Previous in Forum: Circuits   Next in Forum: Switching Power Supplies
Close
Close
Close
9 comments
Rate Comments: Nested
Active Contributor

Join Date: Sep 2008
Posts: 10

Analog and Digital

09/06/2008 12:02 PM

Analog and digital refer to the two ways electricity can what?

Register to Reply
This discussion was "closed" on 09/08/2008 2:03 PM. No new comments are allowed.
Message from admins:
homework - I know, it's kinda like closing the barn after the horse....
Power-User
Hobbies - HAM Radio - New Member United States - Member - New Member Hobbies - Hunting - New Member

Join Date: Jun 2008
Posts: 440
Good Answers: 7
#1

Re: analog and digital

09/06/2008 2:20 PM

Someone else will have to describe it for communications and audio.

Not to over simplify it--Digital is a yes or no--and when an electrical signal(doesn't matter what it's characteristics are) is present, it represents a 1 or yes and when it is gone a 0 or no.

Analog--The characteristics of the electrical signal matter --0 to 10 volt signal: 0=zero, 5= 50%, 10=100%, and so on. Current is some times used: 4-20 mA(Milliamps) Same thing is true and can be based on percentage. It can control a motors speed--4mA or less the motor is stopped--As you increase the mA signal the motors drive will increase it's speed. It can be used for positioning valves or cylinders.

There is a lot more to it than this.

__________________
Those who believe in telekinetics, raise my hand --Kurt Vonnegut Jr.
Register to Reply
Power-User

Join Date: Aug 2007
Posts: 479
Good Answers: 9
#2

Re: analog and digital

09/06/2008 7:46 PM

Each digital input signal to a gate is either high or low; base 2. The output from the gate depends on the inputs and the type of gate (AND, OR, NAND, XOR). Example output from AND gate is high if both Inputs are high, low if not. But output from an OR gate is high if either Input is high. The output from gate 1 can become the Input to Gate 2, etc, etc, etc.

An analog signal has a range of values (low to high) from 4-20 mA. Example (valve) position zero (closed) represent 4 mA while (valve) position 100% (fully open) represents 20 mA. The transmitter for this analog signal when calibrated can take any value between 4 and 20 mA and convert it to a (valve) position within its range (between 0 and 100%).

Signals outside the range (<4 mA or >20 mA) are out of range. The transmitter will report "BAD DATA". An "Instrumentation and Control" technician will need to be called to service the analog signal in this case. The analogy between the electronic signal and the mechanical valve position is not making sense (for example).

You may say, o.k. so analog is better then? Remember that today discrete gates (digital) are seldom used in practice. However an integrated circuit containing 1 million or more gates on a silicon chip the size of a finger nail can be programmed and used making digital signal processing practical.

Both methods (analog and digital) are widely used today.

When referring to signals, use the word electronics, not electricity.

When referring to power, use the word electricity, not electronics.

Power supply and signal source are very different concepts.

Register to Reply
Guru
Popular Science - Cosmology - Let's keep knowledge expanding Engineering Fields - Retired Engineers / Mentors - Hobbies - HAM Radio - New Member

Join Date: Dec 2006
Location: North America, Earth
Posts: 4528
Good Answers: 106
#3

Re: analog and digital

09/07/2008 12:28 AM

Pleaasee, get out your school books and start reading!

__________________
“I would rather have questions that can't be answered than answers that can't be questioned.” - Richard Feynman
Register to Reply
Power-User
Hobbies - Musician - New Member Engineering Fields - Manufacturing Engineering - New Member

Join Date: Sep 2007
Location: Endless Mountains of NE Pa, USA
Posts: 298
Good Answers: 20
#4

Re: analog and digital

09/07/2008 3:17 AM

Analog and digital refer to the two ways electricity can what?

a) Be measured by a VOM

b) Be used in a control circuit

c) Both of the above

d) None of the above

All of your posts sound like questions from a basic technical knowledge aptitude exam usually given by an employer.

If you are going to use the answers you gain here to just "fill in the blanks" of a test so you can be considered for an on-the-job training program or advanced courses offered by your employer.....Don't do it! You will be "found out" in a hurry. Hopefully before you can injure yourself or a co-worker.

