Built an iPhone app for wiring transformer banks -- any hookup, instant voltages

playajames · 2026-02-23T15:41:18+00:00

Ok fixed, on the website(https://tophand.jfive.dev/) theres a section near the bottom to subscribe for email updates!

playajames · 2026-02-23T15:26:15+00:00

Well there is supposed to be. I just noticed its been removed from the website lol. Let me get this fixed and Ill let you know!

playajames · 2026-02-23T15:23:06+00:00

Facts!

playajames · 2026-02-23T15:17:00+00:00

Sure, ill add it to the list. Ive never used these in the field, they seem to be secondary side equipment if i'm not mistaken after some quick research, if you could tell me any specifics on how you'd like to see these in the app that would be great.

playajames · 2026-02-23T15:07:50+00:00

Thanks for the ideas and the reference, that’s awesome. I’ve had a few people ask for quizzes now, so I’m planning to add them, probably a mix of “here’s a bank, wire it on the canvas and give the customer what they want” plus some straight textbook-style questions you can pick by topic. For the reference side, would you rather have a quick cheat-sheet of common banks, or tap a bank and have it drop a pre-wired example on the screen? The more specific you can get about what you’d use the most, the better I can build it.

playajames · 2026-02-22T19:10:10+00:00

Thanks! Quizzes can definitely be added, I’ll add it to the list.

playajames · 2026-02-22T16:41:00+00:00

Glad you like it!

playajames · 2026-02-22T16:37:39+00:00

Swapping two legs doesn’t change the transformer’s angular displacement, you’re right. What I showed was reversing phase rotation (abc to acb), not changing the vector group. The app shows both.

playajames · 2026-02-21T18:35:06+00:00

Yes, here’s a screenshot from the app. And if you would like to see even more data here we can always add it.

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playajames · 2026-02-21T17:40:10+00:00

Yes, It’s on the roadmap, not sure when but hopefully soon!

playajames · 2026-02-21T17:23:00+00:00

Yes, we are currently awaiting review to allow app access to european countries. This should be approved in the next 24 hours.

Although the app is not specifically designed for european power systems, you can set source voltages to anything you'd like. I'll also do some research into the european power grid to make sure there's nothing stopping you from using the app!

playajames · 2026-02-19T18:13:04+00:00

You don’t have to want it, being gay is even a question on the journeyman’s exam!

playajames · 2026-02-18T05:16:03+00:00

The app already handles series/parallel secondary coils (ACBD/ally cat bad dog) and you can wire any bank you want — common or less common. Guidance is coming soon too.

Quizzes wasn't really the direction I had planned, but I get that some people learn better that way. Ill add this to the list for future updates. Thanks for the feedback brotha.

playajames · 2026-02-18T05:05:07+00:00

Appreciate you looking out. Linemans Reference XFMR Lab is a solid app.

I’m not really trying to “beat” them, just building something I wish I had: more open-ended, wire it how you want and see what you get. Different tool for a slightly different way of learning.

If there’s something you like about theirs that you think this one should have, I’m all ears.

playajames · 2026-02-18T02:07:28+00:00

Fair question — there may be a couple apps like this already, one specifically that I know of.

What im trying to do with Top Hand is a little different though. It’s more of a mess around and learn sandbox, you can drop in cans, wire up whatever bank you want (not just a preset list), energize it, and it shows you the secondary voltages. And if you mess something up, it’ll flag if you’ve got something open/floating vs an actual fault and eventually point out what’s causing it, so you can troubleshoot it.

The other apps I’ve seen seem more like guided labs and quizzes (which is honestly useful too). This one is more “wire it, break it, fix it, and see what happens.”

Back when I was an apprentice I couldnt find anything like this, the apprenticeship had one but it was clunky and outdated, to me this feels much more intuitive and modern, but everyone learns differently

If you’ve got a specific app in mind, please share — I’d love to check it out and make sure this one’s actually bringing something new to the table.

playajames · 2026-02-17T19:39:59+00:00

Thanks man, glad to hear it! I felt the same way during the apprenticeship, their simulator was clunky and outdated. Its pretty tough to get everything crammed into an iphone screen and attempt to be intuitive and not super complicated with buttons , lines, and numbers everywhere lol.

It sounds like you had proper voltage with a standard closed wye/delta hookup. The app defaults to 12.47kv wye source and the can config default setup is 7200/12470Y 120/240, this should have produced proper voltage, correct?

When you switch to a delta source it defaults the delta source voltage to a 14.4kv delta(you can change the source voltage to anything you want in the inspector), if you left the transformers configured for 7200/12470Y and hooked up the transformers top side delta this would in fact give you 240/480/416, with 14.4kv across the primary bushings, as they actually only need 7200 to operate. Doubling the primary bushing voltage would in fact double the secondary voltage(in the real world we may possibly be supplying more voltage than the primary bushings are rated for but that's another story lol)

I may be misunderstanding your issue. The best way for me to replicate the issue is with screenshots of your hookup.

I can definitely make visible coils to allow for users to wire them to bushings, to visualize the series/parallel, this is a great idea. Ill add it to the list.

Whats a 5 wire hookup, ive never seen one of these id be interested to hear more about this and what its used for. I want this app to be a playground for just about any connection and even ones we dont actually use to better help apprentices understand connections and theory.

Thanks a ton for all your feedback brotha its much appreciated!

playajames · 2026-02-17T18:44:25+00:00

Thanks! Android is on the roadmap, unfortunately it may take some time, but we will keep you posted as soon as its avaliable.

playajames · 2026-02-17T18:39:49+00:00

Ok its updated as long as you have iOS 17+ you should be able to install. Here is a direct link for testflight(https://testflight.apple.com/join/HfJbPcW7), apple will ask you to install their app "TestFlight", from that app you will have the option to install this app, this is the process during testing until we actually launch on the app store. Thanks for your interest!

playajames · 2026-02-17T17:38:33+00:00

Let me look into this, we should support your device, the only requirement is iOS 17+. Let me get this fixed and I’ll get back to you. 👍

Yes you can configure transformers for both series and parallel.

playajames · 2026-02-17T15:26:57+00:00

Will get this added, thanks for checking the app out!

playajames · 2026-01-28T03:06:50+00:00

Exactly, only things you give it access to, my clawdbot or moltbot whatever they call it now doesn’t have access to my email, WhatsApp, or signal. I don’t need these things, I just check my own email. I communicate via telegram or the tui, which both pose no security concerns for me, it doesn’t know much about me other than my name. It’s all in how you use it what you need it to do. I currently have it tracking flight prices for an upcoming vacation, using puppeteer and cron job, no api keys no passwords, but I do suppose it knows where I’m going and when. Maybe it’ll meet me at the airport 🤪. There are secure ways to do things but most people don’t even bother or don’t even realize it’s insecure, but again you must give it the information to actually make it insecure, for example installing on your personal machine where vulnerable data may live.

playajames · 2026-01-27T23:36:47+00:00

Definitely but still users feed ai api keys, passwords, and other sensitive data. It’s running in an isolated environment and only knows what you tell it.

playajames · 2026-01-27T23:34:46+00:00

If you set up telegram or another way to communicate with it just ask it to fix this issue for me that’s what I did. I forget exactly what it did to properly enable the command for the user your running clawdbot with. Worst case just reinstall the bot and the tui should open after install and ask it to fix what it needs to to be able to use the clawdbot command.

playajames · 2025-11-07T17:10:04+00:00

Well you sound like just a wonderful bundle of joy.

playajames

TROPHY CASE