Manual for Valhalla 2500E AC-DC Current Calibrator - Page 1
Forum section: electronics / general

author: vsmith
author_rank: Regular Contributor
timestamp: March 18, 2019, 11:34:53 am
content: Hi all,Since my post requesting manual info on my ESI Volt Box was so successful, I thought I would ask the group for help with getting a manual for my Valhalla 2500E Current Calibrator.There were a number of similar models made by the company (for example the 2500EP, which is quite different) and there are a couple of manuals posted online in various places, but I have found none that apply to the 2500E.My unit is working, and based on similarities with other 2500 models, I have been able to calibrate it, but definitely have questions about the proper way to test/set compliance voltage. The nomenclature for the various cal adjustments does not match that of the models for which documentation is available. (There are trimpots that are not referenced in the other manuals at all)I also have some basic questions about the unit, and others in the 2500 family. For example, I do notice that readings of output current (measured as voltage dropped across a precision load) drift or are "jumpy" on certain settings. I have had some success by lubricating the pushbutton switches (precision shunt current flows across the switch contacts). How do group members feel about the Valhalla current calibrators you own? What sort of difficulties or tips can you relate with regard to calibration and use?If anyone has a manual, I would love to get my hands on a copy!Best regardsVic

author: e61_phil
author_rank: Frequent Contributor
timestamp: March 18, 2019, 01:33:43 pm
content: I use my Valhalla 2500 as a source only. The DUT is compared against a precision shunt not directly against the 2500.

author: vsmith
author_rank: Regular Contributor
timestamp: March 18, 2019, 03:01:51 pm
content: Thanks. How stable is the output oif yours? Both in terms of drift and "jitter"?

author: e61_phil
author_rank: Frequent Contributor
timestamp: March 18, 2019, 03:33:13 pm
content: Hard to say. If you are interested in a special range I can do some measurements.

author: vsmith
author_rank: Regular Contributor
timestamp: March 18, 2019, 07:46:38 pm
content: Thanks!I would be interested to know how much drift you see in a 10 minute period with an output current of 1 amp. And whether the readings in any 10 second period are stable or change plus or minus some amount around a mean reading.(obviously the output reflects the stability of the input as well as tghe resistance of the load, so some description of the test set up and source as well as the load would be helpful)Vic

author: e61_phil
author_rank: Frequent Contributor
timestamp: March 18, 2019, 10:50:27 pm
content: After ca. 1.5h warmup it is still drifting. However, one can see it will not be more stable than ~5ppm.I used a Fluke 5440B as 1V source, a Burster 1R shunt and I monitored the shunt voltage with my 3458A.Last year I build a simple 1A current sink (1A_current_sink.png). That is much more stable than the Valhalla, but the Valhalla can reverse polarity very easy

author: vsmith
author_rank: Regular Contributor
timestamp: March 20, 2019, 08:34:47 pm
content: E61_PhilThanks for going to the trouble and taking those measurements for me.That is quite similar to what I am experiencing here.Your current sink project is really interesting, thanks for that as well!BestVic

author: seebeck
author_rank: Contributor
timestamp: May 04, 2019, 01:50:21 pm
content: I shared the manual as attached.Other one called “VALHALLA 2500EP Operating & Maintenance” is too big, could you please told me your E-mail via message I will share it with you.

author: Magnificent Bastard
author_rank: Regular Contributor
timestamp: May 04, 2019, 02:06:39 pm
content: Quote from: seebeck on May 04, 2019, 01:50:21 pmTry compressing the manual with this link:https://smallpdf.com/compress-pdfIf you can get it down to <= 1MB, you can post it in another message.

author: seebeck
author_rank: Contributor
timestamp: May 04, 2019, 02:40:01 pm
content: It is very useful.

