil, and the D pole of the second transistor are connected, and the second end of the sixth diode is connected to the lower end of the second inductor, the first end of the first capacitor, and the second end of the second transistor. The first end of a high-frequency coil is connected to the D pole of the first transistor, the second end of the second resistor, the second end of the third diode, the S pole of the first transistor, and the second diode The second end, the first end of the third resistor, the first end of the fourth diode, the S pole of the second transistor, and the first end of the fifth diode are connected to the power ground, wherein the second inductor and the third The inductance is a freewheeling inductance, and the first high frequency coil is a resonant coil.

Further, the zero-voltage switching circuit further includes a protection circuit, the protection circuit is coupled between the power supply end and the first end of the first high-frequency coil, and includes a reference voltage generation circuit and a feedback loop, the reference voltage The generating circuit includes a parallel circuit and a seventh resistor, the parallel circuit includes a seventh Zener diode, an eighth resistor and a second capacitor connected in parallel, the first end of the parallel circuit is grounded, and the second end of the parallel circuit is coupled to connected to the first end of the seventh resistor, the feedback loop includes a third transistor, a first amplifier, a second amplifier and a ninth resistor, the first end of the third transistor is coupled to the power supply end, and the third transistor The second terminal of the third transistor is coupled to the first terminal of the first high-frequency coil, the control terminal of the third transistor is coupled to the output terminal of the first amplifier, and the second input terminal of the first amplifier is coupled to the second terminal of the parallel circuit. end, the first input end of the first amplifier is coupled to the output end of the second amplifier, the input end of the second amplifier is coupled to the first end of the first high frequency coil, and the output end of the second amplifier is coupled The ninth resistor is coupled to ground, and the third transistor is a field effect transistor or a MOS transistor or a triode.

Further, the protection circuit further includes a resistor network, a comparator, and a discharge path, the resistor network includes a tenth resistor, an eleventh resistor, a twelfth resistor, and a thirteenth resistor, and the first resistor of the tenth resistor terminal is coupled to the power supply terminal, the second terminal of the tenth resistor is coupled to the eleventh resistor and then grounded, the first terminal of the twelfth resistor is coupled to the power supply terminal, and the second terminal of the twelfth resistor After being coupled to the thirteenth resistor, it is coupled to ground, the second end of the tenth resistor is coupled to the first input end of the comparator, the second end of the twelfth resistor is coupled to the second input end of the comparator, and the discharge The path includes an N-MOS transistor connected in series and a fourteenth resistor, the output end of the comparator is connected to the control end of the N-MOS transistor, the second end of the N-MOS transistor is coupled to ground, and the N-MOS transistor The first end is coupled to the first end of the fourteenth resistor, and the second end of the fourteenth resistor is coupled to the second input end of the first amplifier.

Further, the tenth resistor and the twelfth resistor are matching resistors, the temperature coefficient of the eleventh resistor is greater than the temperature coefficient of the thirteenth resistor, and the resistance value of the eleventh resistor is smaller than that of the thirteenth resistor at normal temperature. value.

In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: when transferring, the upper and lower tables are used to sandwich the copper clad laminate, the temperature of the copper clad laminate will not change during the heating process, and the heating is uniform , It only needs one time to complete the transfer, avoiding the second transfer; at the same time, it realizes the eddy current heating of the copper clad laminate between the upper table and the lower table, avoids heat dissipation during heat conduction, and improves energy conversion efficiency.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the planar transfer device of the present invention when it is not pressed.

Fig. 2 is a structural schematic diagram of the planar transfer printing device of the present invention during lamination.

FIG. 3 is a schematic structural diagram of a zero voltage switching circuit 200 of the present invention.

FIG. 4 is a schematic structural diagram of a zero voltage switching circuit 300 with a protection circuit according to the present invention.

FIG. 5 is a schematic structural diagram of a protection circuit 400 of the present invention.

