Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

125VDC Substation Battery Simulator

125VDC Substation Battery Simulator

125VDC Substation Battery Simulator

I'm looking for either a ready made device or something simple for one of our test racks and a few other applications. The primary use would be powering logic (opto isolated) inputs on protection relays, PLC's and similar. Most of our SEL devices have a universal power supply input, so I'll use AC for the larger loads. We have the SEL power supply unit, however this gets used in the field often and my intention is to keep something permanent with the test rack. The SEL has 2 125 VDC outputs, but they are not very well regulated. I can find all kinds of 48V / 24V supplies, just can't seem to find a reasonably priced 125V unit. I'm thinking 2A max, or less would be fine.

I put together a small unit using a boost converter, which is OK for now, but was wondering if there is something better out there with built in protection, etc.

RE: 125VDC Substation Battery Simulator

I found a $50 solution on Ebay. An Electrophoresis Power Supply is used in medical work. Used units are quite inexpensive. My unit goes up to 300W / 2kV.

I found the trick is hanging a 1 Mohm resistor in parallel with the output, else the unit won't start up.

I'll continue to power the various relays (SEL with universal AC/DC) with line voltage. This supply is for wetting logic inputs.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close