×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Siemens Allis "Voltage Isolator"

Siemens Allis "Voltage Isolator"

Siemens Allis "Voltage Isolator"

(OP)
I came across this requirement from a Transit Authority customer looking to rebuild some old Siemens Allis electric railway substation gear. He has no record drawings unfortunately, and Siemens Services could not locate them by Serial Numbers so we have been forced to piecemeal this project together one part at a time. This one has me stymied.

They are calling it a "Voltage Isolator", I have attached a picture. I have no idea where it came from in the gear, their maintenance tech brought it in disambiguated. My guess is it is an old form of transducer. My hope is, someone here has seen something similar. Any help would be greatly appreciated.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln  
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies  

RE: Siemens Allis "Voltage Isolator"

Looks almost like DC-DC converter.  It may be to step DC voltage up or down for a different supply requirement, or it might be used to isolate and sectionalize one part of the control system.

You may have to shake a few wires to see where it is connected.  This is some of the "fun" stuff about messing around with old gear.

Forgive me...  I'm having Siemens issues myself right now.

old field guy

RE: Siemens Allis "Voltage Isolator"

Sorry never seen one Jeff.

Kinda dumb to call it an "Isolator" when it takes in one supply and makes two!  More like a "power supply".

Fire it up! See what happens.  I bet it works.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Siemens Allis "Voltage Isolator"

It looks like it is part of a power supply circuit.  The "Super-ISO-Pak" is a DC-to-DC Converter that, from the model number, takes an input of 24VDC and converts it to 12VDC.  The other components are associated with that Potter & Brumfield 24VDC relay.

RE: Siemens Allis "Voltage Isolator"

Isolator is in galvanic isolation, or no metallic path from one side to the other. Possibly an inverter style, so that isolation takes place in a transformer. Sometimes used to convert a grounded system to ungrounded, or positive ground to negative ground, or vice versa. This one could be center grounded on the output side.  

RE: Siemens Allis "Voltage Isolator"

Concur with the others, that's a DC-DC converter producing a bipolar output from a single-ended input. I'm going to take a guess that it is rated for 24V DC input, and produces +/-12V DC output. If it is dead Vicor have a pretty big range of functionally similar modules.
  

----------------------------------
  
If we learn from our mistakes I'm getting a great education!
 

RE: Siemens Allis "Voltage Isolator"

Good suggestion ScottyUk (star). I agree, instead of trying to 'rebuild' the old units, why not replace them with functionally equivalent units of modern construction. This would definitely be more reliable than rebuilding (repairing) the old units and may actually be cheaper.    

RE: Siemens Allis "Voltage Isolator"

(OP)
Thanks guys (assuming genders). I think that's the tack I'm going to take. I too interpreted it as a transducer, or part of a transducer, from a bygone era. I've requested a meeting with the technician who removed it so he can hopefully show me where it came from and what it was connected to.

Reverse engineering... one of my favorite challenges.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln  
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies  

RE: Siemens Allis "Voltage Isolator"

It might just be an isolation board for kyz pulse generation given the relay with 2 form c outputs.  If you can see the board traces, you could also draw the circuit diagram of the i/o.  Looks pretty simple.

Alan

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!


Resources