He travels for work and can be away for a month or more. I bought 5 or 6 times from him, always got the right parts and good service when he's around. He doesn't seem to answer emails when he's away - don't know if he has access where he goes, so be a little patient -
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waiting for parts
FYI I bought from Zhou back in July. received partial shipment (he forgot 4 x4matched =16 IRF610 fets). emailed me on July 22 that he remembered packing them just must have left them somewhere, and that he would ship them two weeks later after returning from a business trip. Well now is mid September and i still have not heard or received from him. still hoping though...(but makes me wonder how well they are matched if he is so busy to begin with). may have to measure them all again before using. cheers, S.
FYI I bought from Zhou back in July. received partial shipment (he forgot 4 x4matched =16 IRF610 fets). emailed me on July 22 that he remembered packing them just must have left them somewhere, and that he would ship them two weeks later after returning from a business trip. Well now is mid September and i still have not heard or received from him. still hoping though...(but makes me wonder how well they are matched if he is so busy to begin with). may have to measure them all again before using. cheers, S.
I also have pending a resolution of a wrong component shipment....for months now.
email and 2 PMs not answered.
It's a loss for us all.
email and 2 PMs not answered.
It's a loss for us all.
NOT NICE
He still owes me a matched pair of Toshibas as far as I am concerned (in exchange for 16 matched IRF610s on which I could no longer wait so I bought them and matched myself). he is on ebay and i am really upset for the fact that i did not claim a problem through payPal since I trusted the guy and wanted to accomodate him even if late. 😡
He still owes me a matched pair of Toshibas as far as I am concerned (in exchange for 16 matched IRF610s on which I could no longer wait so I bought them and matched myself). he is on ebay and i am really upset for the fact that i did not claim a problem through payPal since I trusted the guy and wanted to accomodate him even if late. 😡
What happened to him? I've PMed him several times now and no answer?
Anyone have any luck reaching him?
Anyone have any luck reaching him?
ESD Safe Handling Packaging?
A friend over in New Zealand just bought some 2SK170 and 2SK369 FETS off this guy.
The FETs are genuine, but NO ESD Safe Packaging was used, the parts were just wrapped up in plastic bubble wrap.
The ESD labelling on the TOSHIBA boxes isn't there because they just wanted to print something in a blank space...
What gives? Everyone knows JFETS and MOSFETs are very, very, very sensitive to ESD, and that handling precautions are really, really important!
The problem with ESD damage to semiconductors is that it can take months for the damage to appear.
Over time your low noise JFETs are no longer low noise. And eventually fail - bugger
I was thinking of buying some too, but now I'm having second thoughts!
A friend over in New Zealand just bought some 2SK170 and 2SK369 FETS off this guy.
The FETs are genuine, but NO ESD Safe Packaging was used, the parts were just wrapped up in plastic bubble wrap.
The ESD labelling on the TOSHIBA boxes isn't there because they just wanted to print something in a blank space...
What gives? Everyone knows JFETS and MOSFETs are very, very, very sensitive to ESD, and that handling precautions are really, really important!
The problem with ESD damage to semiconductors is that it can take months for the damage to appear.
Over time your low noise JFETs are no longer low noise. And eventually fail - bugger
I was thinking of buying some too, but now I'm having second thoughts!
Cont'd ESD Packaging
According to the Triboelectric scale, plastic (e.g. bubble wrap) and cardboard (paper)are the last two things you want to rub together...
The FEST come packaged on a paper tape and the bubble wrap rubbing against them will generate a great amount of voltage
I just got these photos from my mate of the packaging used: It's very poor by industry standards...
Please Mr Fang invest in some ESD safe handling procedures and ship your parts in "proper" ESD Safe packaging!
That way you''ll save us all a lot of hair pulling when we are trying to figure out why our input stage(s) have gone noisy...
Thanks.
According to the Triboelectric scale, plastic (e.g. bubble wrap) and cardboard (paper)are the last two things you want to rub together...
The FEST come packaged on a paper tape and the bubble wrap rubbing against them will generate a great amount of voltage
I just got these photos from my mate of the packaging used: It's very poor by industry standards...
Please Mr Fang invest in some ESD safe handling procedures and ship your parts in "proper" ESD Safe packaging!
That way you''ll save us all a lot of hair pulling when we are trying to figure out why our input stage(s) have gone noisy...
Thanks.
