Dangers and Safety considerations. - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #1 of 14 Old 03-10-09, 03:01 PM Thread Starter
Plain ole user
 
lcaillo's Avatar
Tech Guru
 
Join Date: May 2006
Location: Gainesville, FL, USA
Posts: 11,121
Send a message via AIM to lcaillo
Dangers and Safety considerations.

It has been suggested that I have not emphasized the dangers of servicing electronics enough in these forums. There are, obviously, many ways in which working with electronics can be hazardous, so this thread will be dedicated to discussing these dangers and proper ways to mitigate them.

One excellent place to start and a suggested read for EVERYONE is:

http://www.repairfaq.org/sam/safety.htm




Looking for me, just google my username. I have used the same one for most sites for many years.
lcaillo is offline  
Sponsored Links
Advertisement
 
post #2 of 14 Old 03-10-09, 04:31 PM
Elite Shackster
 
tonyvdb's Avatar
Tony
 
Join Date: Sep 2007
Location: Edmonton, Alberta, Can
Posts: 15,054
My System
Re: Dangers and Safety considerations.

If I may,

One of the biggest dangers of working on electronics whether it be a TV, computer or receiver is that even though you have unplugged the power there are still very dangerous voltages present for even up to 4hrs after the incoming power has been removed.

Capacitors hold a very high voltage that can kill you. Capacitors are like a battery but will discharge all of its charge instantly if you touch the leads. Never assume that the voltage inside the hood is gone even after a short time.

Home theater:
Onkyo 805, Yamaha YDP2006EQ, Samson Servo 600 amp
3 EV Sentry 500 monitors across the front, 4 Mission 762i's Surrounds, SVS PB13U sub, Panasonic BDT220, Harmony 1100, Nintendo WiiU
Panasonic PT-AE8000 on a 120" 2,35:1 fixed screen

Living room system:
Sherwood/Newcastle R972, Mission 765's, SVS SBS02's, A/D/S MS3u sub, Yamaha YDG2030EQ
Yamaha KX-393 Tape deck, CDC 805 CD changer, Panasonic BD60, Sony turntable PS-T20
Panasonic TC-P50ST60, HD-PVR & WDTV Live, Harmony 900

tonyvdb is offline  
post #3 of 14 Old 03-10-09, 04:43 PM
Elite Shackster
 
robbo266317's Avatar
bigbadbill
 
Join Date: Sep 2008
Location: Newcastle Australia
Posts: 5,771
Re: Dangers and Safety considerations.

Also be aware that consumer electronics are only meant to be opened by trained personel.
A lot of equipment isn't earthed either, simply relying on "double insulation" to meet local approval ratings.
I recently opened my Pioneer VSX710 and was amazed that the mains terminals & selector switch were not covered in any way. It would be very easy to inadvertantly come in contact with them if you weren't careful.
robbo266317 is offline  
 
post #4 of 14 Old 06-14-09, 08:14 AM Thread Starter
Plain ole user
 
lcaillo's Avatar
Tech Guru
 
Join Date: May 2006
Location: Gainesville, FL, USA
Posts: 11,121
Send a message via AIM to lcaillo
Re: Dangers and Safety considerations.

Good links to understand capacitor charging and discharging:

http://hyperphysics.phy-astr.gsu.edu...ic/capdis.html

http://www.repairfaq.org/sam/captest.htm#ctsdc



Generally, capacitors can be safely discharged using a resistor (to chassis ground or between legs) of between 10 and 100 ohms per volt for the rated voltage of the capacitor. This will avoid damage to the capacitor by discharging too rapidly, as well as prevent dangerous and uncontrolled arcing.




Looking for me, just google my username. I have used the same one for most sites for many years.
lcaillo is offline  
post #5 of 14 Old 06-18-09, 08:06 AM
Senior Shackster
 
cavchameleon's Avatar
Ray
 
Join Date: Jan 2008
Location: Albuquerque, NM
Posts: 667
My System
Send a message via Yahoo to cavchameleon
Re: Dangers and Safety considerations.

