Designed for multiple sized dogs, the leash features an ergonomically designed handle that allows the pet’s best friend to have a comfortable grip with a quick locking brake to stop the recoil of the leash when desired.
Pet owners everywhere rejoice as dog leash lights the way on dark nights.
Goddard Technologies (GTI), a product design and development firm for medical, consumer, industrial and military products, worked with Fido Fashions to develop a patented self-power generating dog leash.
Designed for multiple sized dogs, the leash features an ergonomically designed handle that allows the pet’s best friend to have a comfortable grip with a quick locking brake to stop the recoil of the leash when desired.
The leash comes equipped with three high intensity LEDs to light the way and a safety button with an emergency tone in case trouble is afoot.
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This leash is patented to generate all of its LED light and emergency tone power by utilizing the coil and recoil of the leash cord within the case.
The team at GTI was involved in the creation of the power generating dog leash in the very early stages of its development. GTI faced many design challenges, including creating the correct charging levels when a either a small dog or large dog were being walked. The coil rates for the mechanisms were critical to a properly designed charge circuit.
Through a phased program of working units and volumetric prototypes, GTI was able to create a stable and robust design for the leash while
In PD&D’s latest Inside Design interview, Andrew Goddard, president and owner of GTI discusses his crucial role in the design and development of Fido Fashions’ Power-Generating Dog Leash.
PD&D: How does the leash work? 
Andrew Goddard: The product is basically no different than most other adjustable coil type dog leashes on the market. What our client did was conceive of a patented way of generating power from the energy developed be the dog pulling the leash out and then by the recoil when the dog comes to heel. The patented design has a primary gear train mechanism designed to spin a power generator when the leash hub is spun in and out.
PD&D: What harvests the energy? How is it stored?
Goddard: A custom designed electronics set takes the energy that is developed from the generator and applies it towards charging appropriately-sized lithium-ion rechargeable batteries.
As the rates of coil and recoil between large, medium and small dogs were completely variable, the charge circuit had to have internal protections built in so that there would be natural cutoffs from an overcharging state.
Conversely, the electronics also had a low voltage cutoff for when the batteries could not provide adequate voltage to the LEDs, saving the product from a deep discharge of the batteries requiring increased numbers of coil/recoil cycles to bring the batteries back to a full charge state.
PD&D: What type of LEDs were used?
Goddard: The LEDs in the assembly were high brightness, low power consumption, directionally focused LEDs from a major manufacturer.
PD&D: What is the internal power supply?
Goddard: A transformer/generator spins when the leash hub assembly rotates, charging all of the batteries, which in turn powers the LEDs.
PD&D: How long will the LEDs be powered without recharge?
Goddard: The LEDs could run for six hours or more from a fully charged battery. However, it would run for two-to-three hours to reach the low voltage cutoff level.
PD&D: What were your biggest challenges throughout the product development? How did you overcome them?
Goddard: The three biggest challenges were:
- Properly designing the recharge circuit.
- Properly sizing the recoil spring for the leash to smoothly recoil into the casing.
- Minimizing the effect of the pull out force when the generator is under load from charging increasing the leash pull out force for smaller dogs.
All of these areas were an intense focus for engineering activity throughout the program.
We were able to handle these issues through a combination of developing bench top working models to understand all of the performance related issues, designing a proper gear train with the correct spin ratio to optimize charge rates, iterating on coil springs and their stiffness and then changing battery topology from nickel metal hydride (NIMH) to lithium ion (li-on) for better battery life and use.
PD&D: What were you able to do differently by becoming involved with the project early?
Goddard: By being involved early on with this product, we were able to understand more about where the client and product needed to be positioned and what features were most important.
We quickly realized the most challenging feature was the charge circuit and we focused a great deal of effort in that area to get them longest battery life with minimal coil/recoil of the leash.
For more information, please visit www.goddardtech.com & www.fido-fashion.com.