turning my scope on and off using a reed switch - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: December 09, 2021, 06:59:07 pm
content: Hi all,i have a mint hp 54503A scope,the issue is the on off switch is at the rear of the unit and awkward to get at with the scope on my bench,i want to find a way to turn it on and off without drilling holes for a front mounted switch,i thought of a reed switch and magnet,trouble is tho it needs to switch 3a at 240vac,i cant think of a way of doing it,can anyone come up with a solution?

author: engineer_in_shorts
author_rank: Regular Contributor
timestamp: December 09, 2021, 07:58:08 pm
content: Use a wifi enabled smart plug and command Alexa to switch on that scope'

author: engineer_in_shorts
author_rank: Regular Contributor
timestamp: December 09, 2021, 08:00:23 pm
content: In all seriousness I do like to put electronic soldering and diagnostic tools (scope) onto a dedicated switched mains outlet. So when I leave the bench I just have to hit one switch and know I haven't left soldering stuff on.

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 09, 2021, 08:03:17 pm
content: Quote from: engineer_in_shorts on December 09, 2021, 07:58:08 pm

author: m3vuv
author_rank: Super Contributor
timestamp: December 09, 2021, 08:21:42 pm
content: thats how it is running now,i guess im just lazy!,trouble is i have a 6 way outlet under my bench so if i turn it on it turns everything on!,i just want to be able too leave the scope plugged in and not have to grovel around the rear of it to turn it on,thought a magnet and reed switch was a way to do it as there is bags of room inside the scope,thing is the scope cosmeticaly is like new so dont want to butcher it by drilling holes etc,no issues mounting a pcb inside it tho,it may get drilled yet but dont want to,its driving me nuts fumbling around the rear of it to turn it on and off tho,what a total shit design,bit like having the steering wheel on the outside of a car!!!!WTF.

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 09, 2021, 08:28:52 pm
content: You could do this using a relay. Either a classic relay or a solid state one, driven by a circuit that would use the sensor of your choosing. There is some design here to be done, and safety will be a concern.

author: mag_therm
author_rank: Frequent Contributor
timestamp: December 09, 2021, 08:34:59 pm
content: How about a short extension cable with 3 pin and with in-line switch?They are available here in USA. $18 or soThere is also one with a remote fob.

author: x86guru
author_rank: Regular Contributor
timestamp: December 09, 2021, 09:23:10 pm
content: Please post a video showing us how well it works..

author: edpalmer42
author_rank: Super Contributor
timestamp: December 09, 2021, 10:44:51 pm
content: I had a similar problem with multiple devices. Either the switch was on the back or there was no switch at all.Eventually, I remembered that back in the day, almost every computer setup had a 'power center' which is nothing but a box with 4 - 6 switched outlets with a single cord and some kind of light to show which outlets are on. I picked up a couple of NOS units. One is used on my UPS plugs and the other is non-UPS.Ed

author: james_s
author_rank: Super Contributor
timestamp: December 09, 2021, 11:20:36 pm
content: Just mount a switch in a box at a convenient location and wire it to a power strip or even just an outlet in a box behind the bench. Plug the scope into it and mount the external switch wherever you want. Assuming it's a conventional hard power switch and not a soft button on the back, I see no reason to modify the scope at all.

author: james_s
author_rank: Super Contributor
timestamp: December 09, 2021, 11:22:24 pm
content: Quote from: edpalmer42 on December 09, 2021, 10:44:51 pmThose things are great, I have one with some arcade cabinets plugged into it, arcade games almost always have the switch on the back and mine are lined up against a wall. I just have the power center tucked in between two of them and I can individually switch them all right from that. My test equipment all has switches on the front where any sane person would put it so I haven't needed one for that.

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2021, 03:10:33 pm
content: ive decided to fit this when it arrives:https://www.ebay.co.uk/itm/402780472973?var=673023882771seems there is room to fit it above the row of buttons to the right of the crt,shouldnt look too bad and i concider this mod is gonna make the scope better to use so im gonna go for it,what do folks think?

author: langwadt
author_rank: Super Contributor
timestamp: December 15, 2021, 03:30:54 pm
content: https://m.media-amazon.com/images/I/61Di14T14ZL._AC_SY355_.jpg

author: james_s
author_rank: Super Contributor
timestamp: December 15, 2021, 04:17:53 pm
content: I hate mods that involve drilling holes, especially in the front panel. Why would you modify the scope when you can so easily use a remote switch and mount it anywhere you want?

author: mag_therm
author_rank: Frequent Contributor
timestamp: December 15, 2021, 04:44:23 pm
content: A step drill for sheetmetal reduces cuttings dropping inward.However I still got a cutting across tracks from drilling a panel hole on my project last week

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2021, 05:18:26 pm
content: i may look at it again when the switch gets here,i may fabricate a mount that uses the existing screws for the handle and top covers and fit the switch into that,i hate changing the looks of test gear unless it can be put back to stock,the power switch of design of this thing is a total ergonomic fuck up tho for me!,that way its reversable and doesent involve doing permenent alterations to the scope.

author: james_s
author_rank: Super Contributor
timestamp: December 15, 2021, 05:21:56 pm
content: It's just so easy to plug it into a switched socket though, that solves the switch problem and gives you an easy opportunity for also controlling the bench light and any other gear that has awkward switches. Solves the problem and keeps the equipment stock.

author: edpalmer42
author_rank: Super Contributor
timestamp: December 15, 2021, 06:15:31 pm
content: Quote from: m3vuv on December 15, 2021, 03:10:33 pmHow are you going to wire this in? You can't connect it in series with the power. The switch has no listed voltage or current ratings.Something like this:https://www.ebay.co.uk/itm/123788742763would be more appropriate. It's only 14mm wide so it should be possible to find a spot to squeeze it into.Nope. That won't work. Since you're in the land of 220V, you need a 2-pole switch. Maybe something like this:https://www.ebay.co.uk/itm/224195236303which is 15mm wide. This switch is rated for 250V@6A. Check the power drain of your scope. Remember that there will be a startup surge so you don't want to run the switch too close to its' rating. Note that it doesn't light up.Pushbutton-style switches typically have low power ratings which aren't appropriate for this type of use.Are you starting to lean in the direction of an external switch?Ed