Author Topic: How should I protect from electrostatic charges?  (Read 1514 times)

0 Members and 1 Guest are viewing this topic.

Offline Doctorkong

  • Contributor
  • Posts: 18
  • Country: it
Re: How should I protect from electrostatic charges?
« Reply #25 on: July 05, 2018, 10:24:10 am »
What's the reason why a CR battery, covered by a plastic shell like that one, can drain its power if the cartridge is closed in an ESD bag?
All types of cell have some level of self-discharge, even if they are still sealed in their original packaging. The chemical energy is slowly wasted in side reactions that do not produce an external current. The exception is if some of the chemicals are left out, for example, a lead-acid battery shipped dry to the user, or a zinc-air cell with a sticker sealing the air holes.

Ok I got it. My question is: why does the ESD bag can accelerate the process of draining energy?
 

Offline JS

  • Frequent Contributor
  • **
  • Posts: 944
  • Country: ar
Re: How should I protect from electrostatic charges?
« Reply #26 on: July 05, 2018, 02:02:22 pm »
Resistive material, resistive absorbes energy and turn it into heat, high resistivity limits the current so it can damage anything.

Let's say your part inside the bag is charged with 10kV respect to you, like the plates of a cap, then it conducts slowly dissipating that energy, so for the time you are taking the part out of the bag it's at the same potential you are. If you are grounded to start with as all your equipment and desk there is no more charge to damage anything.

Anti static bags have a inner conductive layer so external spikes can't penetrate and damage parts, if only a high resistivity layer is present like in static dissipative bags external charges can penetrate directly into the part and damage it anyway. Dave has a video demostrating this with a ESD gun, frying components in pink bags while the ones in the grey bags suevive without much trouble.

JS

If I don't know how it works, I prefer not to turn it on.
 

Offline McBryce

  • Super Contributor
  • ***
  • Posts: 1260
  • Country: de
Re: How should I protect from electrostatic charges?
« Reply #27 on: July 05, 2018, 05:35:12 pm »
Hi Doctorkong,
          I own quite a few old cartridges for several systems (although I wouldn't describe myself as a collector). Static damage would be an extremely unlikely event with these cartridges as the contacts are well protected from finger touching etc. The only time I've ever seen one being damaged was during connection/disconnection from the console, at which time you'll have removed the anti-static bag anyway. If they are in a box and not being handled, there is zero chance of them being damaged from static. The biggest longterm risk to these "newer" cartridges (the older ones only contained a single EPROM) are the electrolytic capacitors which can leak and eat away at the copper tracks.

McBryce.

Happy to know another cartridge owner! :) What do you do when you remove cartirdges from the console? Do you use some precautions?

I chuck them unceremoniously into a metal drawer under the table. The cartridges I have are from (sorted by age):

Atari 2600
Commodore 64
Atari XL/XE
MSX
Amstrad CPC+
Gameboy
Gamegear

Nothing rare or valuable though. I've only ever had one cartridge that failed which was for the Atari XL/XE and it seems to be corrupted data in a OTP ROM. The IC was still readable, so static is unlikely to have been the cause.

McBryce.
 

Offline Doctorkong

  • Contributor
  • Posts: 18
  • Country: it
Re: How should I protect from electrostatic charges?
« Reply #28 on: July 05, 2018, 10:15:38 pm »
Resistive material, resistive absorbes energy and turn it into heat, high resistivity limits the current so it can damage anything.

Let's say your part inside the bag is charged with 10kV respect to you, like the plates of a cap, then it conducts slowly dissipating that energy, so for the time you are taking the part out of the bag it's at the same potential you are. If you are grounded to start with as all your equipment and desk there is no more charge to damage anything.

Anti static bags have a inner conductive layer so external spikes can't penetrate and damage parts, if only a high resistivity layer is present like in static dissipative bags external charges can penetrate directly into the part and damage it anyway. Dave has a video demostrating this with a ESD gun, frying components in pink bags while the ones in the grey bags suevive without much trouble.

JS

Ok, got it. But if the bag isn't in direct contact with the battery, how can the battery be drained? From what I know low voltages need to be in contact to another conductive material to generate the flux of electrons (so electricity). Sorry for all of these questions but since I know just a few physics is interesting to know more about.
 

Offline JS

  • Frequent Contributor
  • **
  • Posts: 944
  • Country: ar
Re: How should I protect from electrostatic charges?
« Reply #29 on: July 05, 2018, 10:19:20 pm »
Draining the battery wasn't the bag alone, but protdcting the fingers shorting them, discarded that idea battery behaves as designed.

JS

If I don't know how it works, I prefer not to turn it on.
 

Offline Doctorkong

  • Contributor
  • Posts: 18
  • Country: it
Re: How should I protect from electrostatic charges?
« Reply #30 on: July 06, 2018, 09:12:13 am »
Draining the battery wasn't the bag alone, but protdcting the fingers shorting them, discarded that idea battery behaves as designed.

JS

I'm sorry. I tried to understand what it means but I couldn't understand what you said :(
 

Offline JS

  • Frequent Contributor
  • **
  • Posts: 944
  • Country: ar
Re: How should I protect from electrostatic charges?
« Reply #31 on: July 06, 2018, 11:02:54 am »
With the anti-ESD bags there is no problem, if you add something conductive touching the fingers you could drain the battery, as someone said the fingers are protected already as they are designed as a outside world interface, you only need the whole thing to not be at 20kV when you first touch it. Bag is enough, no problems, not drained battery.

JS
If I don't know how it works, I prefer not to turn it on.
 

Offline Doctorkong

  • Contributor
  • Posts: 18
  • Country: it
Re: How should I protect from electrostatic charges?
« Reply #32 on: July 06, 2018, 09:03:58 pm »
With the anti-ESD bags there is no problem, if you add something conductive touching the fingers you could drain the battery, as someone said the fingers are protected already as they are designed as a outside world interface, you only need the whole thing to not be at 20kV when you first touch it. Bag is enough, no problems, not drained battery.

JS

Thank you, you were very gentle, like all the people here. I found a very great community.
So, if I use the ESD bag I should just check leaking from capacitors during the years and my cartridge is safe. Right?



 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf