That's not anti-static foam - first rule of MOSFETs: full anti-static precautions are required - if that's how the shop sold them that was a huge red flag, the devices could easily have been zapped already.
Maybe this article can shed some more light. It's the current that kills, but the current that runs through the body is dependent on voltage and resisance and especially the latter varies a lot depending on the circumstances. It also varies on the path it takes, through the heart is far more dangerous than (e.g.) into a finger and out the elbow. Time is another important factor.
Other than with very low voltages, it's hard to say when one becomes lethal.
In the article, there's a table of currents and reactions. As a young man I received a shock that went from one hand through to the other, so going through the heart. Based on what I remember, it must have been in the 6-30 mA range. Also, I remember not tripping the 30 mA RCD. That was a rather unpleasent experience that I remember for the rest of my life.
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Thanks. However, that's just yet another website that Google would also tell me about. What I am looking for is a well substantiated text from a reputable source. When it comes to information about safety and potentially lethal consequences I'd prefer something a bit more than just yet another website with ads and comic movies.
^ I'm not familiar with this work, but a quick review of the scope of work/synopsis brings this to the forefront as something to consider reading. It may help answer a few questions and lead toward additional resources depending on how deeply you'd like to delve into the subject.
https://www.ncbi.nlm.nih.gov/books/NBK448087/
https://www.ncbi.nlm.nih.gov/books/NBK448087/
Okay,
My official training. Keep your left hand in your pocket. Discharge power supplies, not just off, discharge capacitors and any CRTs. Don't stand in the water.
I'm serious, that was the training. As jitter said, there are so many variables. You can get a heck of a shock at 12 VDC due to inductive kick when something gets disconnected. I did work in the Telecom field, tip and ring guy, as well as DSL (that'll hurt!). My butt set would detect DSL for that reason and others.
I have been shocked by >25 KV (I hate TVs, I didn't even have to touch anything), 1.5 KV a couple times, 450 VDC (about) a few times and 120 VAC many times. Mostly due to circuit failures and voltage showing up where it wasn't supposed to be. My takeaway? Never assume anything.
But don't go looking for a chart. The most accurate information is the current chart. Voltage is highly variable and the current path means everything. Often the injuries sustained by involuntary muscle movement causes more physical damage than the shock, like gashes, scrapes and falls. So there is another dimension to what harm can come from electricity
My official training. Keep your left hand in your pocket. Discharge power supplies, not just off, discharge capacitors and any CRTs. Don't stand in the water.
I'm serious, that was the training. As jitter said, there are so many variables. You can get a heck of a shock at 12 VDC due to inductive kick when something gets disconnected. I did work in the Telecom field, tip and ring guy, as well as DSL (that'll hurt!). My butt set would detect DSL for that reason and others.
I have been shocked by >25 KV (I hate TVs, I didn't even have to touch anything), 1.5 KV a couple times, 450 VDC (about) a few times and 120 VAC many times. Mostly due to circuit failures and voltage showing up where it wasn't supposed to be. My takeaway? Never assume anything.
But don't go looking for a chart. The most accurate information is the current chart. Voltage is highly variable and the current path means everything. Often the injuries sustained by involuntary muscle movement causes more physical damage than the shock, like gashes, scrapes and falls. So there is another dimension to what harm can come from electricity
I can only tell you that in my training to become a technician for a district net operator (DNO) the only hard values that are given are minimum acceptable distances between you and a (bare) live conductor with only the air as an insulator, and even those values are called guidelines.
Those values (DL for 'minium acceptable distance in air defining the outer limit of the live working zone' and DV for 'minium acceptable distance in air defining the outer limit of the vicinity zone' are derived from EN 50110. For (e.g.) 10 kV they are 120 mm and 1150 mm. Below 1 kV, they are 'no contact' and 300 mm.
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Same question i have. Vendors like alixpress full of such silver faced 'philips' to92 transistors. Not sure about their authenticity.
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If they're from early 90's, i guess not. Everything depends on the source & good measurements.I didn't take any risk and bought ONsemi(FC) BC series instead.
Slightly OT - I searched around the forums before asking this. Is there a general repository for anecdotal feedback on suppliers / stores / websites?
As an example, I had a very recent interaction with a company that I admit had me fooled even after a reasonable, but clearly not extensive / exhaustive amount of diligence. They're either so poorly managed on the positive side or a complete fraud on the negative side. I don't know if it's proper or fits within rules (and I could see it getting out of control), but it would be really nice to have a "watch list" of sorts if it doesn't exist. Thoughts / pointers / links are appreciated.
As an example, I had a very recent interaction with a company that I admit had me fooled even after a reasonable, but clearly not extensive / exhaustive amount of diligence. They're either so poorly managed on the positive side or a complete fraud on the negative side. I don't know if it's proper or fits within rules (and I could see it getting out of control), but it would be really nice to have a "watch list" of sorts if it doesn't exist. Thoughts / pointers / links are appreciated.
Not every single component sold on Ali is fake. Those may indeed be BC548’s from 1999. Whatever it is, the seller got it cheap. The questions you have to ask is, 1. Is it possible to get them cheap and have them be real? 2. Are you willing to take the chance buy and try? 3. Does it even matter in your application?
Any serious professional user would answer NO to all 3. Your mileage may vary.
Hi ItsAllInMyHead,
Well, that could easily become a mess with folks who were simply not happy with a vendor. Not everyone is objective and professional.
I have an easy answer. I deal with authorized distributors selling current parts. Occasionally I need something NLA, then I buy from other service people I KNOW used legit parts.
Occasionally the only way forward with parts is to buy from a second source manufacturer, which I hate doing. Another source is harvesting old parts from another unit with the customer's permission. You are not allowed to sell used parts as new.
If possible, you are way further ahead when you intelligently substitute a part with a current one from authorized distribution.
Well, that could easily become a mess with folks who were simply not happy with a vendor. Not everyone is objective and professional.
I have an easy answer. I deal with authorized distributors selling current parts. Occasionally I need something NLA, then I buy from other service people I KNOW used legit parts.
Occasionally the only way forward with parts is to buy from a second source manufacturer, which I hate doing. Another source is harvesting old parts from another unit with the customer's permission. You are not allowed to sell used parts as new.
If possible, you are way further ahead when you intelligently substitute a part with a current one from authorized distribution.
^ 100% agreed on all counts.
However, many of us blur that line between "need" and "want" all too often.
Anecdotally - The nicest thing for me is (as of yet) when I've posted that I'm seeking a particular part for a particular project that is proven ready to go (vs. seeking parts to store/hoard or resell) ... I've always received a very nice PM from members willing to share at very reasonable costs. When possible, I try to pay it forward, but my "parts stash" only started a few years ago.
Thanks as always. Probably best not to open that can of worms with a "list".
However, many of us blur that line between "need" and "want" all too often.
Anecdotally - The nicest thing for me is (as of yet) when I've posted that I'm seeking a particular part for a particular project that is proven ready to go (vs. seeking parts to store/hoard or resell) ... I've always received a very nice PM from members willing to share at very reasonable costs. When possible, I try to pay it forward, but my "parts stash" only started a few years ago.
Thanks as always. Probably best not to open that can of worms with a "list".