FIG. 6 is a schematic structural diagram of a further optimized protection circuit 500 of the protection circuit in FIG. 5 .

Fig. 7 is a temperature adjustment curve of an embodiment of the present invention.

Reference signs: support table-1, bearing-2, first resonant coil-3, second resonant coil-4, upper table-5, copper clad laminate-6, lower table-7, first support shaft-8, second Three supporting shafts-9.

Detailed ways

Below in conjunction with accompanying drawing, the present invention is described in detail.

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in Figure 1-2, a planar transfer printing device specifically includes an upper table 5, a lower table 7, a movable support rod, a first high-frequency oscillating circuit, a second high-frequency oscillating circuit, and a support table 1. The upper table 5 is arranged on the support table 1, the upper table 5 and the lower table 7 are arranged in parallel, the upper table 5 and the lower table 7 are connected by movable support rods, and the upper table 5 and the lower table 7 are pressed When the distance between the upper table 5 and the lower table 7 is the farthest, the upper table 5 and the lower table 7 partially overlap, and the first high-frequency oscillation circuit and the second high-frequency oscillation circuit are arranged on the supporting platform 1, the first resonant coil 3 of the first high-frequency oscillating circuit is arranged on the lower table 7, the second resonant coil 4 of the second high-frequency oscillating circuit is arranged on the upper table 5, and the upper table 5 and the lower table 7. The first resonant coil 3 and the second resonant coil 4 overlap during pressing. When transfer printing is required, the upper table 5 is pressed onto the lower table 7, and the copper clad laminate 6 is placed, and the first high frequency oscillating circuit and the second high frequency oscillating circuit resonate to make the first resonant coil 3 and the second resonant coil 3 resonate. The voltage of the coil 4 changes according to the sinusoidal law, and when it is put into the copper clad laminate 6, the eddy current heat generation is realized, and the pattern is transferred to the copper clad laminate 6; It can transfer completely; at the same time, eddy current heat generation does not require heat conduction medium, reducing energy consumption.

The movable support rod comprises a first support shaft 8, a second support shaft, a third support shaft 9 and a fourth support shaft parallel to each other, the first support shaft 8, the second support shaft, the third support shaft 9 and the fourth support shaft are connected to the two opposite sides of the upper table 5 and the lower table 7. When the upper table 5 and the lower table 7 are farthest away, the first support shaft 8, the second support shaft, the third The support shaft 9 and the fourth support shaft are perpendicular to the upper table. The movable support rod can make the upper table 5 and the lower table 7 flexibly be in a pressed state and a separated partial overlapping state, which is realized by only four support shafts, and the structure is simple and flexible.

One end of the first support shaft 8 and the second support shaft are respectively hinged on one end of two opposite sides of the upper table 5, and the other ends of the first support shaft 8 and the second support shaft are respectively hinged on the bottom of the lower table 7. The non-ends of the two opposite sides, one end of the third support shaft 9 and the fourth support shaft are respectively hinged on the non-ends of the two opposite sides of the upper table 5, the third support shaft 9 and the first The other ends of the four support shafts are respectively hinged on one part of the two opposite sides of the lower platform 7, where the hinge is realized by the bearing 2, the first support shaft 8, the second support shaft, the third support shaft 9 and The fourth support shafts can move within 90° along the hinge point of the hinge. The articulation of this embodiment is achieved by bearings, and the upper table 5 and the lower table 7 can be pressed together or separated. When the upper table 5 moves relative to the lower table 7, the first support shaft 8, the second support shaft, and the second support shaft The three supporting shafts 9 form an angle of 0°-90° with the upper table 5 or the lower table 7 .

The upper surface of the lower table 7 has a first groove, the first resonant coil 3 is arranged in the first groove, the lower surface of the upper table 5 has a second groove, and the second resonant coil 4 set in the second groove.

The first resonant coil 3 and the second resonant coil 4 are adhered to the upper surface of the lower table 7 and the lower surface of the upper table 5 respectively.

