digitizer static problem

[Dispatcher85]

Hey guys have a weird question for you. Our dispatch is equipped with a digitizer for box alarms. Seems of late that when someone touches the system to send out the alarm, static electricity from the dispatches finger shock the system and shut it down. At this time the system has to be rebooted causing a delay is stricking the box. Any suggestions to alleviate the static.

Thanks Corey

[nmfire10]

I can't resist... Since it is probably from your clothing rubbing on the chair, I suppose working without clothes would fix it

Is this digitizer thing-a-ma-bob grounded? You can always touch something else metal before touching the digitizer, like a piece of the desk or a lamp or something.

[Dispatcher85]

I there something like a static mat or something that we can put near the digitizer to stop the problem.

[MassFD]

When we has static discharge problems in our office we found it was due to low humidity. We had had several radio consoles damaged as well as various other equipment that would reboot when touched. This went on for 3 winters before we connected it with low humidity. All equipment was already grounded to a common 8ga ground that runs thru the console.

We have since added a humidifer as well as a metal edge to the dispatch console that is grounded thru a 2.2 meg ohm resistor. On a cold day the humidifer puts over 8 gal of water in the air over 24 hours, even with that much water being added the humidty indicator that we put on top of the console reads ERR as the humidity is below it's senseing range.

The metal console edge still draws a Zap once in a while but we have not lost any equipment or had any random reboots since we began controling the humidity.

[Jim202]

Your not the first person to discover just how dry an air conditioned room can get in the winter time. Most computer centers have the air conditioning equipment installed with a built in humidifier.

Depending on what type of air conditioning system you have, it may or may not be able to have a humidifier added. If you took the cheap way out and use an in the wall or window unit, you SOL.

The room with electronic equipment must be maintained above 45% to prevent any static build up of people moving around. Some facilities even put in an anti static tile on the floor. If that is what was installed, a special wax needs to be used with it. If reqular floor wax has been used on the anti static tiles, it needs to be stripped off and only the special anti static wax used.

The type of clothing worn by the staff also makes a big difference. Many computer centers ban the females from wearing any nylon or silk clothing. This type of clothing tends to generate large amounts of static.

Rubber soaled shoes also tend to allow people to build up a charge walking over a tiled floor. Best shoes are older leather with the old type nails in the soles.

Jim

[Dispatcher85]

How about static spray anyone familiar with it. I know I have alot of questions but, I am new to all of this.
Corey

[MassFD]

Tryed the Static Spray, did not do a thing.

You have got to get the humidity up. As a first step I would get an inexpensive humidity indicator and see how low it realy is.

Does the problem go away during summer, if so then it is a low humidity problem.

By "digitizer" do you mean a digitize brand alarm aunucatior display. We have one of them also. We also had problems with it rebooting, it does a papertape printout of installed options on startup. takes 20 seconds or so.

[Dispatcher85]

Yeah, its a digitize brand alarm. I check the humidity in the room and it was 26.

[Wowbagger]

It sounds to me like the case of the device is not properly tied to ground, so when an ESD event occurs, rather than the charge being taken to ground by a ground line, it goes to ground through a signal line.

Try tying the case to ground with a ground strap. Use a GOOD ground - not just the center screw on the electrical power.

[kf4sqb]

Here's a "quick 'n dirty" humidifier for wall unit heaters/air conditioners. Put an old coffee can, or something similar, on top of the unit. Next, drape a rag of some sort over the side, so that one end of the rag goes to the bottom of the can, and the other hangs in front of the "conditioned air" outlet. Then, keep the can full of water. I don't know exactly how much this raises the humidity, but it will at least raise it enough that it doesn't dry your sinuses out so badly.

[Dispatcher85]

Wowbagger,

your the man. we tied the ground strap to the unit as you said and it works great. Thanks alot for the info.

Corey