People Have Said, "It's Like Pimp My Ride!"
I suppose that makes me UK agriculture’s version of Xzibit.
Ben Bryant – Precision Farming and Aftersales Manager, Chafer Machinery LTD
They say I was taking things apart before I could walk—but the key thing is, I could put them back together too.
Born on a farm on the Cambridgeshire/Hertfordshire borders, I grew up surrounded by agriculture. With the farm at home not being large enough to justify me staying on, I knew from a very young age that agricultural engineering was my future. I vividly remember watching a technician replace the clutch on one of Dad’s MF 698T tractors, and from then on, I was hooked.
I started my journey with an apprenticeship at a Case dealership, surrounded by experienced technicians who weren’t keen on electrics or Canbus systems. Determined to bridge that gap, I immersed myself in learning everything I could about emerging technologies. Fast forward 18 years, and I now lead the Aftersales Department at Chafer Machinery.
At Chafer, I oversee our fantastic team, supporting dealers and end-users. My passion for technology has been central to my journey. My first role here involved demonstrations and precision farming advice, which transitioned into my current dual role managing precision farming sales and product support for everything we manufacture and sell.
It’s been a rewarding journey, combining my love for agriculture with my passion for technology and problem-solving.
What is PWM? Brief Overview of PWM Rate Control
Pulse Width Modulation (PWM) rate control is a technology used in modern agricultural sprayers to precisely manage spray application rates. Instead of varying the pressure to adjust flow rates, PWM modulates the flow by rapidly turning nozzles on and off at a high frequency.
Here’s how it works:
Duty Cycle:
The system adjusts the "duty cycle," or the percentage of time the nozzle is open during each cycle.
A 50% duty cycle means the nozzle is open half the time and closed the other half.
A 100% duty cycle means the nozzle is fully open continuously.
Maintaining Constant Pressure:
By keeping the pressure constant and varying only the duty cycle, PWM ensures consistent droplet size regardless of flow rate changes. This improves application accuracy and minimizes drift.
Real-Time Adjustments:
PWM works in real-time, adjusting flow rates based on factors like sprayer speed or section control requirements. This ensures even application across the entire field, regardless of terrain or speed variations.
Precision and Efficiency:
PWM enables precise rate control for both uniform and variable-rate applications, reducing chemical waste, improving coverage, and enhancing environmental stewardship.
In summary, PWM rate control is a game-changing technology in agriculture, offering unparalleled precision, efficiency, and adaptability for modern spraying systems.
Why is PWM Necessary for Spot Spray Systems like Carbon Bee Smart Striker X?
Pulse Width Modulation (PWM) is essential for optimizing camera-based spot spray systems because it ensures precise, consistent, and efficient chemical application. Here’s why PWM is critical:
Precise Rate Control:
Camera systems detect weeds in real time. PWM adjusts flow rates instantly, applying the correct dose exactly where it’s needed.
Rapid Nozzle Activation/Deactivation:
PWM nozzles can cycle on and off rapidly to target specific areas, unlike slower systems such as Hypro ProStop or Arag Selectro, which can lag at high speeds, resulting in overspray or missed spots.
Consistent Pressure:
PWM maintains constant pressure while varying the duty cycle (time the nozzle is open), ensuring uniform droplet size and reducing drift.
Efficient Coverage:
It handles irregular target patterns seamlessly, delivering only what’s needed, where it’s needed.
Maximized ROI:
By minimizing waste and maximizing accuracy, PWM increases efficiency and reduces costs. In many cases, the system pays for itself in just a few seasons.
New or Retrofit My Existing Sprayer: What’s the Best Option?
The modern agricultural landscape is constantly evolving. Farmers need to maximize every bit of productive land, every piece of equipment, and every investment. So, when it comes to the choice between new equipment and retrofitting, there’s no one-size-fits-all answer.
With the availability of grants and incentives, such as the SFI (Sustainable Farming Incentive), the decision often comes down to the specific situation and goals of the operation. The good news is that almost any piece of kit can be retrofitted nowadays.
Over the past year, we’ve installed everything from simple boom levelling kits on sprayers that are 3–20 years old to comprehensive retrofits—including virtually everything but the kitchen sink—on sprayers over 25 years old. In more than one example, customers were able to recoup 60% of the cost through grant funding, making retrofitting an economically viable option.
As machinery grows larger and sees more intensive use, well-maintained older models are becoming harder to find, making preservation even more important. For example, while our larger machines might clock 2,000 hours annually on large-scale operations, we also serve customers who operate machines for just 250 hours a year, aiming to keep them in service for 10–20 years.
Ultimately, whether you choose new equipment or a retrofit, the best option depends on your specific circumstances and goals. With advancements in technology and financial incentives, both paths can offer significant benefits for the owner, operator, and, importantly, the environment.
Can PWM Be Retrofitted?
The short answer is yes. Most sprayers can be retrofitted with PWM, although systems with fully integrated electronics from manufacturers may require more complex installations. These systems may appear clunky but are entirely functional.
Common PWM Misconceptions
"It doesn’t work with air induction nozzles."
Incorrect. While not all air induction nozzles are compatible, there are options to achieve the desired droplet size with PWM.
"More Hz (faster cycling) is better."
False. Higher frequencies increase wear and tear, reduce maximum flow rates, and lead to inefficient "moving time" when the poppet is transitioning between on and off states.
"It’s hard to fix."
Not true—Raven Hawkeye systems, for example, are simpler to repair than older air shutoff systems. Intelligent components and straightforward diagnostics make servicing easy.
Why Trust Me?
I’m a "poacher turned gamekeeper"—I’ve worked in both sales and aftersales, so I understand the importance of reliability. After all, while sales teams may sell the first machine, aftersales teams sell the next one. At Chafer, we make sure the technology we sell won’t create headaches for the people who need to fix or operate it.
Overall, every advancement in technology benefits the farmer by making operations more efficient and, importantly, kinder to the environment. Farmers have evolved significantly over the last 50 years—from being just farmers to becoming custodians of the land and astute business professionals.
If you have any questions about PWM or precision farming technology, I’d be happy to help.