Quote:
lcaillo wrote: View Post
Good links to understand capacitor charging and discharging:

http://hyperphysics.phy-astr.gsu.edu...ic/capdis.html

http://www.repairfaq.org/sam/captest.htm#ctsdc



Generally, capacitors can be safely discharged using a resistor (to chassis ground or between legs) of between 10 and 100 ohms per volt for the rated voltage of the capacitor. This will avoid damage to the capacitor by discharging too rapidly, as well as prevent dangerous and uncontrolled arcing.
Very good thread and advice. As far as discharging capacitors, it is a very well accepted practice in the custom stereo for auto industry as may have 'open' capacitors in the rage of 1 - 5 Farads (yes, that is correct, HUGE capacitors).

One other note I'd like to mention is that most equipment uses lead based solder (except for a few manufactures that are getting away from using lead). This can be a lot more toxic then one thinks, especially if handling it frequently. Venting of the work space to the outside (or through a system that's made to absorb fumes) should always be used - plus no eating while soldering until hands are washed. Heavy metals build up in the liver and are never release from the body. I've done my share of 'toxic' inhalation from a lot of past soldering (am very careful now).

Thanks for starting this thread! This should be noted in all DIY areas.

Ray

Ray


Happy Listening!!! Listen with an open mind and heart!!!
cavchameleon is offline  
post #6 of 14 Old 06-18-09, 12:37 PM Thread Starter
Plain ole user
 
lcaillo's Avatar
Tech Guru
 
Join Date: May 2006
Location: Gainesville, FL, USA
Posts: 11,121
Send a message via AIM to lcaillo
Quote:
cavchameleon wrote: View Post
Very good thread and advice. As far as discharging capacitors, it is a very well accepted practice in the custom stereo for auto industry as may have 'open' capacitors in the rage of 1 - 5 Farads (yes, that is correct, HUGE capacitors).

One other note I'd like to mention is that most equipment uses lead based solder (except for a few manufactures that are getting away from using lead). This can be a lot more toxic then one thinks, especially if handling it frequently. Venting of the work space to the outside (or through a system that's made to absorb fumes) should always be used - plus no eating while soldering until hands are washed. Heavy metals build up in the liver and are never release from the body. I've done my share of 'toxic' inhalation from a lot of past soldering (am very careful now).

Thanks for starting this thread! This should be noted in all DIY areas

Ray
Posted via Mobile Device

All new products use lead free solder. IME lead is far less of a hazard than suggested. I have worked with leader solder for 30 years and have been tested several times with negative results. I suggest reasonable care in using lead based solder, but it really is not great hazard. The fumes contain other hazardous substances but not lead.



lcaillo is offline  
post #7 of 14 Old 06-19-09, 08:02 AM
Senior Shackster
 
cavchameleon's Avatar
Ray
 
Join Date: Jan 2008
Location: Albuquerque, NM
Posts: 667
My System
Send a message via Yahoo to cavchameleon
Re: Dangers and Safety considerations.

Icaillo,

I want to thank you so much for sharing a LOT of info in so many threads!!! I'm still reading some of them, very thoughtfully put together with great incite and care! Much appreciated.

Ray

Ray


Happy Listening!!! Listen with an open mind and heart!!!
cavchameleon is offline  
post #8 of 14 Old 11-18-09, 03:03 PM
 
Join Date: Nov 2009
Posts: 2
Re: Dangers and Safety considerations.

If you need any help to read Electronics Engineering. just visit
Freelancer. com There you can find thousands of coders who are really very helpful on Mechanical Engineering. And use this unique 'TURBOCIRCUITS' word to get some extra feathers.
Have a nice time
bye
heba66 is offline  
post #9 of 14 Old 02-09-10, 05:00 AM
 
Join Date: Jan 2010
Posts: 22
Re: Dangers and Safety considerations.

The capacitors are like a battery but will discharge all of its charge instantly if you touch the leads.
subzero is offline  
post #10 of 14 Old 02-09-10, 05:42 AM Thread Starter
Plain ole user
 
lcaillo's Avatar
Tech Guru
 
Join Date: May 2006
Location: Gainesville, FL, USA
Posts: 11,121
Send a message via AIM to lcaillo
Re: Dangers and Safety considerations.

Actually, a capacitor will discharge no differently than a battery. The rate of discharge depends on the voltage and the load attached to it. Capacitors can often have much higher voltages than batteries, but cannot deliver current for as long a period. With respect to safety, it is always wise to confirm that the larger caps in a device are discharged properly before working on the device.




Looking for me, just google my username. I have used the same one for most sites for many years.
lcaillo is offline  
Reply

Bookmarks

Tags
considerations. , dangers , safety

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome