DESC:FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. TITLE OF THE INVENTION: “An Overload Protection Device For ZVS Frequency Generator”
2. APPLICANTS:

(a) Name : Weismacher Eco Private Limited
(b) Nationality : Indian
(c) Address : Mezzanine Floor, M/2, N.R.House
Near Popular House, Ashram Road
Ahmedabad 380 009, Gujarat, India.

PROVISIONAL

The following specification describes the invention. þ COMPLETE

The following specification particularly describes the invention and the manner in which it is to be performed.

Field of invention

The present invention relates to an overload protection device, and in particular it relates to an overload protection device for preventing overheating and potential harm to a Zero-Voltage-Switching (ZVS) generator.

Background of invention

In today’s era, advances in resonant and quasi-resonant power conversion technology propose alternative solutions to a conflicting set of square wave conversion design goals; obtaining high efficiency operation at a high switching frequency from a high voltage source. Currently, the conventional approaches are by far, still in the production mainstream. However, an increasing challenge can be witnessed by the emerging resonant technologies, primarily due to their lossless switching merits.

The concept of quasi-resonant, “lossless” switching is not new, numerous efforts focusing on zero current switching ensued, first perceived as the candidate for tomorrow’s generation of high frequency power converters. Such beliefs impeded the quest for high efficiency operation with high voltage inputs, these beliefs were avoided by implementing a zero voltage switching technique. The technique of zero voltage switching is applicable to all switching topologies; the buck regulator and its derivatives (forward, half and full bridge), the flyback, and boost converters etc.

Zero voltage switching can best be defined as conventional square wave power conversion during the switch’s on-time with “resonant” switching transitions. For the most part, it can be considered as square wave power utilizing a constant off-time control which varies the conversion frequency, or on-time to maintain regulation of the output voltage. A flyback transformer can be defined as an energy conversion device that transfers energy from one part of the circuit to the other part at constant power. In a flyback transformer, the voltage is stepped up to a very high value based on the application. It is also called a line output transformer, as the output line voltage is fed to the other part of the circuit. However, output voltage is a formed arc, which is of very high voltage in the case of flyback transformers. This output voltage cannot be transmitted to long distances, but can only use for specific applications like SMPS or CRT tube. The core of the flyback transformer is similar to the conventional transformer but is compact in size.

The flyback converters suffer from power losses when switching transitions occur with non-zero voltages across the power switches. Thus, zero voltage switching (ZVS) has been implemented in flyback converters to accomplish switching at zero voltage so as to achieve high efficiencies. Various techniques for implementing zero voltage switching have been known variable frequency (VF) ZVS DCM operation mode that can be implemented in the flyback converter in a VF ZVS DCM operation mode. However, with the use of the extended SR conduction period, the switching
frequency of the flyback converter becomes variable as a function of the load regulation. Variable frequency operation is undesirable, especially when avoidance of electromagnetic interference (EMI) disturbance is important.

Another technique of using zero voltage switching (ZVS) piezoelectric driving circuit, the piezoelectric transformer has been used extensively in the power driving circuits. However, the piezoelectric transformer still has insurmountable problems. Moreover, by not including an inductor in a piezoelectric transformer driving circuit, though it can achieve Zero voltage Switching (ZVS) for a specific load range, yet the frequency range applicable is just too narrow, so that the piezoelectric transformer is not able to keep up ZVS operations under the conditions of frequency variation feedback control and large range load variations. For this reason, the development and application of piezoelectric transformer in power supply is rather limited.

While there are different techniques reported which generally require many extra active/passive circuits. In particular, extra active circuits highly deteriorate the reliability of the system due to the additional complexity imposed by the active components. Also, the effectiveness of these techniques are questionable.

When the ZVS circuit is not connected to a coil, it is considered to be without load. In this state, all the power is dissipated in the inductors and MOSFETs, resulting in a high current flow that can potentially damage the board.

Hence, the need exists for a device to protect zero-voltage-switching (ZVS) circuit from overload.

Object of invention

The main object of the present invention is to provide a device that detects the high current and sends a signal to the microcontroller unit which then cuts off the main power supply.

Another object of the present invention is to provide a device that prevents the high current flow in the circuit due to the power dissipated in the inductors and MOSFETs that can potentially damage the components and board due to overheating.

Summary of invention

The present invention relates to a device which includes a ZVS circuit, which stands for Zero Voltage Switching. The ZVS Induction Heating Board with a Fly back Driver is a compact and efficient device that is commonly used for induction heating applications. It works by converting input power, typically DC, into a high-frequency AC signal. The flyback driver utilizes a transformer to increase voltage and create a high-frequency oscillation. This high-frequency current flowing through the coil generates a magnetic field that is utilized for water treatment.
When the ZVS circuit is not connected to a coil, it is considered to be without load. In this state, all the power is dissipated in the inductors and MOSFETs, resulting in a high current flow that can potentially damage the board.
To prevent this damage caused by high current flow, a current sensor is used in conjunction with a microcontroller unit for protection. When the high frequency generator is operating without a load attached, the current sensor detects the high current and sends a signal to the microcontroller unit. The microcontroller unit then cuts off the main power supply to prevent any potential harm.

Brief description of drawings

Objects and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying figure of the drawing wherein:

Fig. 1 illustrates a schematic view of the device with ZVS frequency generator and microcontroller unit in conjunction with current sensor.

Detailed description of invention
The nature of the invention and the manner in which it works is clearly described in the complete specification. The invention has various embodiments and they are clearly described in the following pages of the complete specification. Before explaining the present invention, it is to be understood that the invention is not limited in its application.

Now as shown in Fig. 1, a proposed device according to present invention is electrically connected to the ZVS frequency generator (1) at input end thereof. Said ZVS frequency generator (1) is loaded with, but not limited to, a coil (4) at output end.

Referring continuous with Fig. 1, the power is supplied to the ZVS frequency generator (1) after passing through the protection device according to present invention. Said protection device comprises a current sensor (3) that detects high current flowing to the ZVS frequency generator and sends signal to a microcontroller unit (2). Said microcontroller unit (2), upon receiving signal from the current sensor (3), cuts off the main power supply.

In operation, when the ZVS high frequency generator (1) is not connected to a coil (4), it is considered to be without load. In this state, all the power is dissipated in the inductors and MOSFETs, resulting in a high current flow that can potentially damage the board. To prevent this damage caused by high current flow, a current sensor (3) is used in conjunction with a microcontroller unit (2) for protection. When the high frequency generator is operating without a load attached, the current sensor (3) detects the high current and sends a signal to the microcontroller unit (2). The microcontroller unit (2) then cuts off the main power supply by tripping the relay (5) to prevent any potential harm.

The invention has been described with reference to specific embodiment which is merely illustrative and not intended to limit the scope of the invention as defined in the complete specification.

Reference numerals :
ZVS frequency generator (1)
microcontroller unit (2)
current sensor (3)
coil (4)
relay (5)
,CLAIMS:We Claim:
1. An overload protection device for ZVS frequency generator comprising :
a ZVS frequency generator (1) coupled to a coil (4) at the output end;
characterized in that
a microcontroller unit (2) and a current sensor (3) is electrically connected to an input end of the ZVS frequency generator (1);
wherein, the current sensor (3) is configured to detect flow of current supplied to the ZVS frequency generator (1);
said current sensor (3) sends signal to the micro controller unit (2) to cut off power supply on detecting the ZVS frequency generator (1) with no load.
2. The overload protection device for ZVS frequency generator as claimed in claim 1, wherein the microcontroller unit (2) on receiving the signal from the current sensor (3) cuts off power supplies to avoid to the ZVS frequency generator (1) by tripping a relay.
3. A method for functioning of an overload protection device for ZVS frequency generator comprising:
a. Sensing a current through a current sensor (3) flowing to a ZVS frequency generator (1);
b. Sending a signal by the current sensor (3) to a microcontroller unit (2) if detecting high current flowing to the ZVS frequency generator (1);
c. Receiving the signal by the microcontroller unit (2) and tripping of a relay by the microcontroller unit (2) to cut off power supply.

Dated this on 8th January, 2025.

Dr. Omkar Rajeshkumar Acharya
Advocates & Patent Agent
For and on Behalf of Applicant
IN/PA - 4341