Is anyone able to read ~30 year old PADS schematics? - Page 1
Forum section: electronics / projects

author: Konkedout
author_rank: Frequent Contributor
timestamp: February 23, 2025, 05:38:09 am
content: I have my own electronic load on my lab bench. Right now I only have a hard copy of the schematic, and a scanned image of it.Is anyone able to open my old PADS schematic files and provide clean high resolution .pdfs?My load has worked well for all these years and everyone is welcome to the schematic if you want it. It has 20A, 2A, and 200 mA ranges and works up to 55VThanks!

author: georges80
author_rank: Frequent Contributor
timestamp: February 23, 2025, 05:51:36 am
content: Something like the attached?cheers,george.

author: Konkedout
author_rank: Frequent Contributor
timestamp: February 23, 2025, 06:31:02 am
content: Thanks a lot but..My fault...I cannot see what I am ;posting. That one is the self powered version, powered by the unit under test. Later design than what I have on my bench.I have attached a scan of what I am looking for. It is very possible that I just do not have the original PADS version of that design. I know there was a Win and a DOS folder in the zip. Were those both the same design?And I had no idea that the schematic would be in color. If it is easy to plot in B&W that is better. Only if you can see the schematic which agrees with my posted scanned version.Thanks again.

author: georges80
author_rank: Frequent Contributor
timestamp: February 23, 2025, 04:51:22 pm
content: The dos folder has 2 files, the win has one file.I looked at all 3 files and none of them contain the transformer circuitry of your second page of the scanned PDF. The pads files have 3 schematic pages each... and appear to be the same/similar at a cursory glance.cheers,george.

author: Konkedout
author_rank: Frequent Contributor
timestamp: February 23, 2025, 06:44:09 pm
content: OK thanks a lot! I appreciate your help.

author: CaptDon
author_rank: Super Contributor
timestamp: February 23, 2025, 11:18:38 pm
content: What is PADS? We have done ORCAD and half a dozen others and I never hard of PADS. Are there converters like PADS to .ORC or .DWG and so forth?

author: Konkedout
author_rank: Frequent Contributor
timestamp: February 24, 2025, 06:07:29 pm
content: It looks like PADS now belongs to Siemens.https://eda.sw.siemens.com/en-US/pcb/pads/

author: Chris56000
author_rank: Frequent Contributor
timestamp: February 26, 2025, 02:08:40 am
content: . . .What specifications are the transformers T1 and T3? Are they commercially available or can be made?Chris Williams

author: Konkedout
author_rank: Frequent Contributor
timestamp: February 26, 2025, 06:35:48 am
content: Hi, ChrisRegarding the transformers, I have to be honest and say that I do not remember exactly what is there, but that I made them. The way they operate is not very critical compared to a transformer handling high power levels.I think they are probably ferrite toroids because that is what I had handy. Those particular transformers are used only for low power levels in which I pass the output through the rectifier to turn on a high voltage bipolar transistor. The power transistor + bridge rectifier acts like a triac to switch AC power to a fan and to the contactor relay. (Two similar circuits but both are not many watts.)Understand that when I have a stockpile of parts, much of my design is based on the parts that I have. It is not the way I would do it if I had to buy everything. If I were buying the fan and the relay, I would have bought 12 VDC operated fan and relay. That would have been MUCH SIMPLER. But I had the 120 VAC operated fan and relay and most of the other parts, and wanted to try what I did. I know that the relay driver has been working as intended for all of these years. But the fan has never come on I guess because the heatsinks have not gotten hot enough.Some users of this forum will want to know how I got my stockpile of parts. That happened two ways:1) For about 18 years I was a design engineer for a company which actually built power supplies. If they had parts in the stockroom which were no longer used on a design for > 1 year, they got rid of them to avoid paying tax on inventory. Sometimes they would take the parts to a surplus dealer but that place paid only pennies on the dollar and it may have been worth it to drive the parts over there. So sometimes I simply volunteered to take the parts and there were not many other employees similarly interested. I did not have a lot of competition.2) For about 12 years I was an FAE for two different semiconductor companies. I worked out of my house (many FAEs do this.) I actually designed and built Eval boards for customers. I could buy & expense the parts I needed to do this with, and I also got samples from vendors which wanted to have their parts on our Eval boards.So with all of that, I do have parts I can use, but when I want to build something for myself now (I am mostly retired) I still will need to buy SOME parts.Also I really just wanted to try doing it the way I did it