Preferred order of binding posts? - Page 1
Forum section: electronics / projects

author: rmkilc
author_rank: Newbie
timestamp: February 23, 2017, 05:23:02 pm
content: I am building a lab power supply and trying to decide what order I should put the binding posts. If ground is in the middle, this allows the use of ashorting linkto short ground to positive or to negative. But this does not allow the use of dual banana plug adapters. If positive and negative are together, dual banana plug adapters can be used. Of all the lab power supplies I have seen, there doesn't seem to be an industry standard order. What do you prefer and why?

author: Kleinstein
author_rank: Super Contributor
timestamp: February 23, 2017, 05:48:12 pm
content: I would prefer PE - neg - pos. So you can use a standard link from PE to the negative side (which is the more common case) and can use the banana to BNC adapter.Another option would be a symmetric triangle with the ground above or below.

author: rmkilc
author_rank: Newbie
timestamp: February 23, 2017, 05:49:57 pm
content: Quote from: Kleinstein on February 23, 2017, 05:48:12 pmHaha I did think of the triangle idea but have never seen it done before.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: February 23, 2017, 06:14:55 pm
content: I've seen the triangle done, and like that best. Otherwise, positive on the right.

author: bitseeker
author_rank: Super Contributor
timestamp: February 23, 2017, 07:18:00 pm
content: The triangular layout isn't prevalent, but it does show up on occasion. Here are some examples.

author: Paul Rose
author_rank: Regular Contributor
timestamp: February 23, 2017, 08:32:33 pm
content: If you don't have vertical room for the triangle, but have enough horizontal room, then what about a (redundant) ground on both sidesground negative positive groundThen you can use a shorting bar on either side, but still use a dual banana plug

author: David Hess
author_rank: Super Contributor
timestamp: February 24, 2017, 05:52:01 am
content: Using a triangle neatly solves the problem and I have seen power supplies designed this way however ...Floating dual tracking power supplies actually have 4 connections: positive, negative, common, and ground. My Tektronix PS503s have the floating outputs in line with common in the center so with a fixed width banana plug, I am limited to 20 volts. Maybe next time I rebuild them, I will swap the binding posts around so I have 20 or 40 volts available.

author: bitseeker
author_rank: Super Contributor
timestamp: February 24, 2017, 03:58:46 pm
content: Diamond layout?Go+ o o -oC

author: prasimix
author_rank: Unknown
timestamp: February 24, 2017, 05:50:31 pm
content: Or maybe relay to make connection internally that could be also MCU controlled?

author: rmkilc
author_rank: Newbie
timestamp: February 24, 2017, 05:56:39 pm
content: Quote from: David Hess on February 24, 2017, 05:52:01 amIn your example, aren't negative and common the same thing? I assume you are talking about dual floating outputs that share a common negative.

author: David Hess
author_rank: Super Contributor
timestamp: February 25, 2017, 06:28:05 pm
content: Quote from: rmkilc on February 24, 2017, 05:56:39 pmWhy would negative and common be the same thing? I am talking about dual floating outputs which share a common; one output is negative and one output is positive with respect to common. And since the outputs are floating, any (or none) of the three terminals may be connected to ground as the user requires to produce a 0 to -20/-40 volt, a 0 to +20/+40 volt, or 0 to +/-20 volt supply. Usually ground is left disconnected preventing another ground loop but it is there if necessary.The last configuration is especially useful for powering analog circuits which require +/- supplies but can be referenced to anything so general purpose operational amplifiers can be used in low or high side circuits without limitations. The output voltages can be independent or track with any ratio.

author: rmkilc
author_rank: Newbie
timestamp: April 27, 2017, 09:53:17 pm
content: So after all that, this is what I ended up going with.

author: bitseeker
author_rank: Super Contributor
timestamp: April 27, 2017, 09:58:13 pm
content: Hehe. Thanks for the update!