Hi im thinking of picking up a soldering iron and im wondering what type of solder is the best in terms of health
11992
I'd like to do some hobbyist soldering at home, and would like to make sure I don't poison those living with me (especially small children).  Lead-free seems necessary - what other features should I look for in solder?  Are the different types of solder roughly the same in terms of safety (breathing the fumes, vapor fallout, etc.)?  Is there more I should do to keep the place clean besides having a filter fan and wiping down the work surface when finished?
99737
What is / how can I get a student-safe power supply for electronics projects?  I'm looking for a student-safe power supply for solder less breadboard.  I'm developing a course to teach electrical engineering to grade school students as an after-school program.  I'm wrapping up the first course and I've learned a lot, including that I need to find a safer power supply.  We're mostly using 9V batteries and connecting them to the breadboard via alligator clips.  After lots of searching, I'm realizing that I need to turn towards the expert community for guidance.  I hope that with the rise of the Makers  this question will become increasingingly relevant with time as more kids get into electronics.  Inextricably linked to this question is what is the minimum power source to use.  I've liked using 9V batteries since we can connect to them using alligator clips; but I worry that they are just a little too powerful.  I can imagine them somehow starting a fire with them.  My #1 priority is to keep the students safe.  Kids just have no concept that they can cause damage to themselves and property.  When I ask "where is that smoke coming from?" I'll get a gleeful response from the student that is seeing how many batteries he could hook together and short out.   I really need to limit the damage they can do.  I mainly don't want anyone electrocuted or anything to catch fire.  Kids will routinely attach LEDs backwards, leave them like that and then act surprised when they explode.   After safety, I want to protect the equipment.  Kids will hook up a LED backwards all the time.  After protection, I want to give the kids feedback as to what is going on.  A light that indicates power is on would be awesome.  A light or siren or circuit break that indicated a short would be awesome too.  Battery powered supplies are slightly preferred, just to keep upfront costs low and to avoid having to run outlets to each table.  Boundaries:   We are only using simple LEDs, BJT transistors, resistors and maybe a timer IC.    Similiar Questions:       References:  Course details are here:   We currently sometimes use  from the Squishy Circuits Store and/or a 9V battery with alligator clips.  Epilogue  I found it tougher than expected to find a suitable wall wart, so I'm listing what I finally found for future reference.  I'm about to test the following combination:         Epilogue 2  A year-plus in, I've decided to drop the in-line power switch since it wasn't obvious when it was 'on' vs. 'off'.  I'm instead relying upon the students to unplug the rat-tail from the supply, which is quick and easy.  Also, since I'm primarily using this for a squishy-dough project, I'm experimenting with with using two button batteries instead of a wall power.
33687
Is there a test to determine whether solder is leaded or lead-free? Perhaps conductivity/resistance?
116427
I am a beginner at electronics.  I don't have many tools and stuff, so I am forced to solder by hand.   I don't have a pcb to solder on, so I usually just solder the wires together, but it's really difficult without a holder.  Is there an easier way to do this? If not, is there a substitute for a wire holder?  Any help would be appreciated.
6509
I just purchased a new cast iron skillet. What's the best way to season it?   And if I need to re-season an old pan, is the process any different?
120956
I was reading about tin alloys for electronics soldering and found it it has about 40% of lead in composition. Lead, everyone knows, it's very dangerous to breathe due to being a heavy metal. Also, I found some recommendations using the combination of an exhauster and a respirator when working with soldering. Is there any international regularization of which respirator type should I use? If not, which type do you recommend? Beyond this, is there any additional safety equipment recommended?  For economics reasons and for better soldering resistance, I've already discarded Pb free solder reflow.
17856
I need a wire nut large enough so that I can bundle seven 14 gauge neutral wires together. I am trying to splice it so I can connect it to my new smart wifi leviton light switch.  I don't know which wire nut size to buy.  The boxes say for example: minimum 2#14 gauge - maximum 2#10 gauge.   My question is, can you tell me which wing nut or brand or size to buy so I can group 7 neutral wires together? None of the sizing chart on the box says the exact words of "ok to bundle seven #14 gauge wires together.  Which one should I use?