The first high frequency oscillating circuit and the second high frequency oscillating circuit adopt a zero voltage switching circuit (ZVS).

The zero voltage switching circuit 200 includes a power supply, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a first high frequency coil L1, a first transistor Q1, a second transistor Q2, the third diode D3, the fourth diode D4, the first diode D1, the sixth diode D6, the second inductance L2, the third inductance L3; the first end of the first resistor R1 It is connected with the first terminal of the second inductor L2, the first terminal of the fourth resistor R4 and the positive pole of the power supply, the second terminal of the first resistor R1 is connected with the first terminal of the second resistor R2, the first terminal of the first diode D1 Two terminals, the first terminal of the third diode D3, and the G pole of the first transistor Q1 are connected, and the second terminal of the L2 of the second inductance is connected with the first terminal of the first high-frequency coil L1 and the terminal of the third inductance L3. The first end is connected, the second end of the fourth resistor R4 is connected with the second end of the third resistor R3, the first end of the sixth diode D6, the second end of the fourth diode D4, the second transistor The G pole of Q2 is connected, the first end of the first diode D1 is connected to the first end of the third inductance L3, the second end of the first capacitor C1, the second end of the first high frequency coil L1, the second The D pole of the transistor Q2 is connected, the second end of the sixth diode D6 is connected to the lower end of the second inductor L2, the first end of the first capacitor C1, the first end of the first high frequency coil L1, the first transistor Q1 The D pole of the second resistor R2 is connected, the second end of the second resistor R2, the second end of the third diode D3, the S pole of the first transistor Q1, the second end of the second diode D2, the third resistor R3 The first end of the first end of the fourth diode D4, the S pole of the second transistor Q2, and the first end of the fifth diode D5 are connected to the power ground, wherein the second inductance L2 and the third inductance L3 are The freewheeling inductor, the first high frequency coil L1 is a resonant coil. The third diode D3 and the fourth diode D4 are Zener diodes, and the first diode D1 and the sixth diode D6 are fast recovery diodes. When the power supply voltage acts on VCC, the current starts to pass through the primary stages on both sides simultaneously and is applied to the drains of the first transistor Q1 and the second transistor Q2, that is, the D stage. The voltage will simultaneously appear on the gates of the first transistor Q1 and the second transistor Q2, that is, G electrodes, and start to turn on the first transistor Q1 and the second transistor Q2. Since no two components are exactly the same, one of the transistors such as the first transistor Q1 turns on faster than the other second transistor Q2, more current will flow through the first transistor Q1. The current passing through the second inductor L2 on the conduction side pulls down the G electrode voltage of the second transistor Q2 on the other side and starts to turn it off. At this time, there is a current in the third inductance L3 connected to the second transistor Q2. Since the current in the third inductance L3 cannot change abruptly, a high potential will be generated at this time and pass through the first high-frequency coil L1 to reach the first transistor of the first transistor Q1. At one end, the second transistor Q2 that was originally turned off due to the conduction of the first transistor Q1 is turned on again by the high potential generated by the third inductor L3, and at this time the first transistor Q1 will be turned off, and then the second inductor L2 will be turned on again. A high potential is generated, and there is a current, and so repeated, a high-frequency oscillation is formed. Therefore, LC resonance occurs between the first capacitor C1 and the first high-frequency coil L1, that is, the resonant coil, and makes the voltage change according to the sinusoidal law.

