Anti-static protection

My iron is ESD safe, but I fried an emitter recently whilst handling because I wasn’t wearing my anti-static band. Annoyingly, it was my only spare XP-E. >.<

I saw this wireless anti-static wrist band on Ebay which seems ideal, not being tied to a grounding point by a short coil. But, do they really work? How do they work exactly?

Ive never heard of an LED emitter getting damaged from a static discharge. This makes me wonder how Ive avoided this scenario through so many mods. Can you tell us how it happened? Did the bond wires get vaporized?

Sorry to hear that, always the one you don’t have a spare for…

Those wireless bands are bull’s you know what :open_mouth: Supposed to use the voltage to create a corona or something like that. Nearly bought one myself some time ago, luckily checked up first.

Thanks, xmint.

Flashpilot, I was in a carpeted area whilst handling the LED to check some measurements. I can’t see any damage. It was working right before, and not working when I returned to the kitchen where my meter was, using diode test.

In the datasheets it does mention taking precaution. Oh well.

The ESD wrist band must be connected to ground to work. It has a high value resistor built in so it will drain off any static but won’t conduct enough current to harm you.
My workbench has an anti static mat. I should wear the wrist strap and connect it to the mat which is already connected to ground, but I live in a high humidity environment and don’t have to worry about static.

Wow. I can’t believe that hasn’t happened to me. My cat just crackles when I pet him.

I highly doubt it was esd. I’ve handled emitters hundreds of times with no esd protection while walking on carpet, shoes/no shoes, every possible scenario and never had this happen. Retrace your steps from the last time the led lit up.

Keep in mind that for esd to damage the emitter the discharge would have to travel THROUGH the led. Seems unlikely to say the least.

Ground straps do work, but I question their usefulness. I’ve been building and repairing computers for about 30 years and I’ve never worn a ground strap. Never fried a computer and I’ve actually tried. A few times I’ve taken my shoes off and walked around on the carpet specifically to get an ESD on a motherboard/CPU I didn’t care about and even with a nice, blue spark into a CPU on several occasions I still haven’t managed to fry a computer yet in all these years.

One of my friends used to be responsible for maintaining about a thousand computers. He did an experiment to see if he could fry computers by replacing components with the systems power on and he couldn’t fry one after a week of trying. He was pulling video cards out with computers that were turned on and sitting at the Windows desktop. The monitor makes some purdy colors when you do that.

I have made computers and other electronics reset with inadvertent ESDs though. We get a lot of wind during the summer and it feels like being the mayor of Sparkville a couple months out of the year.

That’s FUNNY, right there!!

The purpose of the wrist straps we wear is to provide a path from your body to a safe Ground through which the accumulation of Charge on your body can be removed.

The wire implements that purported function.

No wire, no path to ground, no discharge. It’s one of those “laws”…

The inferred purpose of this dingus is to separate people who don’t understand electricity/physics from their money. Does it work? Not on me!

The one redeeming feature it has is inferred from the comment: “great for electrician”. This means the dingus’ wire won’t become the Path for an Arc Flash through an electrician. Saves lives!

You may have touched your LED on the + side, creating a large Reverse Voltage. Some Crees can take that, some cannot. ESD can generate huge voltages, just ask your cat. It takes a few thousand volts for you to feel the spark at all. How much Vr (or Vf for that matter) is your LED rated to handle?

PS: this isn’t necessarily a “bond wire” issue. The GaAs (or whatever it’s made of) can only stand a certain level before the material itself quits.

Generally speaking, when you move your feet (even fidgeting) touch metal. Be conscious of large bodies of metal around you & get skin-friendly with them on a semi-regular basis as you work & all should be well. Not that you need this warning, but be careful around the edges (especially with Apples) as the mfg. process leaves sharp “wire edges” which will filet your hands instantly & leave your work a bloody (literally) mess.

As to the people who abuse computers, there is no real voltage past the PS which will cause you much grief pulling cards & such, even if the card has a “finger” for that supply line. You can extract the piezo “snapper” from an electric-start lighter & use it to shoot sparks on stuff… When I did that, it worked perfectly to kill CMOS devices on a motherboard.

EDIT: PS: If you want to see how bad it really is, try to measure the ESD voltage (when you’re playing Mr/Ms Sparky with the cat) with your DMM… (Don’t waste your best meter on this!) When you’re done, I may be able to repair it for you.

80% RH here, with 100% come and goes.

What’s this ESD kajigger you guys talking about? :stuck_out_tongue:

They tell new technicians to put one of your hands on the power supply or at least periodically touch it if you don’t have a ground strap.

I do all my mods while sitting in a bathtub full of water. Plumbing is often an ok way to tap into a ground, if your house doesn’t have electricity run to it. But then, I guess you wouldn’t be soldering.

I just do my mods barefoot in my back garden.

Not dropping anything is important. I’ve lost more LEDs and parts in my bed of tomatoes then I can count.

Makes for a fun night time harvest though.

That’s the best way to test a Flyback Transformer on an old CRT, BTW… Slip a solid-metal butter knife under the rubber cup & HANG ON!

Of course, the result won’t be “tapping” into the ground. “NAPPING” would be more like it… :insert emoticon for gruesome leer:

There isn’t much metal around to touch that isn’t painted/coated. I usually get a shock from the screws holding in the light switch. I guess I could use these screws as a contact point for my wrist band, if I made the lead longer.

It probably doesn’t help, wearing polyester mix and other synthetics. I have been lucky with computer equipment so far, touching the case whilst working.

I hate static shocks. Sometimes I just seem to be more charged. >.< My current vacuum cleaner is terrible for shocks too.

I know someone who fried some laptop memory trying to install it without grounding himself. It’s possible.

Personally, I don’t use any anti-static protection when working on flashlight LEDs or driver boards. I wouldn’t try working on LEDs right after giving my cat a vigorous pet though.

The wife actually saw me spark her laptop memory when I was upgrading it. She made a snarky comment that if I fried it, then the 20 bucks for the new memory stick would come out of my flashlight budget … doh!

A couple weeks ago I had to strip that same only-a-year-old HP Pavilion G7 laptop down to almost bare metal to replace the factory-defective CPU fan, which required removing the motherboard and dismounting the heatsink from the CPU. This time I didn’t spark it, but as usual I showed the components no love. I even handed her the completely stripped plastic shell back and said “here, I’m done—it’s even a little lighter now” :wink:

Not anymore. Plumbing is all plastic now.

Some time ago one could buy “anti shock” keychain attachments for 2€ or so. It was basically a couple of MegOhm big resistor in a appealing casing, allowing one to discharge before touching stuff. Maybe a worthwhile Investment. :smiley: (Or buy some ESD slippers for home, the perfect nerdgear :P)

For the computer parts: yeah, they got quite rugged in many cases.
Discrete electronic components is another thing though. LEDs (reverse), FETs (at the gate) etc you can still insta-kill with touching if unlucky.
Btw, many components might get somewhat damaged, but won’t show it necessarily with instant total failure. They’ll just die a little earlier. :wink:

I hate getting shocked too. Twice just today with all this wind. Getting in an out of the car is awful. What I do is turn and touch the car so that I take the shock on my bicep instead of my finger tips when I go to open the door. It still sucks. Our Chihuahuas don’t like it much either.