111027
I am thinking about ordering up some parts for every day use. I am thinking about making one big purchase so as to minimize on shipping and other charges.   What are some of the components that any electronics hobbyist should have around ALL the time?  To put a little more scope: typically working with Arduino's, PICs and sensors. 5V - low current projects.   Looking for: component, value or range (if any), manufacturer (optional)   For example -  Resistors, 1K through 100K 5W
76702
I have a number of  I would like to use in a project. The problem is that they're not quite powerful enough so I've been trying to come up with ways to increase the their pulling force without increasing the voltage.  The solenoids use a core that is tapered on the end. I would think that would lower the pulling power when the solenoid first engages. If I replace the core with a one that has the same thickness would I be right in thinking that the initial pull when the solenoid engages would be stronger?  If this would work what type of core should I use? If I just google "steel rod" there is a lot of types available. Is there some in particular material I should be looking for?
115551
I'm trying to free my aluminum seatpost corroded to a CrMo frame. One of the methods is to heat the aluminum seatpost and then to let it cool. In theory, the aluminum will expand twice as fast as steel and hence the expansion/contraction should crack the bond. Some recommend using a blow torch or even boiling water. I don't have access to a blow torch, but was wondering if there was something better than boiling water.
123770
I'm looking for a list of nearly all elements and the temperatures they can reach when in a state of plasma. It is for a project I am working on. However, there isn't a list on google.  Preferably one that is hot enough to survive a drop from orbit.
118023
I thought that choosing the right MOSFET for my LED strip would be easy until I discovered how many different models there are.  Basically I want a MOSFET that allows me to control with PWM a 12V 6A (MAX) led strip, but every time I see the Vgs I get confused because of numbers like +-20V.. (I'm controlling it with an ATtiny13A or ATtiny85 - 5V pin output)  I done a lot of searching a came across a lot of different models: IRFZ44N, TIP120, STB36NF06L and a bunch more.. but I not sure if they will do the job  What MOSFET should I use and how do I read in the datasheet why this is a good choice?  I am new to hobby electronics.
81021
I have some experience with highfrequency circuit analysys. However I am a newbie in PCB design. I am analysing this circuit:  (starts on page 36) and regularly see things like "OMIT" for headerpins or components like resistors or so.  e.g.:   p41 (6/6): the boxheader(?) on the left. P40 (5/6): R48 on the dev board are two small surfaces with some soldering on it but no component apparently. I can hardly see myself (de)soldering resistors on my new dev board...   Why is this being mentionned? What do the people who made the PCB mean by this?  I mean if this part has to be omitted, why did they even place it on the PCB?  Thx
68324
If copper is more conductive than water (at any reasonable PH), submerging copper electronic circuits in should have no effect, as the electricity should continue to follow the path of least resistance (the highly conductive copper PCB paths, for example) rather than shorting into the mildly conductive water.  However, dumping water on electronics clearly shorts them out, even though copper is the superior conductor.    Why does this occur when the path of least resistance should be the copper rather than the water?
64907
I was looking at this  which has strange interface pins. I have never seen anything like it.  I wonder how am I supposed to connect to them. What connectors can I use and what's special about them? Is it good for RF stuff for example? What are they called? I could research more if I knew what these pins are called.  Edit: Answered in the comments: They are turret pins where you wrap a wire and solder to.
35311
I've been wondering about this for a while, since getting interested in knife sharpening.  When using a knife, it will get duller. One (the primary) reason being that you "bend" the edge. You fix this using a honing steel.  After a while though, you need to sharpen the knife again.  Another setting: If you have a brittle knife and/or mistreat your knife you will chip it.   As far as I can tell, this should mean that small pieces of metal (dust, shavings, etc.) come lose, and then likely get in the food.  Is this correct? Are there no health considerations when digesting small pieces of very sharp metal?
88844
I recently purchased a new soldering station (Aoyue 936). This is my first relatively good quality soldering tool, so I want to ensure I maintain it properly.  My question relates to tinning the tip once I am done using it. The manual which came with my product says:  "When you are not using your iron, make sure you leave a large lump of solder on the tip. This maintains the tinning of the tip, and the tip will last much longer."  However, after substantial reading around the internet, I can't find any such suggestion for tip maintenance. So my question is, when I'm done soldering and am putting it away for storage, do I simply melt a big glob of solder on the tip and put it away, or melt solder on the tip, wipe it off on the sponge, and then store it.  Note: When I try the latter method, the tip initially looks shiny, but after a minute, it gains a slight copper colored tint.