RE: PC & static charges

[Vorn]

Do electrostatic air cleaners or negative ion generators pose any threat to home PC? I've heard one must use antistatic mat, wristbands, etc., when opening a PC case (which I never intend to do), but I will be using 'mobile-racks' to switch hard disc drives, and 'docking station' for HDD backups. Are the aforementioned air purifiers any threat?

[studiot]

Posted at 10.32, offline at 10.33 ?

 

Commercial computer environments are often air conditioned. Hard drives are not static sensitive, it is other computer components that you would need the paraphanalia for. Just observe sensible safety precautions like don't plug and unplug things live unless specifically designed that way.

[Delbert]

Do electrostatic air cleaners or negative ion generators pose any threat to home PC? I've heard one must use antistatic mat, wristbands, etc., when opening a PC case (which I never intend to do), but I will be using 'mobile-racks' to switch hard disc drives, and 'docking station' for HDD backups. Are the aforementioned air purifiers any threat?

Anti static precautions should be taken when dealing with any item of modern electronic equipment.

 

The distances between components and the components themselves within the those multi-legged components in most bits of kit these days, are absolutely miniscule. Such that any voltage above their normal operating limits are likely to cause stresses, if not breakdowns. Such voltages can be induced very easily by static if precautions are not taken.

 

For example, my bathroom light switch pull cord is perhaps an example. Whereby it normally hangs about an inch from the tiled wall, but on numerous occasions I find it diverted from the vertical with the plastic knob at the end stuck to the wall! And sometimes upon approaching it with my hand to operate the switch, it moves away! Static being the reason.

[CaptainPanic]

Do electrostatic air cleaners or negative ion generators pose any threat to home PC? I've heard one must use antistatic mat, wristbands, etc., when opening a PC case (which I never intend to do), but I will be using 'mobile-racks' to switch hard disc drives, and 'docking station' for HDD backups. Are the aforementioned air purifiers any threat?

The air purifiers should themselves be neutral, and grounded. (If this is not the case, and if you get an electric shock when you touch the outside of such a device, unplug it immediately, and take it back to the shop). Those devices should not be able to charge any other devices, certainly not a computer (which itself should be grounded or earthed through its power supply).

 

The reason you're supposed to be careful when opening the computer, it that the computer itself can carry charges (some components inside, mostly within the actual power supply). Some capacitors will build up some charges during normal usage of the computer, and they are not immediately dissipated when you switch off the computer. If your power supply to the computer is not earthed, then charges can also build up, especially if the air is very dry (dry winter days). To be safe, just unplug all the cables from a computer, (and if there is a main on/off switch, turn that off first). After that, it is generally safe to open the main casing of a desktop computer, for example to plug in additional RAM or a new harddrive. Mobile racks and docking stations are just more practical.

 

Delbert, that story about the pull cord of your bathroom light carrying charge is very frightening. I recommend that you have it checked out by a trained and certified electrician.

[Delbert]

Delbert, that story about the pull cord of your bathroom light carrying charge is very frightening. I recommend that you have it checked out by a trained and certified electrician.

Thanks for your concern, but it's static and nothing more. The cord is nylon and about 3.5 foot long, and depending on conditions the plastic knob at the end sometimes acquires a charge - perhaps just like those bits of polystyrene packaging that sometimes stick to things.

 

What did someone once say: you can generate a voltage higher that you can generate by charging a capacitor to the voltage you can generate and then pulling it apart.

 

Based on the formula: V = Q/C. Where V= volts, Q = charge in coulombs and C = capacitance in Farads.

 

Pulling the capacitor apart reduces C, and with Q remaining the same, V must increase. This is the principle of static build up. i.e. one can start with virtually no voltage at all and when the distance between suitable objects increase a miniscule voltage can increase to something noticeable.

[Vorn]

The air purifiers should themselves be neutral, and grounded. (If this is not the case, and if you get an electric shock when you touch the outside of such a device, unplug it immediately, and take it back to the shop). Those devices should not be able to charge any other devices, certainly not a computer (which itself should be grounded or earthed through its power supply).

 

The reason you're supposed to be careful when opening the computer, it that the computer itself can carry charges (some components inside, mostly within the actual power supply). Some capacitors will build up some charges during normal usage of the computer, and they are not immediately dissipated when you switch off the computer. If your power supply to the computer is not earthed, then charges can also build up, especially if the air is very dry (dry winter days). To be safe, just unplug all the cables from a computer, (and if there is a main on/off switch, turn that off first). After that, it is generally safe to open the main casing of a desktop computer, for example to plug in additional RAM or a new harddrive. Mobile racks and docking stations are just more practical.

 

Delbert, that story about the pull cord of your bathroom light carrying charge is very frightening. I recommend that you have it checked out by a trained and certified electrician.

 

Thanks for the info! I'll no longer worry that the air cleaners will do more harm than good.