Main Restorations Software Audio/Jukebox/MP3 Everything Else Buy/Sell/Trade
Project Announcements Monitor/Video GroovyMAME Merit/JVL Touchscreen Meet Up Retail Vendors
Driving & Racing Woodworking Software Support Forums Consoles Project Arcade Reviews
Automated Projects Artwork Frontend Support Forums Pinball Forum Discussion Old Boards
Raspberry Pi & Dev Board controls.dat Linux Miscellaneous Arcade Wiki Discussion Old Archives
Lightguns Arcade1Up Try the site in https mode Site News

Unread posts | New Replies | Recent posts | Rules | Chatroom | Wiki | File Repository | RSS | Submit news

  

Author Topic: An embarrassing electrical question  (Read 1055 times)

0 Members and 1 Guest are viewing this topic.

HeadRusch

  • Trade Count: (0)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 596
  • Last login:September 02, 2006, 04:13:30 pm
  • ....Here you are all EQUALLY WORTHLESS...
An embarrassing electrical question
« on: May 15, 2003, 09:29:56 pm »
Ok..its been awhile since my electrical course in college...uh, how do I test for ground continunity using a Voltmeter?

<hide in shame>

I linked up all my grounds on my CP and am wondering how to test to make sure there aren't any shorts, for the life of me I can't remember how to use the cheap $10 voltmeter I bought.  Its Ohms for testing resistatnce right?  Errrrrr...

What do I set the voltmeter at (Ohms/Volts right, not amps) and then the black common lead.  one end to one wire (going to IPAC) one other end to last lead in the chain.

Uh, right? :)

ie: Need instructions on how to use $10 voltmeter...<sob....>

".....its like a Koala crapped a rainbow in my brain!"

Druin

  • Trade Count: (0)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 180
  • Last login:May 10, 2009, 02:30:37 am
  • I'm a llama!
Re:An embarrassing electrical question
« Reply #1 on: May 15, 2003, 09:33:18 pm »
Put it on ohms and make sure the circuit is not powered (Ipac/whatever else) (can't measure resistance in a powered circuit) and then put a probe on each end of what you want to check for continuity.

If the cheap meter has a diode checker, that may provide a beeping continuity measurement too but looking for resistance is the same....

So you want to make sure you measure almost zero ohms.  A few ohms is expected.

If the connection you're checking is open (not connected somewhere), the resistance will be infinitely high, or show some error on the meter, however it is set up. Mine shows "OL" if it's open.  

To check for shorts between two points, if you see the low resistance between two points, it's shorted.
« Last Edit: May 15, 2003, 09:34:42 pm by Druin »

rampy

  • *shrug*
  • Trade Count: (+1)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 2910
  • Last login:March 02, 2007, 11:32:16 am
  • ...as useless as a JPG is to Helen Keller
    • Build Your Own PVR
Re:An embarrassing electrical question
« Reply #2 on: May 15, 2003, 09:36:29 pm »
ohms my man.. ohmeter...

You'll get 0 or near 0  like .001  -  .004 or the like ohms of resistance when the loop of wire(s) is good/closed  i.e. continuity.


if there is an 'open" you'll get "infinity" ohms or a really really high number or possibly an "out of range'

depending on the multimeter...

*srhug*  you shoulda got one that beeps when there's continuity =P  (i wish mine did)

good luck

rmapy

Valence

  • Trade Count: (0)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 151
  • Last login:June 15, 2004, 10:44:49 pm
  • I want my own arcade controls!
Re:An embarrassing electrical question
« Reply #3 on: May 15, 2003, 09:40:54 pm »
I wouldn't test continuity with the wires connected to the ipac but you are correct about the ohms.

Also you are looking for opens not short when checking for continuity.

To check for shorts (I'm assuming you mean a short from a hot wire to ground) You would put 1 lead on a hot wire (potential hot wire. don't check resistance when its powered)
and the other on the ground. Which lead you use doesn't matter.

Valence