Figure 4 shows a schematic structural diagram of a zero-voltage switch circuit 300 according to an embodiment of the present invention. Compared with the zero-voltage switch circuit 200 shown in Figure 3, the zero-voltage switch circuit 200 also includes a protection circuit 400, as shown in FIG. 5, the protection circuit 400 is coupled between the power supply end and the first end of the first high-frequency coil L1, and includes a reference voltage generation circuit and a feedback loop. The reference voltage generation circuit includes a parallel circuit and a seventh Resistor R7, the parallel circuit includes a seventh Zener diode D7, an eighth resistor R8, and a second capacitor C2 in parallel, the first end of the parallel circuit is grounded, and the second end of the parallel circuit is coupled to the seventh resistor The first terminal of R7, the second terminal of the seventh resistor R7 is coupled to the power supply terminal VCC, the feedback loop includes the third transistor Q3, the first amplifier AM1, the second amplifier AM2 and the ninth resistor R9, the The first end of the third transistor Q3 is coupled to the power supply terminal VCC, the second end of the third transistor Q3 is coupled to the first end of the first high frequency coil L1, and the control end of the third transistor Q3 is coupled to the first The output end of the amplifier AM1, the second input end of the first amplifier AM1 is coupled to the second end of the parallel circuit, the first input end of the first amplifier AM1 is coupled to the output end of the second amplifier AM2, and the first amplifier AM1 is coupled to the output end of the second amplifier AM2. The input end of the second amplifier AM2 is coupled to the first end of the first high-frequency coil L1, the output end of the second amplifier AM2 is coupled to the ninth resistor R9 and then grounded, and the third transistor Q3 is a field effect transistor or MOS transistors or triodes, wherein the MOS transistors are preferably P-channel MOS transistors. The reference voltage generating circuit generates a reference voltage VREF, and the current of the third transistor Q3 is limited to a current value determined by the reference voltage VREF, the ninth resistor R9 and so on. The second amplifier AM2 is a current amplifier, which measures the current of the third transistor Q3, and the amplification factor is set to A. The output terminal of the second amplifier AM2 is connected to the ninth resistor R9, and the voltage at one end of the ninth resistor R9 can be expressed as

VR9=A*IQ3*R9 (1)

Wherein IQ3 is the current of the third transistor Q3, and the R9 is the resistance of the ninth resistor. In a steady state, the voltage at the second input terminal of the first amplifier AM1 is fixed at the reference voltage VREF, and the voltage at the input terminal of the second amplifier AM2 varies with the current of the third transistor Q3 and is smaller than the reference voltage at the first terminal of the first amplifier AM1 VREF, the third transistor Q3 maintains a minimum on-resistance. When the current IQ3 of the third transistor Q3 increases due to a circuit failure or other reasons, according to formula (1), the voltage at the first input terminal of the first amplifier AM1 also starts to increase and gradually approaches the reference voltage VREF, the voltage of the first amplifier AM1 The voltage at the output terminal also increases the on-resistance of the third transistor Q3 accordingly, thereby stabilizing the maximum current of the third transistor Q3 at

IQ3＝VREF/(A*R9) (2)

During the shutdown process of the system, the eighth resistor R8 discharges the second capacitor C2, and the voltage on the second capacitor C2 is zero. After the system is powered on, the power supply terminal VCC charges the second capacitor C2 through the seventh resistor R7, so that the voltage on the second capacitor C2 slowly increases from 0 to the reference voltage VREF. According to formula 2, the current IQ3 of the third transistor Q3 also gradually increases from 0 to VREF/(A*R9). That is, the protection circuit 400 shown in FIG. 4 can not only protect the overcurrent during operation, but also soft start the device during startup. The protection circuit 400 has soft-start and over-current protection functions, which can prevent the zero-voltage switching circuit 300 from burning out due to excessive current during startup or operation.

