Finding a DPDT slide switch by pin layout dimensions - Page 1
Forum section: electronics / beginners

author: humgar
author_rank: Regular Contributor
timestamp: November 21, 2022, 12:44:14 am
content: I have an old DPDT slide switch (likely made in the last century) that I'd like to replace because the actuator shaft was broken. The pin pitch/spacing looked very familiar as it's identical to a typical voltage selector slide switch, but I can't find one on mouser/digikey with the same pad footprint.Can anybody help me to identify the actual or a compatible part number? It's used in high precision test fixture HP 16060A so preferably with minimal contact resistance. Many thanks in advanceHere are the hi-res pictures of the switch and the board it goes into:https://humgar.com/_misc/3101-2850/

author: EPAIII
author_rank: Super Contributor
timestamp: November 21, 2022, 11:49:33 am
content: Get an inch scale with 10 and 20 graduations per inch - at the very least. I have a small triangular one with 10, 20, 30, 40, 50, and 60 divisions per inch. I keep it handy on one of my electronic benches.Just a wild guess, but your switch seems to have the terminals on a 0.25" x 0.30" grid.Unfortunately the electronic supply houses do not allow slide switches to be selected by the pin spacing. Your best bet would be to follow the links on their sites to the manufacturer's sites and look there for a way to choose by the pin spacing. There are around one to two dozen OEMs to check so it may take some time. Here are two searches of the Mouser and Digi-Key sites narrowed down to DPDT and pin or solder terminal type terminals.https://www.mouser.com/c/electromechanical/switches/slide-switches/?contact%20form=DPDT&switch%20function=ON%20-%20ON&termination%20style=PC%20Pin%7C~PC%20Terminalhttps://www.digikey.com/en/products/filter/slide-switches/213?s=N4IgjCBcpgzADFUBjKAzAhgGwM4FMAaEAeygG0RYAWeKgNipAF0iAHAFyhAGV2AnAJYA7AOYgAvkQBMsAKxIQqSJlyES5SgA4p8OlOZtOkHv2FjJIKbM0KlK-EVKQKsTVTf6iNWfBkGQHFy8gqISFvrOIDhYAgAmeAAEOADuAuzIABbM4kA

author: humgar
author_rank: Regular Contributor
timestamp: November 21, 2022, 09:33:17 pm
content: I measured it with the caliper, the short side is 0.25 inch (center to center) and the long side's pitch is 0.275 inch (center to center). Before asking here, I already tried getting the datasheet for each brand in the search results from mouser and digikey (actually there are only a few distinct datasheets there), and I couldn't find anything that has this exact pin spacing. The closest ones I could find have 0.25 inch for both long and short side. If the long/short sides are slightly different, it's the short side that has the wider pitch, which is the opposite of this one. I also searched TE (Amp) and they do not have parametric search by pin pitches either. There are only 30 DPDT switches anyway but none of them have this pitch spacing pattern.Good idea about getting a ruler with finer graduations. Is there a name for it? It'd be useful for taking pictures as a reference. Caliper often gets in the way for photos.

author: EPAIII
author_rank: Super Contributor
timestamp: November 22, 2022, 02:41:19 am
content: If you have looked at the various datasheets, I am out of ideas for an exact match. Well, you could/should try HP if you haven't already.I can suggest two ways of using a switch with the incorrect spacing. First you can buy one that will physically fit and bend and/or extend the pins. You may need to find one that is shorter in height if it is a tight fit in the available space. The pins can be cut fairly close to the bottom of the switch, leaving only the diameter of some buss wire protruding. With the buss wire laying flat on the bottom of the switch, bend it around the terminal and solder it in place. Once the solder joint is good, clip the terminal flush with the buss wire. Finally bend the buss wire to create a new pin at the needed location. Then you will have added only the diameter of the buss wire to the height of the switch.A second way would be to drill new holes or file the existing ones into slots, but keeping as much of the foil pads as possible. The pins of the new switch can be bent over after inserting it in the new hole pattern to give them good contact area with the remaining foil. Not the best way if you like your vintage electronics as pristine as possible, but it will work.As for that ruler, other then the scales themselves, the only markings on it are:ENGINEERAlumicolorCode 3211and Made in El SalvadorI do not remember where I purchased it, but when I searched for an Engineer rule Code 3211 I was surprised to come up with this:https://www.amazon.com/Alumicolor-3211-1-Aluminum-Engineer-Pocket/dp/B004BNHA5AThat seems to be the exact one and I often buy from Amazon. They have different colors now and I may buy another one or two. I also had other hits. Here's one:https://www.engineersupply.com/Alumicolor-3211-1-6-Engineer-Pocket-Scale-with-Clip.aspx?VariantId=87fcc7b3-5fba-474f-a6cf-299e234a44e4&gclid=Cj0KCQiA4OybBhCzARIsAIcfn9kymEsqi3JT_N2sXGr4K-4trfBSEVkN00hvtk4--tFx4EmvSBiHMNsaAgK2EALw_wcBAnd a bunch more. My search was:https://www.google.com/search?client=firefox-b-1-d&q=Engineer+ruler+Code+3211Quote from: humgar on November 21, 2022, 09:33:17 pm

author: andy3055
author_rank: Super Contributor
timestamp: November 22, 2022, 04:02:05 am
content: If you are sure it is DPDT, try this:https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=dpdt+slide+switch&_sacat=0There are many other configurations on Mouser. Check the coloumn "Contact From."https://www.mouser.com/c/electromechanical/switches/slide-switches/?q=sliding%20switch

author: humgar
author_rank: Regular Contributor
timestamp: November 30, 2022, 06:51:09 am
content: Thanks. That's the first thing I tried, but they don't provide the datasheet or footprint nor the part numbers on eBay so it's impossible to research it.

author: humgar
author_rank: Regular Contributor
timestamp: November 30, 2022, 06:53:46 am
content: Thanks. I emailed keysight but they are slow at getting back to me (probably holiday season).I'll definitely look into the ruler. The pictures provided by the manufacturer is so blurry that I cannot make sense out of the graduations. How does the 3 sides work? It looks like all sides are either all Imperial or all Metric. What's the difference between the 3 faces of the ruler?

author: BILLPOD
author_rank: Frequent Contributor
timestamp: November 30, 2022, 06:53:14 pm
content: These rulers are very handy for an electronic's workbench:https://www.adafruit.com/product/1554.

author: humgar
author_rank: Regular Contributor
timestamp: December 07, 2022, 10:19:17 am
content: Cool. The graduations isn't fine enough though