Heating circuit of gutta-percha filling instrument

Abstract

The utility model provides a gutta-percha filling instrument heating circuit which comprises a current-limiting resistor, a capacitor, a change-over switch, a heating load and an MOS tube, one end of the heating load is connected with a fixed port of the change-over switch, a first change-over port of the change-over switch is connected with a battery power supply end, and a second change-over port of the change-over switch is connected with a positive electrode of the capacitor; the anode of the capacitor is connected with the battery power supply end through the current-limiting resistor, and the cathode of the capacitor is connected with the grounding end; the other end of the heating load is connected with the drain electrode of the MOS tube, the source electrode of the MOS tube is connected with the grounding end, and the grid electrode of the MOS tube is connected with the control end. According to the heating circuit of the gutta-percha filling instrument provided by the utility model, the heating current is not limited by the internal resistance of the battery, large-current discharge of the battery is avoided, and the service life of the battery is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model belongs to heating circuit technical field, specifically, relate to a kind of gutta percha filling instrument heating circuit. BACKGROUND

[0002] The existing gutta percha filling instrument directly heats using lithium battery, but is limited by battery internal resistance, cannot obtain larger heating current, and heating speed is slow.Moreover, frequent large current heating can seriously reduce the service life of lithium battery, leading to short equipment maintenance period, high failure rate, and then leading to high after-sales cost. SUMMARY

[0003] The utility model provides a kind of gutta percha filling instrument heating circuit for the above-mentioned deficiencies, heating current is not limited by battery internal resistance, avoid the large current discharge of battery, prolong the service life of battery.

[0004] To solve the above technical problems, the utility model embodiment adopts the following technical scheme:

[0005] The utility model embodiment provides a kind of gutta percha filling instrument heating circuit, including current-limiting resistance, capacitor, switching switch, heating load and MOS tube, one end of the heating load is connected with the fixed port of switching switch, the first switching port of switching switch is connected with battery power supply end, and the second switching port of switching switch is connected with the anode of capacitor;The anode of capacitor is connected with battery power supply end by current-limiting resistance, and the cathode of capacitor is connected with ground terminal;The other end of heating load is connected with the drain of MOS tube, the source of MOS tube is connected with ground terminal, and the gate of MOS tube is connected with control end.

[0006] As a further improvement of the utility model embodiment, the capacitor is super capacitor.

[0007] As a further improvement of the utility model embodiment, the MOS tube is N-channel MOS tube.

[0008] As a further improvement of the utility model embodiment, pull-down resistance is connected between the gate and the source of the MOS tube.

[0009] As a further improvement of the utility model embodiment, the control end inputs PWM signal.

[0010] Compared with the prior art, the technical scheme of the utility model has the following beneficial effects:

[0011] The utility model provides a kind of gutta percha filling instrument heating circuit, uses super capacitor to obtain large current and heat, uses battery to obtain small current and keep temperature, and the maximum heating current is no longer limited by battery internal resistance, avoids the large current discharge of battery, greatly prolongs the service life of battery, and reduces after-sales maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of a heating circuit of a gutta-percha filling instrument according to an embodiment of the present invention.

[0013] Description of main component symbols

[0014] Battery power supply terminal VBAT

[0015] Control

[0016] MOS tube Q1

[0017] Capacitor C1

[0018] Current limiting resistor R1

[0019] Heating load Z1

[0020] Pull-down resistor R3

[0021] Switch S1

[0022] Ground terminal GND DETAILED DESCRIPTION

[0023] The technical solution of the present utility model is described in detail below with reference to the accompanying drawings.

