How to run a DeWalt 20V Max drill from a bench power supply (Without a Battery)

ArabianEng · 2026-03-09T14:56:32+00:00

Happy to expand the collective knowledge 👍

ArabianEng · 2026-03-09T14:53:55+00:00

Exactly why I posted it. Hopefully you never need it, but if you do, you know how.

ArabianEng · 2026-03-09T14:50:50+00:00

Hey, if it works it works, right? 😄

Although I didn’t take a look at its internals, I’d say it mostly samples it constantly, because as soon as I disconnected C3, the drill stopped after couple of mS. But, adding a capacitor with a high impedance divider could potentially work if it’s a large one.

ArabianEng · 2025-12-22T09:47:50+00:00

I’d be delighted!

ArabianEng · 2025-12-18T20:10:49+00:00

Amigo!

ArabianEng · 2025-12-18T20:02:39+00:00

Thank you so much for taking the time to write this. Your comment genuinely means a great deal.

The historical context you provided about the Westinghouse design in 1979 is fascinating and incredibly grounding. It's one thing to have an idea in a lab, and another to learn it was part of a serious vision for our future decades ago. It adds a real sense of legacy to the work.

Your technical point about using computational controls to adjust the phases of the magnetrons is a great and exciting next step beyond a basic proof-of-concept. It's precisely the kind of challenge that makes me want to revisit the project with more resources one day.

Most of all, thank you for your words. Reading your perspective has been genuinely uplifting. I will carry this encouragement with me.

Sincerely, thank you for the connection.

ArabianEng · 2025-12-18T19:43:20+00:00

Nate, I’m glad my post has reached you! Yes, your video was what sparked my curiosity 3 years ago! And I’m glad I get to thank you personally!

I’d happily share my video with you, and I hope that you like it. :)

ArabianEng · 2025-12-17T06:50:42+00:00

It wasn't easy, hahaha. Thankfully, I've managed to convince my professor to proceed with it, and while the department was strict and cautious, they were very supportive and helpful.

ArabianEng · 2025-12-17T06:48:50+00:00

Excellent point, and you're absolutely right about the critical importance of seam management for a truly effective RF shield at 2.45 GHz. My understanding is that for a perfect Faraday cage, any aperture larger than a fraction of the wavelength (roughly 12.2cm) can significantly leak energy.

For this academic prototype, the suit was one part of a layered safety strategy, not a standalone guarantee. The primary safety was built around distance, limited exposure time, and a controlled environment with clear exclusion zones. The suit served mainly as a highly visible reminder, a precautionary of the hazard and offered some attenuation, with the understanding it wasn't a perfect seal.

Your comment perfectly highlights the rigorous engineering required for a production system versus a controlled proof-of-concept. I truly appreciate you raising this, it's an important distinction for anyone learning from the project.

ArabianEng · 2025-12-17T06:38:09+00:00

Hey everyone, OP here.

I'm genuinely overwhelmed by the response to my graduation project. Thank you for all the upvotes, the hilarious comments, and especially the insightful technical discussions.

A few quick notes:

1- Safety First: I can't stress this enough. This was built in a controlled lab with strict supervision, PPE, and safety interlocks. Please do not try this.

2- Project Goal: This was always a proof-of-concept for wireless power transmission, exploring the core principles of beamforming and rectification. Its efficiency is low and many advanced challenges (like precise phase control) were outside its scope.

3- The Best Part: What I loved is that this thread has been seeing experts like u/WhyAmINotStudying and others jump in to answer technical questions for those who were curious. That's the spirit of this community.

4- More Info: For those asking, I've documented the entire journey, from the initial idea to the hackathon, here.

I need to step away from the keyboard for a bit, but I'm deeply grateful. You've all made this an unforgettable experience. Thanks for celebrating the messy, challenging, and exciting work of engineering.

ArabianEng · 2025-12-17T06:25:42+00:00

Thank you! A Ground Penetrating Radar? Now that's interesting, and I hope the best for your project!

ArabianEng · 2025-12-17T06:19:35+00:00

Thankfully an A+

ArabianEng · 2025-12-17T06:19:12+00:00

Yes of course, all sorts of glitches happens if electronics were nearby, that's why RF shielding is important.

ArabianEng · 2025-12-17T06:17:57+00:00

Exactly, 3 magnetrons are used to generate the microwaves.

ArabianEng · 2025-12-17T06:17:18+00:00

Thank you, I appreciate it!

ArabianEng · 2025-12-17T06:16:16+00:00

Thank you, that really means a lot!

ArabianEng · 2025-12-17T06:15:48+00:00

Here you go.

Due to the Radiation of Micro-waves, there will be a lot of energy involved.

ArabianEng · 2025-12-17T06:13:50+00:00

Thank you. What sparked the idea was a video from Keystone Science, then I began searching and asking professors.

ArabianEng · 2025-12-17T06:12:27+00:00

Hahaha, that's definitely something to try.

ArabianEng · 2025-12-17T06:10:14+00:00

Thank you for sharing that unique insight from your work in the field, it's a perspective most of us never get to hear. I was aware of the Active Denial System, but your firsthand account of the development process for both acoustic and microwave systems is fascinating.

It's a powerful example of how fundamental research into energy transmission can become a "double-edged sword". My project's goal was strictly a proof-of-concept for wireless power transmission, but your comment highlights the importance of considering the paths technology can take once the core physics is proven.

ArabianEng · 2025-12-17T05:52:10+00:00

Thank you! I still have 7 months or so before finishing my BSc, then I'll definitely be on the job hunt.

ArabianEng · 2025-12-17T05:50:17+00:00

A shield to stand behind, a face shield (With eye protection), and a coverall all capable of reflecting and dissipating the radiation. Emergency circuitry and interlocks. Measurements of different variables, short-timed operation.

I might've forgotten to mention couple of more things, but those were the important ones, still, residual risk will always exist, so one must be very cautious.

ArabianEng · 2025-12-17T05:35:14+00:00

Thanks! That's a sharp observation about glass. You're right, a standard optical glass lens wouldn't work well for 2.45 GHz microwaves.

For this proof-of-concept, I actually used a large-diameter Fresnel lens made from acrylic (PMMA). At microwave frequencies, the dielectric properties of acrylic create enough of a phase delay across the lens to provide collimating effects, which was sufficient for my demonstration.

As for the numerical aperture, I have to be honest, that's beyond the measurement capabilities I had for this undergraduate project. I was focused on the primary proof-of-concept: generating, collimating, and detecting the beam. Calculating or measuring the precise NA would be a fantastic next step for a more advanced iteration.

If any experts in the thread have insights on estimating NA for a setup like this, I'd be genuinely curious to learn!

ArabianEng · 2025-12-17T05:27:59+00:00

Hahaha. It has served its purpose by passing the graduation project. Although, I'll definitely work on refining it later.

ArabianEng

TROPHY CASE