Brushless heat gun provided with control circuit

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing heat guns have low electromagnetic compatibility (EMC), which fails to meet safety standards, posing security risks and performance issues.

Innovation Solution

A brushless heat gun with an integrated control circuit that includes a gear switch unit, EMC processing circuit, key module, detecting module, memory storage module, display module, and a drive circuit, featuring a discharging circuit, lightning protection circuit, and capacitors to enhance EMC and power management, along with a thermocouple temperature sensor for precise temperature control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional control circuits are used in heat guns, then the device can perform basic heating functions, but the electromagnetic compatibility is too low to pass safety standard tests

Engineering Contradiction:
ImproveEMC performanceVSAvoidelectromagnetic interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

An EMC processing circuit is introduced as an intermediary component between the power supply and the control circuit. This circuit includes common mode inductors, capacitors, and voltage regulators that filter and stabilize the power input, preventing electromagnetic interference from affecting the control system while maintaining proper device operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements protective measures in advance by incorporating surge protection circuits, voltage regulators, and EMI filters before the interference can affect the control system. These components cushion against voltage spikes and electromagnetic disturbances before they reach sensitive circuitry, ensuring compliance with safety standards.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Ease of operation

If multiple auxiliary circuits are added to improve overall circuit performance, then temperature control and display improve, but the circuit complexity increases

Engineering Contradiction:
Improvetemperature regulationVSAvoidcircuit complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The control circuit is designed with multi-functional components that perform multiple tasks. For example, the temperature sensor serves both measurement and control functions, while the microcontroller integrates temperature regulation, display control, and safety monitoring in a single unit, reducing overall circuit complexity while maintaining comprehensive functionality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Multiple auxiliary circuits are merged into an integrated control system. The temperature display circuit, power off time delay circuit, and zero-crossing detection circuit are combined with the main control unit, allowing these functions to share common components and reducing the total number of separate circuits needed.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution significantly improves EMC and security performance, ensuring the heat gun operates stably even with varying supply voltages and provides precise temperature control and display, enhancing overall safety and functionality.

Implementation Method 1

a discharging circuit connected with the external power supply

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a common mode inductor connected with the pre-capacitor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

The detecting module comprises at least one thermocouple temperature sensor disposed at the air outlet of a heating cylinder

Methodology Applied
Scientific EffectSeebeck effect: Seebeck Effect

Data Source

PatentEP3252391B1Brushless heat gun provided with control circuit
Publication Date: 2021.03.10 ZHEJIANG PRULDE ELECTRIC APPLIANCE CO LTD
  • EP3252391B1 patent drawingFigure 1~2

AI summary

The invention discloses a brushless heat gun provided with a control circuit, comprising: a fan module provided with a brushless motor and a heating module; a main control unit controlling the rotation of the fan module and the heating of the heating module; and a gear switch unit supplying power to the brushless heat gun, wherein an EMC processing circuit which used to enhance the electro magnetic compatibility of the brush heat gun is provided between the gear switch unit and an external power supply. A circuit with EMC processing capacity is provided so that the heat gun has better electro magnetic compatibility and higher security performance. The heat gun itself will not be significantly influenced when the supply voltage changes.