Capacitive Weed Control Device Using Pulsed High Voltage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for electrical weed control are inefficient, expensive, and cause collateral damage to the environment, as they require high energy consumption and can only superficially damage weeds, leading to repeated treatments and thermal damage.

Innovation Solution

A device that uses a low-voltage electrical power supply to generate high-voltage pulses through a step-up circuit and a capacitively acting electrical storage element, with a pulse shaper to deliver defined high-frequency discharges to weeds via an applicator, minimizing energy consumption and environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high voltage is applied continuously or with prolonged exposure time to destroy weeds, then the weeds are damaged, but the energy consumption increases and the device becomes expensive and unwieldy

Engineering Contradiction:
Improveweed destruction effectivenessVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic pulsed high voltage instead of continuous application. The control unit switches the high voltage on and off in pulses, delivering the necessary electrical energy to destroy weed cells while minimizing overall energy consumption. This pulsed action allows the capacitive element to recharge between pulses, maintaining effectiveness while reducing power requirements.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent uses short-duration high-voltage pulses that rapidly deliver the required energy dose to the weeds. The high voltage is applied in brief bursts sufficient to cause immediate cell membrane breakdown and plant death, then switched off. This 'rushing through' approach achieves weed destruction without the prolonged exposure that would waste energy and require larger, more expensive power supplies.

Inventive Principle:
Principle #21Skipping (Rushing through)

2Reliability

If electrical power is increased to achieve effective weed control, then weeds are destroyed, but the device becomes expensive and unwieldy

Engineering Contradiction:
Improveweed destruction effectivenessVSAvoiddevice size and cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

By using pulsed high voltage rather than continuous high power, the device can use smaller, less expensive capacitive elements and power supplies. The capacitive element charges to high voltage during the off-period and discharges in brief pulses during the on-period, achieving effective weed control with components that would be too large and expensive for continuous operation at the same energy level.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent employs a dynamically switching system where the high voltage is alternately connected to and disconnected from the weeds. The control unit dynamically switches the connection state, allowing the capacitive element to charge and discharge repeatedly. This dynamic operation enables the use of smaller energy storage components compared to static continuous high-power systems.

Inventive Principle:
Principle #15Dynamics

3Reliability

If thermal methods are used to destroy weeds, then weeds are killed, but the entire environment is heated causing collateral damage

Engineering Contradiction:
Improveweed destruction effectivenessVSAvoidenvironmental damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces thermal mechanisms with electrical mechanisms for weed destruction. Instead of heating the environment thermally (which would damage surrounding plants and soil), the system uses direct electrical pulses that cause cell membrane breakdown through electropermeabilization. This substitution of the action mechanism achieves selective weed destruction without the collateral thermal damage to the broader environment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The electrical pulses are applied locally to the weeds through electrodes in close proximity to the plant material. The high voltage effect is concentrated at the application point where the electrical field directly contacts the weed cells, causing localized cell membrane disruption. This local application prevents the widespread environmental heating that would occur with thermal methods, as the electrical energy is deposited directly into the target tissue rather than being distributed as heat throughout the environment.

Inventive Principle:
Principle #3Local quality

4Use of energy by moving object

If existing electrical weed control methods are used, then some weed damage is achieved, but the damage is superficial and weeds sprout again

Engineering Contradiction:
Improveenergy efficiencyVSAvoidpermanent weed destruction
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent uses high-voltage pulses with parameters specifically optimized for complete plant destruction. The voltage level, pulse duration, and repetition rate are controlled to deliver sufficient energy to break down cell membranes throughout the entire plant, including roots. This parameter optimization ensures that the electrical energy causes irreversible damage to all plant tissues, preventing regrowth while maintaining energy efficiency by avoiding excessive or prolonged application.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces insufficient electrical methods with high-voltage pulsed electrical discharge that causes immediate and complete cell membrane breakdown. The high voltage creates electrical fields strong enough to puncture and destroy cell membranes throughout the plant structure, ensuring complete mortality rather than the superficial damage that allows regrowth. This substitution of the electrical mechanism with properly parameterized high-voltage pulses achieves permanent destruction while remaining energy-efficient.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 device effectively and permanently damages weeds with short, strong electrical impulses, reducing the need for repeated treatments and minimizing environmental damage, while being compact, portable, and cost-effective.

Implementation Method 1

a capacitively acting electrical component, in particular a capacitor, for buffering the high voltage

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

high-voltage pulses are transmitted to the undesired ground vegetation... the high voltage is discharged in a defined minimum voltage and with high-frequency components

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Implementation Method 3

high-voltage pulses are transmitted to the undesired ground vegetation... with a defined minimum voltage and with high-frequency components

Methodology Applied
Scientific EffectElectrical discharge: Electrostatic Discharge

Data Source

PatentEP3415004B1Weed control
Publication Date: 2021.10.20 BIRCHMEIER SPRUHTECHN
  • EP3415004B1 patent drawingFigure 1~2
  • EP3415004B1 patent drawingFigure 3a~3d
  • EP3415004B1 patent drawingFigure 4a~4b

AI summary

The invention relates to a device (1) for controlling unwanted ground vegetation (29) comprising an electrical power supply (40) for providing a supply voltage (41) in the low-voltage range, an electrical boost circuit (42) for providing a high voltage (43) from the supply voltage (41), and at least one applicator (10) for transmitting high-voltage pulses to the unwanted ground vegetation (29). According to the invention, a capacitive electrical storage element (44) for the high voltage (43) is arranged in the electrical path to the applicator (10), as well as a pulse shaper (46) in the electrical path between the storage element (44) and at least one application electrode (27) of the applicator (10).