author: seebeck
author_rank: Contributor
timestamp: May 04, 2019, 02:42:25 pm
content: another one

author: beanflying
author_rank: Super Contributor
timestamp: May 05, 2019, 12:10:36 pm
content: Not sure if there is a reason for files over links but both manuals are still on the Valhalla site. The google search links are busted so I gather there has been a recent site upgrade. Manuals Download pagehttps://valhallascientific.com/resources/manuals/2500https://valhallascientific.com/wp-content/uploads/2018/09/2500_Manual.pdf2500 EP/ENhttps://valhallascientific.com/wp-content/uploads/2018/09/2500EP_Manual.pdfand the big boy 2555Ahttps://valhallascientific.com/wp-content/uploads/2018/09/2555A_Manual.pdf

author: vsmith
author_rank: Regular Contributor
timestamp: May 23, 2019, 06:43:59 pm
content: I wish one of those was for my 2500 E.It's frustrating, because I see them for sale every so often, yet I can never find the manual.Here's a picture of a 2500E. It looks to me as though the major differences from the straight 2500 is that there is a 10Amp range and a series of LEDS which show output voltage compliance status. Unfortunately that means that there are several additional calibration adjustments, and I have so far been unsuccessful at determining how to set them.I wrote to Valhalla, and got an answer, too, saying that they needed to look in the archives. That was the last I heard from them, even though I did send a follow up email.I am hoping someone will eventually see this and post the 2500E manual!Thanks everyone who posted manuals for the other versions of the Valhalla 2500 series.

author: GEOelectronics
author_rank: Regular Contributor
timestamp: July 17, 2019, 09:40:43 pm
content: Hello, could you please email a copy of the ESI Voltbox manual?ThanksIs there a [lace where we can swap ESI manuls? I do have a few.George DowellK0FFmy email is GEOelectronics@rallstech.net

author: vsmith
author_rank: Regular Contributor
timestamp: July 26, 2019, 05:02:53 pm
content: Hi Georgethat manual has been emailed to youcheersVic

author: alm
author_rank: Super Contributor
timestamp: July 16, 2021, 12:24:28 pm
content: I realize vsmith and the others in this thread may no longer even own this instrument, but this thread is ranked high on Google when searching for this manual, so I figured I'd upload it for future reference.I own a paper copy of an early Valhalla 2500E/2500EP manual. The two instruments share a manual, with the only apparent differences the remote control and the fact that the 2500EP range switches are relays instead of buttons. Compared to the more recent 2500EP/2500EN manual on the Valhalla website, the schematic was clearly redrawn and the component designators changed. I haven't looked closely for other differences. This was a scan with the CamScanner app on my phone, which I think produces decent results, except for not keeping the folded pages 100% flat. This is the best I can do right now, though. The schematics aren't great quality even in the original. I'm guessing this was a photocopy made by Valhalla, since it's in a Valhalla binder. The 2500EP schematic is better quality than the 2500E schematic, so that might be of help.Since the manual is too big for the forum, and I don't want to reduce the quality by compressing it, I'll upload it as a multi-part RAR in four parts, with each file zipped individually to work around forum file type limitations, across two posts. I also uploaded it to KO4BB, BAMA and Xdevs, but it may take a while until it's available for download from there.

author: alm
author_rank: Super Contributor
timestamp: July 16, 2021, 12:44:16 pm
content: Part 2

author: vsmith
author_rank: Regular Contributor
timestamp: August 10, 2021, 12:32:47 pm
content: Hi AlmThis is excellent! Forgive me for being later to realize that you had uploaded these manuals, it has been a chaotic summer around here. Thank you so much for scanning and uploading these. I will take a look as soon as I have time and see if they are a match for the unit I have (Yes, I do still own it....can't seem to get rid of much around here....)Vic

author: kbrill
author_rank: Contributor
timestamp: August 12, 2021, 02:08:41 pm
content: Thanks

author: kbrill
author_rank: Contributor
timestamp: August 13, 2021, 02:01:52 am
content: The front panel of my 2500ep is considerably different from others I have seen in Valhalla manuals and literature

author: beanflying
author_rank: Super Contributor
timestamp: August 13, 2021, 02:36:53 am
content: Same front panel as my 2500EP but there is some variants.