[0024] The present invention provides a heating circuit for a gutta-percha filling instrument. Figure 1 As shown, it includes a current-limiting resistor R1, a capacitor C1, a switching switch S1, a heating load Z1, and a MOS transistor Q1. One end of the heating load Z1 is connected to the fixed port of the switching switch S1, the first switching port of the switching switch S1 is connected to the battery power supply terminal VBAT, and the second switching port of the switching switch S1 is connected to the positive electrode of the capacitor C1. The positive electrode of the capacitor C1 is connected to the battery power supply terminal VBAT through the current-limiting resistor R1, and the negative electrode of the capacitor C1 is connected to the ground terminal GND. The other end of the heating load Z1 is connected to the drain of the MOS transistor Q1, the source of the MOS transistor Q1 is connected to the ground terminal GND, and the gate of the MOS transistor Q1 is connected to the control terminal Control.

[0025] In this embodiment, the battery power supply terminal VBAT is used to connect to a lithium battery. Capacitor C1 is a supercapacitor used to provide high current for rapid heating. Current-limiting resistor R1 is used to limit the maximum charging current of capacitor C1. MOS transistor Q1 is an N-channel MOS transistor. A pull-down resistor R3 is connected between the gate and source of MOS transistor Q1 to accelerate the shutdown speed of MOS transistor Q1. The control terminal Control inputs a PWM signal.

[0026] The working process of the heating circuit of the gutta-percha filling instrument in the above embodiment is as follows:

[0027] After the start of the dental adhesive filling instrument, the lithium battery charges the capacitor C1 through the current-limiting resistor R1, and the voltage of the capacitor C1 rises. Start the heating function, the fixed port and the second switching port of the switching switch S1 are conductive. The capacitor C1 supplies power to the heating load Z1, and the control end Control sends a high duty ratio PWM signal to the MOS tube Q1, which controls the MOS tube Q1 and the pull-down resistor R3, so that the temperature of the heating load Z1 rises rapidly to the target temperature. After rising to the target temperature, the fixed port and the first switching port of the switching switch are conductive, and the lithium battery supplies power to the heating load Z1, and the control end Control sends a PWM signal with appropriate duty ratio to the MOS tube Q1, which controls the MOS tube Q1 and the pull-down resistor R3, so that the temperature of the heating load Z1 is maintained at the target temperature.

[0028] The dental adhesive filling instrument heating circuit of the embodiment uses supercapacitors to obtain large current for heating, and uses batteries to obtain small current for temperature maintenance, so that the maximum heating current is no longer limited by the internal resistance of the battery, the large current discharge of the battery is avoided, the service life of the battery is greatly prolonged, and the after-sales maintenance cost is reduced.

[0029] The basic principle, main features and advantages of the utility model are shown and described above. Those skilled in the art should understand that the utility model is not limited by the above specific embodiments, and the above specific embodiments and the description in the specification are only for further illustrating the principle of the utility model, and under the premise of not departing from the spirit and scope of the utility model, the utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the utility model claimed.

Claims

1. A heating circuit for a dental gutta-percha filling instrument, characterized in that, The current-limiting resistor, the capacitor, the switching switch, the heating load and the MOS tube are included, one end of the heating load is connected with a fixed port of the switching switch, a first switching port of the switching switch is connected with a battery power supply end, and a second switching port of the switching switch is connected with a positive electrode of the capacitor; the positive electrode of the capacitor is connected with the battery power supply end through the current-limiting resistor, and a negative electrode of the capacitor is connected with a grounding end; the other end of the heating load is connected with a drain electrode of the MOS tube, a source electrode of the MOS tube is connected with the grounding end, and a gate electrode of the MOS tube is connected with a control end.

2. The heating circuit for a dental gutta-percha filling instrument according to claim 1, wherein The capacitor is a super capacitor.

3. The heating circuit for a dental filling instrument according to claim 1, wherein The MOS tube is an N-channel MOS tube.

4. The heating circuit for a dental filling instrument according to claim 1, wherein A pull-down resistor is connected between the gate electrode and the source electrode of the MOS tube.

5. The heating circuit for a dental filling instrument of claim 1, wherein, The control end inputs a PWM signal.

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