Mains connection parts?

[mirage_indigo]

What part are folks using for their mains connection? I've used a straight up 3 wire power cord with strain relief and chassis grommet on the last project, but wondered is there was something more standard or aspirational. Is there a favorite IEC module with fusing?

[Phil_S]

I like the IEC. The cord generally free. Go the the IT shop at your place of work or a computer repair shop. They will have more spares than you can count. They will give you a few if you ask (nicely.) While you are there, ask for the dead power supply modules. From these, you can harvest the IEC socket, complete with ground wire and lug.

The IEC cutout is a PITA to make without the correct punch. The punch is very, very expensive. If you have a CNC, you could program the correct cut out. Having said that, I have done them by hand, drill and file method. It takes 20-30 minutes. The IEC socket will cover the imperfections. I've heard of people doing them on aluminum with a router and homemade template.

The IEC is nice if it has an internal fuse, but that's not needed. Often they come with a fuse value you can't use, so you'll pay extra for the fuses.

There is nothing wrong with a regular cord with strain relief. The strain relief really should be seated in a hole that has a straight side to mate with the flat side of the strain relief grommet. I suppose you can cheat and use a round hole. I don't know if that affects it. Cord and strain relief is certainly as "standard" as IEC.

[xtian]

In new builds, I use IEC inlet as long as cord is inserted horizontally into the chassis, not vertically under the chassis (because it will possibly fall out). The best IEC connectors are metal, and mounted from outside of the chassis. This hides my rectangular hole, which I make by drilling four 3/8" holes in the corners, then cutting the hole with a jigsaw.

Most recently, I used this one, with integral fuse holder. I liked it.

https://www.tubesandmore.com/products/r ... use-holder

[SoulFetish]

I'm loving IECs because of the convenience of a detachable/replaceable cord is the way to go in a lot of ways. But for me, the convenience ONLY starts once the IEC jack is installed . Did not have access to a laser cutter/milling machine, or a punch, so I dreaded having to "drill" a square hole and file it out. It was a pain in the ass on my first build. So, I wanted to try and somehow do a little thinking before hand and see if I could make the job a little easier, and a lot cleaner. With the tools I had access to at the time, the only way of doing this was to try and remove as much of the metal as I could with my drill press and minimize the filing. But I was not going to drill a small dotted line around the perimeter of the hole, leaves to much room for mistakes and would take forever. So here is what I did: I made a template for the specific part I spec'd - Schurter 6200.2100 (which is a very high quality, German made part). It screw mounted, with solder tabs.
Then I essentially drilled out the four corners, and removed the bulk of the rest of the material in the center using my step drill. The filing took less than 5 minutes, and was easy peasy.
right now, it looks like mouser has the best price on the part:
https://www.mouser.com/ProductDetail/Sc ... Yb7fUmQ%3D
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IEC jack corrected.jpg

IEC technique step2.jpg

IEC hole.jpg

IEC jack Mounting holes.jpg

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Oh, taking the time to center punch all the drill holes is totally the way to go. The whole process ended up working out nicely, and I was really happy with the quality of the results.

[SoulFetish]

One other suggestion to make your life and work easier and the results better...
If you want to properly install a industry approved and secure strain relief on a power cord, I would highly recommend getting a tool designed to do it. Using needle nose pliers or slip joints sucks.
I use a Heyco No. 29 tool, and I'm never going back. But I use it really almost daily in the shop, and my boss has had his for over 30 years.
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IMG_4238.jpg

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They are absolutely worth the money.
But if you are not going to be building more amps or doing repairs, then you can probably get away with one of the cheap stamped metal ones.

[xtian]

you can probably get away with one of the cheap stamped metal ones.

That's what I use, the cheap one. It's great!

[Phil_S]

I hadn't realized the IEC with fuse is a rectangle. That's really not too much of a challenge with drill and file. I was talking about the ones without the fuse. On the top it is half a hexagon and the bottom is a box without the lid. It takes some patience with both drilling and filing so that you don't color outside the lines. Anyone know the correct radius or drill bit for the (bottom) corners? BTW, I use a round chainsaw file to perfect the corners, but I think the radius is wrong.

[xtian]

Phil, just get the kind that insert from the outside of the chassis--these hide your dirty work.

[Phil_S]

Aaron: Yes. But I know it's there. Can't help myself. I'm the kind of person who will fix it until it's broken. The only thing between that and not doing it is that I'm older now and experience is a source of restraint. I've even had some success at plumbing, where it is critically important to screw things together just enough, but not too tight.

[SoulFetish]

your not going to be able to drill the "perfect" radius because it's a max R3, you'd end up drilling past the ideal outside mounting dimensions.
But a #2 drill will get you as close as you'll ever notice. just watch for runout.

[SoulFetish]

on second thought, a 7/32" or 5.5mm drill diameter might allow for a little more "wiggle room" here and still work fine

[Phil_S]

The problem is using a punch to insure the edge of the hole is properly tangent to the outline. I am not good at this. As a result, I generally drill away from the line and sneak up on it with a round file. I've been using a 7/32" chain saw file. So, it turns out I'm doing OK! The rest is done with a variety of flat files.

[boots]

Someone recently turned me on to using a sheet metal nibbler for IEC and transformer cutouts. Works very well, although it does still take some practice and patience.

[Colossal]

As an alternative, a router with a 1/4" flush cutting bit gets it done very quickly and cleanly. You can make your template out of masonite or MDF, or a 3D printer if you have one or access to one.

[M Fowler]

Someone gave me crap for spending my money on an rectangle panel punch; however, I don't think they understand how many amps I've built before I purchased that IEC punch.

I don't regret the purchase at all but very expensive.

Before that I used dremel with small disk cutter; or drilled large holes with a nibbler to enlarge then file to smooth; or multiple small holes, use pliers to pull parts off, then file; or drilled several holes to cut out with sabre saw. All of those methods suck.

I also get lazy or for a reason or two have to use a round hole with screw together power cord restraint.

For Fender amps I have a $7.95/free shipping from China restraint pliers that works great.

If you only build one amp or several just use whatever method you can, I understand you don't want to invest in so many tools but I use them in snowmobile repairs, mini bikes, motorcycles, truck, car and my 32 Ford Roadster. Forgot the skid-steer.

Mark