Attachments
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well, you are not flying to the moon with these, so it may not be that serious...is it
I just keep mine away from the PC screen etc
and remember to water my hands before handling them 😀
but could still take days before they are solder properly and connected ground
yet they seem pretty tough
I have put one through all sorts of 'mishandling'
many times I thought 'that was that, its gone, lost'
but its still working
I find it hard to believe they are so fragile
I just keep mine away from the PC screen etc
and remember to water my hands before handling them 😀
but could still take days before they are solder properly and connected ground
yet they seem pretty tough
I have put one through all sorts of 'mishandling'
many times I thought 'that was that, its gone, lost'
but its still working
I find it hard to believe they are so fragile
ESD Precautions
It's serious, I want my circuit to work or fail because of my design, not because some part is at fault.
I also want to know if I blew up my circuit because of bad circuit design not because some ESD damaged part goofed me up!
I take it when you ask a question like "..it can't be that serious..." you come from non Electrical Engineering background?
I had ESD safe handling and precautions drummed into me all through University and then at the company I work now, you can get fired for not complying with the ESD handling procedures and policies...
With ESD damage you can spend hours trying to figure out why things aren't working.
Bad ESD handling practices cost a company I used to work for AUD100k's due to re-work, lost customers etc.
I'd love to hear you put that question to someone in the industry?
If you want to know more about ESD, check out the ESD Journal. Yes a whole journal focused on ESD safe handling and packaging: ESD Journal - Home
If you want to know more about "TRIBOELECTRICICATION": see attached
It's serious, I want my circuit to work or fail because of my design, not because some part is at fault.
I also want to know if I blew up my circuit because of bad circuit design not because some ESD damaged part goofed me up!
I take it when you ask a question like "..it can't be that serious..." you come from non Electrical Engineering background?
I had ESD safe handling and precautions drummed into me all through University and then at the company I work now, you can get fired for not complying with the ESD handling procedures and policies...
With ESD damage you can spend hours trying to figure out why things aren't working.
Bad ESD handling practices cost a company I used to work for AUD100k's due to re-work, lost customers etc.
I'd love to hear you put that question to someone in the industry?
If you want to know more about ESD, check out the ESD Journal. Yes a whole journal focused on ESD safe handling and packaging: ESD Journal - Home
If you want to know more about "TRIBOELECTRICICATION": see attached
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Ignorance is bliss, until it hits you in the face at 100 Mph.
ESD is real, and companies spend millions of dollars on setting up safe ESD working environments...it's no laughing matter
You might find the attached helpful in understanding ESD.
While the training doc focuses on CCDs, the same principles are valid for any semiconductor device, especially IGBTs, MOSFETs, JFETs, BJTs etc, etc etc
Often you can ESD damage a device and you don't even know it, the human body only starts to feel ESD when the voltage gets around 2.5 kV. At 100V or more, you have wrecked most JFETs if you have touched them and been charged up at the time.
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Toshiba's "Handling Guide for Semiconductor Devices,"
For reference, here's Toshiba's "Handling Guide for Semiconductor Devices"
TOSHIBA made the 2SK170 and 2SK369
This comes form their data book on FET and BJTs etc
For some lighter reading on the topic check out: http://www.radio-electronics.com/info/circuits/esd/electronics-esd.php
For reference, here's Toshiba's "Handling Guide for Semiconductor Devices"
TOSHIBA made the 2SK170 and 2SK369
This comes form their data book on FET and BJTs etc
For some lighter reading on the topic check out: http://www.radio-electronics.com/info/circuits/esd/electronics-esd.php
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your life doesnt depend on it
but if you produced medical equipment it might
or perhaps if you were about to produce hundreds of units to sell all over the world
and your company would depend on it
then yes
but honestly, this is a hobby, and we are doing it for fun, or whatever it is
if it fails it fails, so what
ok, basicly you are right, ofcourse
but in reality, how many here have the right equipment anyway
earth wrist wire, safety floor matt, secured solder station, etc
not to forget, you are just yourself, and able to control your own environment
in production you have many people running around, doing all sorts of things
a quite different situation that needs more rules, and precautions
but if you produced medical equipment it might
or perhaps if you were about to produce hundreds of units to sell all over the world
and your company would depend on it
then yes
but honestly, this is a hobby, and we are doing it for fun, or whatever it is
if it fails it fails, so what
ok, basicly you are right, ofcourse
but in reality, how many here have the right equipment anyway
earth wrist wire, safety floor matt, secured solder station, etc
not to forget, you are just yourself, and able to control your own environment
in production you have many people running around, doing all sorts of things
a quite different situation that needs more rules, and precautions
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