Soldering station thoughts and guidelines

[Dannyx]

Re: Soldering station thoughts and guidelines

The stray voltage will be enough to damage semiconductors!

Yeah, I may have killed some stuff too because of this without even realizing it So it's ground or bust from now on. Sadly there isn't anything metal around which I can use for grounding, so the long wire idea is probably the way to go.....unless it turns out the wire itself acts as an antenna and ends up picking up stray voltages

[Agent24]

Re: Soldering station thoughts and guidelines

Make sure there is a 1Megohm resistor between the iron tip and earth, so you don't short anything to ground if you accidentally solder something live. Also this limits current of ESD events.

It could also be a fault in the tip/handle or bad design of the power supply making the tip live.

[Dannyx]

Re: Soldering station thoughts and guidelines

I'll actually open the thing up to have a look see. It's SMPS-based, so it doesn't quite make sense for the tip to go live, since the outer housing should be like chassis GND...you never know with chinese products. They sometimes skimp on safety features or just implement them wrong

[stj]

Re: Soldering station thoughts and guidelines

it makes perfect sense,

the outer tube of the tip is earthed to ground/0v

and switching psu's have a ceramic cap between the primary side and 0v on the secondary side.

[sam_sam_sam]

Re: Soldering station thoughts and guidelines

So what is the solution to this problem that is realistic that will not require a complete makeover

Is this the switching power supply that comes with the unit or is this some other brand power supply

Does happen when you using on house current or is this on battery power unit
Please answer this question because this is very important

[stj]

Re: Soldering station thoughts and guidelines

it's capacitivly coupled mains from the psu - *all* switching psu's do it - all switching psu's should have an earth - including phone chargers.

infact especially including phone chargers with the growing number of idiots using earbuds at the same time as the charger!!

[Dannyx]

Re: Soldering station thoughts and guidelines

Ok guys, here's the insides of this soldering station: just a SMPS which accounts for 90% of the space inside and the business end at the front. I added my binding post on the back next to the IEC plug and soldered it to the earth prong. I haven't tested it out yet You can also clearly see the cap between HOT and COLD GND there.

[momaka]

Re: Soldering station thoughts and guidelines

it makes perfect sense,

the outer tube of the tip is earthed to ground/0v

and switching psu's have a ceramic cap between the primary side and 0v on the secondary side.

Exactly.

Though that cap between secondary ground and primary negative (-) bus should NOT be a REGULAR ceramic cap (I'm sure you know that already, but just stating it for anyone else in the thread who may not be aware.) It needs to be safety-approved Y2-class rated. The difference is that Y2 caps will not fail short-circuited in the event of over-voltage or breakdown, whereas regular ceramic caps can. This leaves the potential (pun intended) for regular safety caps to fully energize the chassis of the device if it is ungrounded ("double-insulated" as some devices claim... though I only think that applies with devices that use a regular line-connected transformer - now these are truly double-insulated.)

That said, even with a Y2-class cap between ground and primary negative (-) bus, there will still be a small leakage current, hence why you get the slight shocks. The unloaded voltage could actually be pretty high - as high as 160V AC. But due to the low capacitance of the Y2 cap, the current is limited and very tiny.

Unfortunately, that cap needs to be there for the PSU manufacturer to comply with EMI/RFI standards. But it does create problems for ungrounded devices - particularly soldering irons, as you can easily destroy ESD-sensitive components.

So on that matter, I agree with STJ: the PSU needs to be grounded.

Make sure there is a 1Megohm resistor between the iron tip and earth, so you don't short anything to ground if you accidentally solder something live. Also this limits current of ESD events.

+1

This is certainly the recommended way to do it.

[Dannyx]

Re: Soldering station thoughts and guidelines

So I should add a 1 Meg-ohm resistor between the COLD GND (chassis GND )and that ground binding post I added which goes to earth ?

[stj]

Re: Soldering station thoughts and guidelines

no, add the resistor inline with the iron connector.

IMO you want to limit the ground current to the tip, but not the case or a case short wont blow the fuse!

[Dannyx]

Re: Soldering station thoughts and guidelines

When you say "iron connector" you mean the shell of the connector ? I think the metal part of the iron is connected to the chassis of the station anyway....must admit I haven't tried measured.

[stj]

Re: Soldering station thoughts and guidelines

well you need to find out how the iron is wired,
i wouldnt be surprised if they dont actually use the shell, because screened cable would cost more.

[Dannyx]

Re: Soldering station thoughts and guidelines

Does anyone on this board happen to have a Weller ET series soldering station ? I cannot find anything about the inner diameter of the tips. They SEEM to match my cheapy Gordak 900m knockoff. The tips for the Weller look like this.

[stj]

Re: Soldering station thoughts and guidelines

those may be solid and not hollow.

[Dannyx]

Re: Soldering station thoughts and guidelines

those may be solid and not hollow.

I feared too myself, but THIS article makes me think they're hollow (notice how the element goes inside the tip piece - at least that's how I see it.....). This would open up the possibility of using decent quality tips on my low end iron....which may not necessarily yield the best results in the end, but better than nothing.......

[stj]

Re: Soldering station thoughts and guidelines

that's interesting, the element is on the outside and the thermocouple is in the center!

gotta say though, if you need a webpage full of pictures to change a tip, you probably shouldnt be using the iron!

[Dannyx]

Re: Soldering station thoughts and guidelines

If it turns out the ET series iron is similar to my cheapy Gordak, it opens up the possibility of using an ET to LT adapter, which are these stubby tips for the LT series....apparently Weller thought of this and made an adapter....that's right: a soldering tip ADAPTER !

Sadly, it looks to me the retaining sleeve is shorter on my Gordak and the nut may not match either, at least without any official dimensions and no other points of reference in any of the pics I found so far....I can't believe they do not provide this sort of info. I guess to prevent this sort of attempted "cross-compatibility"

[stj]

Re: Soldering station thoughts and guidelines

try ali-express for a clone weller handle

[Dannyx]

Re: Soldering station thoughts and guidelines

try ali-express for a clone weller handle

Yeah but it'd have to match my Gordak which involves a bit too much work figuring out the pins and voltage and that....

[stj]

Re: Soldering station thoughts and guidelines

if they both use K type sensors then it's easy, i know a guy who put a xytronics handle on a gordak by just re-wiring the plug - the xytronics iron actually had the right one - just wired different.