Substituting 12v AC/DC adapters SOLVED

I have a UniBrain Firewire 800 Hub. I have always used it and powered it from the computer’s firewire output. However, it provides the option of using an AC to DC adapter. The specs for the original adapter (which I do not have) are: Power Input Range: DC 8V - 30V, max. 1.35 A • I presume if I use an adapter it would take a little of the load off the computer (yes/no?). If so, can I use an adapter that is 12v but provided a different amp range… say, 2.0A or more? I have a few 12V adapters from older gear but I don’t know if I can substitute or it MUST be the same specs? Thank you

by dont-know-much
July 10, 2021

It is relatively unusual to have an input specification with a range of DC voltage, probably the device has its own voltage regulation sub circuit. The current is generally the maximum it can handle. As for the adaptor, its rated current is the maximum it can supply, so, in theory, you are OK. It is preferable to use one which is certified (ULx, CSA, etc.) for private use, and an obligation, at many places, if used "in public", even at an exposition, or as part of a demo, or something simiar.

by vanderghast
July 13, 2021

1 Answer

Answer by dont-know-much

thank you, vanderghast This was my first post on this site and didn't realize there was a reply to my question until a few moments ago. I thought I was suppose to receive an email notice that a reply had been posted. Oh! Well! No harm but did want to say thank you for weighing in. As for using the device in public... not likely. It is simply for an older firewire 800 hub in my little recording studio. I'm simply trying to still squeeze the last drops of use out of my old firewire gear as I move on to a new Mac with Thunderbolt 3 connections.

ACCEPTED +1 vote
by dont-know-much
July 14, 2021

Your Answer

You must log in or create an account (free!) to answer a question.

Log in Create an account


Go Ad-Free. Activate your CircuitLab membership. No more ads. Save unlimited circuits. Run unlimited simulations.

Search Questions & Answers


Ask a Question

Anyone can ask a question.

Did you already search (see above) to see if a similar question has already been answered? If you can't find the answer, you may ask a question.


About This Site

CircuitLab's Q&A site is a FREE questions and answers forum for electronics and electrical engineering students, hobbyists, and professionals.

We encourage you to use our built-in schematic & simulation software to add more detail to your questions and answers.

Acceptable Questions:

  • Concept or theory questions
  • Practical engineering questions
  • “Homework” questions
  • Software/hardware intersection
  • Best practices
  • Design choices & component selection
  • Troubleshooting

Unacceptable Questions:

  • Non-English language content
  • Non-question discussion
  • Non-electronics questions
  • Vendor-specific topics
  • Pure software questions
  • CircuitLab software support

Please respect that there are both seasoned experts and total newbies here: please be nice, be constructive, and be specific!

About CircuitLab

CircuitLab is an in-browser schematic capture and circuit simulation software tool to help you rapidly design and analyze analog and digital electronics systems.