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 Post subject: Multimeter questions
 Post Posted: Sat Jan 16, 2010 8:56 pm 
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COMPAQ- is the brand of computor-perhaps same as HP I don't know. Scott mentioned in his 18th. edition about useing a multimeter in testing voltages in a computor, is it a high Z model? I still have a V.T.V.M. that has a 100,000 ohm per volt impedance with a wheatstone bridge built in. most multimeters I have owned are rather low Z about 20,000 ohm per volt, which can load down a delicate system. _ carl


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 Post subject: Re: Vista and intenet explorer script errors
 Post Posted: Sun Jan 17, 2010 8:56 am 
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You can use any type of voltmeter on a computer. Old style analog ohm meters however (e.g. those with internal 9V batteries) should not be used on digital circuits. For measuring resistance, use a modern digital VOM instead. Scott.


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 Post subject: Re: Multimeter questions
 Post Posted: Sun Jan 17, 2010 6:38 pm 
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Dear Scott, I have a Digital meter that talks to me so I don't have to take my eyes off what I have the Probe on. It is also has a 7 Segment Liquad Crystal Display, I have never had it apart, so what powers the LCD if it does not have batterries or battery in it ?- Carl


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 Post subject: Re: Multimeter questions
 Post Posted: Sun Jan 17, 2010 8:05 pm 
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Your meter sounds fine, you just don't want one that uses 9V batteries. Scott.


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 Post subject: Re: Multimeter questions
 Post Posted: Mon Jan 18, 2010 12:31 pm 
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Dear Scott I see where you are coming from, Most resistors etc. are double rated in voltage etc. Back when I was being schooled in Tech School, I am not disagreeing , just stateing what I was taught, I agree that 3- 5 volt powered meter is safer, The V.T.V.M. only used a 1 1/2 volt battery= Thanks For your prompt and polite answers !- Carl


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 Post subject: Re: Multimeter questions
 Post Posted: Wed Sep 27, 2017 2:01 am 
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mildred wrote:
Your meter sounds fine, you just don't want one that uses 9V batteries. Scott.



scott Why don't you want to use a meter with a 9v batteries?


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 Post subject: Re: Vista and intenet explorer script errors
 Post Posted: Wed Sep 27, 2017 2:06 am 
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Scott wrote:
You can use any type of voltmeter on a computer. Old style analog ohm meters however (e.g. those with internal 9V batteries) should not be used on digital circuits. For measuring resistance, use a modern digital VOM instead. Scott.



What are digital circuits?
is a voltmemter same as a mutiltmeter?


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 Post subject: Re: Vista and intenet explorer script errors
 Post Posted: Wed Sep 27, 2017 10:28 pm 
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spiderman wrote:
What are digital circuits?

Digital circuits are binary circuits in a computer that typically work on switching 5V (or lower voltage) signals. Compare this to analog circuits, which use continuously variable signals of any voltage level.

Quote:
...is a voltmemter same as a mutiltmeter?

A voltmeter measures voltage. A multimeter measures voltage, current and resistance. Multimeters include a voltmeter.

Quote:
Why don't you want to use a meter with a 9v batteries?

Because only older (mostly analog) multimeters use 9V batteries and injecting 9V into a circuit that runs on only 3V or less may cause damage. Scott.


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 Post subject: Re: Multimeter questions
 Post Posted: Fri Oct 13, 2017 3:29 am 
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Quote:
Because only older (mostly analog) multimeters use 9V batteries and injecting 9V into a circuit that runs on only 3V or less may cause damage.

Now would this be also with a digital multimeters that use a 9v batteries as well.








have you seen a 9v batteries that is higher then 9v like 10v what is the deal with that. I test a new 9V battery and it shows as 10v on three meters....

weird...


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 Post subject: Re: Multimeter questions
 Post Posted: Fri Oct 13, 2017 8:44 am 
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spiderman wrote:
Now would this be also with a digital multimeters that use a 9v batteries as well.

Any digital multimeter would be fine no matter what battery it used.

Quote:
have you seen a 9v batteries that is higher then 9v like 10v what is the deal with that. I test a new 9V battery and it shows as 10v on three meters....

The zero-load voltage of an alkaline battery can be up to 1.65V. Since a 9V battery has 6 cells it can show a no-load voltage of up to 9.9V


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 Post subject: Re: Multimeter questions
 Post Posted: Fri Oct 13, 2017 3:44 pm 
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Scott. I have Radioshack Digital Auto Ranging Multimeter. It's Catalog no. 22-801. This is the only thing I could find on it. I still have the manual and everything. I don't remember when I purchased it but it does have a 9 Volt battery. I assume it's fine. I just opened it up today to check it out. I changed the battery and it seems to power up fine. Only remember using it once to try "back-probing" a PSU as described in your book.

I'm guessing you really miss RadioShack Scott.


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 Post subject: Re: Multimeter questions
 Post Posted: Fri Oct 13, 2017 8:30 pm 
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That meter should be fine. I have been a customer of Radio Shack since the early 1970s and even worked at a store for a short time in the early '80s. They are an American institution. While they are not gone they are not what they used to be (but neither is anything else): https://www.radioshack.com/


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