The protection circuit 400 further includes a resistor network, a comparator and a discharge path DS, denoted as a protection circuit 500, and the resistor network includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12 and a thirteenth resistor R13, the first end of the tenth resistor R10 is coupled to the power supply terminal VCC, the second end of the tenth resistor R10 is coupled to the eleventh resistor R11 and grounded, and the first end of the twelfth resistor R12 is coupled to the ground. connected to the power supply terminal VCC, the second end of the twelfth resistor R12 is coupled to the thirteenth resistor R13 and then grounded, the second end of the tenth resistor R10 is coupled to the first input end of the comparator CM1, the The second terminal of the twelfth resistor R12 is coupled to the second input terminal of the comparator CM1, the discharge path DS includes a series connected N-MOS transistor and the fourteenth resistor R14, and the output terminal of the comparator CM1 is connected to the N- The control terminal of the MOS transistor, the second terminal of the N-MOS transistor is coupled to the ground, the first terminal of the N-MOS transistor is coupled to the first terminal of the fourteenth resistor R14, and the second terminal of the fourteenth resistor R14 The terminal is coupled to the second input terminal of the first amplifier AM1. The resistor network reduces the impact of power fluctuations on the protection circuit 500, and the discharge path DS is used to discharge the second capacitor C2.

In one embodiment, the tenth resistor R10 and the twelfth resistor R12 are matching resistors with equal resistance (same temperature characteristics), and the temperature coefficient of the eleventh resistor R11 is greater than that of the thirteenth resistor R13, that is, the temperature rise When the value is high, the resistance increase characteristic of the eleventh resistor R11 is more obvious. At room temperature, the resistance of the eleventh resistor R11 is slightly smaller than the resistance of the thirteenth resistor R13 to ensure that the output of the comparator CM1 is low, and the discharge path DS remains closed, that is, it does not affect other circuits. When the temperature rises to the set temperature, since the resistance value of the eleventh resistor R11 increases more, the voltage at the first input terminal of the comparator CM1 will exceed the voltage at the second input terminal of the comparator CM1, and the comparator CM1 will output a high level, The discharge path DS starts to discharge the second capacitor C2, and the voltage of the second input terminal of the first amplifier AM1 decreases.

According to formula (2), since the voltage of the second input terminal of the first amplifier AM1 decreases, the current IQ3 passing through the third transistor Q3 also decreases gradually, thereby reducing the temperature of the device. As the temperature decreases, due to the decrease in the resistance value of the eleventh resistor R11, the voltage at the first input terminal of the comparator CM1 also decreases. closure. Then, the power supply terminal VCC starts to charge the second capacitor C2 through the seventh resistor R7, the voltage of the second input terminal of the first amplifier AM1 increases, and the current IQ3 passing through the third transistor Q3 also starts to increase. In one embodiment, the comparator CM1 can be a hysteresis comparator.

FIG. 7 shows a temperature regulation curve according to the embodiment of the zero voltage switching circuit including the protection circuit 500, wherein the horizontal axis is time (T), and the vertical axis is current (I). In Figure 7,

IC2＝VC2/(A*R9) (3)

Where VC2 is the voltage on the second capacitor C2. Assume that when the system is working normally, the current of the third transistor Q3 is less than the maximum current of the system (that is, the system current does not reach the maximum, VC2<VREF, IC2<VREF/(A*R9)). Assuming that the temperature of the device continues to rise due to the large load current at this time, at time T1, the temperature of the device reaches the set temperature, the discharge path DS starts to discharge the second capacitor C2, and the voltage VC2 on the second capacitor C2 starts to decrease. Since the device is not working at full load, that is, the maximum value of the current IQ3 of the third transistor Q3 has not reached the maximum, from T1 to T2, although the voltage VC2 on the second capacitor C2 gradually decreases, the current IQ3 on the third transistor Q3 does not decrease. . From time T2, the voltage on the second capacitor C2 drops to a sufficiently small value, the current IQ3 on the third transistor Q3 starts to drop along with the voltage VC2 of the second capacitor C2, and the system temperature starts to drop. At time T3, the system temperature will reach a sufficiently low level, the comparator CM1 will switch to a low level, the discharge path DS will stop discharging the second capacitor C2, the power supply terminal VCC will start to charge the second capacitor C2 through the seventh resistor R7, and the amplifier AM1 will The voltage at the first terminal rises, and the current IQ3 passing through the third transistor Q3 also starts to rise. At time T4, the current IQ3 passing through Q3 starts to recover to the normal level. At time T5, the voltage VC2 of the second capacitor C2 recovers to the maximum voltage VREF. It should be noted that, because the discharge path DS and the seventh resistor R7 charge and discharge the second capacitor C2 at different rates, the falling and rising rates of the current IQ3 on the third crystal Q3 may also be inconsistent.

It can be seen from FIG. 7 that the protection circuit 500 shown in FIG. 6 can make the temperature change smoothly within a certain range, instead of frequent switching on and off or hot and cold. Therefore, those skilled in the art can reasonably set the ratio of the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12, and the thirteenth resistor R13 to charge and discharge the second capacitor C2, and then the device The temperature is stabilized within a certain range to achieve the purpose of constant temperature. For example, it is stable between 280 and 300 degrees.

It should be pointed out that those skilled in the art can reasonably set the resistance value, ratio and temperature characteristics of the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12 and the thirteenth resistor R13 according to the teaching of the present invention. To accomplish the purpose of the present invention, for example, the temperature coefficient of the tenth resistor R10 is lower than the temperature coefficient of the twelfth resistor R12, instead of setting the eleventh resistor R11 to a temperature coefficient higher than that of the thirteenth resistor R11 as described in the embodiment. Resistor R13. These all do not depart from the protection scope of the present invention.

The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, and any new method or process step or any new combination disclosed. Any insubstantial changes or improvements made by those skilled in the art without departing from the spirit of the present invention shall all fall within the protection scope of the claims of the present invention.

Claims (6)

1. A plane transfer device is characterized by comprising an upper table top, a lower table top, a movable supporting rod, a first high-frequency oscillating circuit, a second high-frequency oscillating circuit, a protection circuit and a supporting table, wherein the upper table top is arranged on the supporting table, the upper table top and the lower table top are arranged in parallel, the upper table top and the lower table top are connected through the movable supporting rod, the upper table top and the lower table top are overlapped with each other when being pressed, the first high-frequency oscillating circuit and the second high-frequency oscillating circuit are arranged in the supporting table, a first resonant coil of the first high-frequency oscillating circuit is arranged on the lower table top, a second resonant coil of the second high-frequency oscillating circuit is arranged on the upper table top, and the first resonant coil and the second resonant coil are overlapped when the upper table top and the lower table top are pressed;

the first high-frequency oscillating circuit and the second high-frequency oscillating circuit both adopt zero-voltage switching circuits;

the zero-voltage switch circuit comprises a power supply, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a first high-frequency coil, a first transistor, a second transistor, a third diode, a fourth diode, a first diode, a sixth diode, a second inductor and a third inductor; the first end of the first resistor is connected with the first end of the second inductor, the first end of the fourth resistor and the positive electrode of a power supply, the second end of the first resistor is connected with the first end of the second resistor, the second end of the first diode, the first end of the third diode and the G electrode of the first transistor, the second end of the second inductor is connected with the first end of the first high-frequency coil and the first end of the third inductor, the second end of the fourth resistor is connected with the second end of the third resistor, the first end of the sixth diode, the second end of the fourth diode and the G electrode of the second transistor, the first end of the first diode is connected with the first end of the third inductor, the second end of the first capacitor, the second end of the first high-frequency coil and the D pole of the second transistor, the second end of the sixth diode is connected with the lower end of the second inductor, the first end of the first capacitor, the first end of the first high-frequency coil and the D pole of the first transistor, the second end of the second resistor, the second end of the third diode, the S pole of the first transistor, the second end of the second diode, the first end of the third resistor, the first end of the fourth diode, the S pole of the second transistor and the first end of the fifth diode are connected to a power ground, wherein the second inductor and the third inductor are freewheeling inductors, and the first high-frequency coil is a resonant coil;

the protection circuit is coupled between a power supply terminal and a first terminal of a second inductor, and comprises a reference voltage generation circuit and a feedback loop, wherein the reference voltage generation circuit comprises a parallel circuit and a seventh resistor, the parallel circuit comprises a seventh zener diode, an eighth resistor and a second capacitor which are connected in parallel, the first terminal of the parallel circuit is grounded, the second terminal of the parallel circuit is coupled to the first terminal of the seventh resistor, the second terminal of the seventh resistor is coupled to the power supply terminal, the feedback loop comprises a third transistor, a first amplifier, a second amplifier and a ninth resistor, the first terminal of the third transistor is coupled to the power supply terminal, the second terminal of the third transistor is coupled to the first terminal of a first high-frequency coil, the control terminal of the third transistor is coupled to the output terminal of the first amplifier, the second input terminal of the first amplifier is coupled to the second terminal of the parallel circuit, the first input terminal of the first amplifier is coupled to the output terminal of the second amplifier, the input terminal of the second amplifier is coupled to the first terminal of the first high-frequency coil, the output terminal of the second amplifier is coupled to the ninth resistor and then coupled to the ground, and the third amplifier is a field effect transistor or a triode;

the protection circuit further comprises a resistor network, a comparator and a discharge path, wherein the resistor network comprises a tenth resistor, an eleventh resistor, a twelfth resistor and a thirteenth resistor, a first end of the tenth resistor is coupled to the power supply terminal, a second end of the tenth resistor is coupled to the ground after being coupled to the eleventh resistor, a first end of the twelfth resistor is coupled to the power supply terminal, a second end of the twelfth resistor is coupled to the ground after being coupled to the thirteenth resistor, a second end of the tenth resistor is coupled to a first input terminal of the comparator, a second end of the twelfth resistor is coupled to a second input terminal of the comparator, the discharge path comprises an N-MOS transistor and a fourteenth resistor which are connected in series, an output terminal of the comparator is connected to a control terminal of the N-MOS transistor, a second terminal of the N-MOS transistor is coupled to the ground, a first terminal of the N-MOS transistor is coupled to the first terminal of the fourteenth resistor, and a second terminal of the fourteenth resistor is coupled to the second input terminal of the first amplifier.

2. The flat transfer device according to claim 1, wherein the movable support rods comprise a first support shaft, a second support shaft, a third support shaft and a fourth support shaft which are parallel to each other, the first support shaft, the second support shaft, the third support shaft and the fourth support shaft are connected to opposite sides of the upper table top and the lower table top, and the first support shaft, the second support shaft, the third support shaft and the fourth support shaft are perpendicular to the upper table top when the upper table top and the lower table top are most distant.

3. The apparatus for transferring a flat surface according to claim 2, wherein one end of each of the first and second support shafts is hinged to one end of each of two opposite sides of the upper table top, the other end of each of the first and second support shafts is hinged to a non-end of each of two opposite sides of the lower table top, one end of each of the third and fourth support shafts is hinged to a non-end of each of two opposite sides of the upper table top, the other end of each of the third and fourth support shafts is hinged to one end of each of two opposite sides of the lower table top, and the first, second, third and fourth support shafts are movable within 90 ° along a hinge point at the hinge point.

4. The flat transfer device according to claim 1, wherein the upper surface of the lower table has a first groove in which the first resonance coil is disposed, and the lower surface of the upper table has a second groove in which the second resonance coil is disposed.

5. The plane transfer apparatus according to claim 1, wherein the first resonance coil and the second resonance coil are adhered to an upper surface of the lower stage and a lower surface of the upper stage, respectively.

6. The flat transfer device according to claim 1, wherein the tenth resistor and the twelfth resistor are matched resistors, the eleventh resistor has a temperature coefficient larger than that of the thirteenth resistor, and the eleventh resistor has a resistance value smaller than that of the thirteenth resistor at normal temperature.

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