At the very least, take some courses at a local college or technical school in the disciplines required for whatever it is you are trying to pursue. Or buy some books and learn some basics so you won't have to ask for the answers to such rudimentary questions.

Good general reference books to have on hand:

"Bushsbaum's Complete handbook of practical electronic reference data"

http://www.alibris.com/search/books/qwork/833511/used/Buchsbaum's%20Complete%20handbook%20of%20practical%20electronic%20reference%20data

"Practical electrical wiring"

http://www.amazon.com/Practical-Electrical-Wiring-Residential-Commercial/dp/0971977917

"Machinery's handbook"

http://www.amazon.com/s/?ie=UTF8&keywords=machinery%27s+handbook&tag=googhydr-20&index=aps&hvadid=1109102201&ref=pd_sl_9bh0gjicgc_b

__________________
Courage is not the absence of fear, but the inner resolve to rise above it....or the inane lapse in judgement brought on by copious imbibitions....Egre Flagrus
Register to Reply
Guru

Join Date: Feb 2006
Posts: 757
Good Answers: 12
#5

Re: analog and digital for teachers

09/07/2008 3:35 AM

I see you're still in a prankish mood. So my answer is: True....provided.

Register to Reply
Power-User

Join Date: Jun 2008
Location: Olive Branch, Ms. USA
Posts: 124
#6

Re: Analog and Digital

09/07/2008 6:15 PM

Please enroll in a vocational school or an apprenticeship program. If you can't even answer the most basic question on electrical theory, you pose a very real threat to ypourself, your co-workers, and the facility where you are employeed.

__________________
Tell 'em what they need to hear; not what they want to hear!
Register to Reply
Anonymous Poster
#7
In reply to #6

Re: Analog and Digital, What have they in common?

09/08/2008 5:15 AM

That's a bit dramatic, even for a Mississippi boy. 'Sides that, the question (and the other one) is not asking about "electrical theory."

Register to Reply
Anonymous Poster
#8

Re: Analog and Digital

09/08/2008 9:10 AM

hi sir
just to add something:
if you have 10vdc input and you want to control the output from 0-10vdc you can do it analog or digital.
analog is to place rheostat in the line, more ohms less output.
digital is to change the duty cycle?
duty cycle is to change the timing of the switching ''on-off''
when the duty cycle is 10% that mean the ''on'' time is 10% and ''off '' time is 90% and you will get output 10% of the input voltage.
when the duty cycle is 50% it means half the time ''on'' and half the time ''off '' and you will get output 50% of the input voltage and so on.
this digitally switching is occur at very high frequency.
when you switch on the input, the output will go from 0v to 10v quickly.
when the duty cycle is 10%, the switching OFF will occur faster and the output will cutoff when the input reach only 1v, so the output will be 1v and so on.

Register to Reply
Guru
United States - Member - New Member Engineering Fields - Power Engineering - New Member

Join Date: Sep 2006
Location: California, USA, where the Godless live next door to God.
Posts: 4665
Good Answers: 804
#9

Re: Analog and Digital

09/08/2008 1:55 PM

STOP POSTING YOUR HOMEWORK QUESTIONS HERE!

STOP ANSWERING THEM FOR HIM. THIS PERSON HAS POSTED NUMEROUS STUDENT QUESTIONS IN THE PAST WEEK IF IT CONTINUES TO SUCCEED, THEIS FORUM WILL GET FLOODED WITH STUDENTS TRYING TO GET THEIR WORK DONE FOR THEM AND WILL BECOME USELESS FOR ANYONE ELSE.

__________________
** All I every really wanted to be, was... A LUMBERJACK!.**
Register to Reply
Register to Reply 9 comments
This discussion was "closed" on 09/08/2008 2:03 PM. No new comments are allowed.
Message from admins:
homework - I know, it's kinda like closing the barn after the horse....
Copy to Clipboard

Users who posted comments:

Anonymous Poster (2); CowAnon (1); JRaef (1); Kilgore Trout (1); noshorts (1); snygolfgs (1); StandardsGuy (1); user-deleted-9 (1)

Previous in Forum: Circuits   Next in Forum: Switching Power Supplies
You might be interested in: Digital-to-Analog Converters

Advertisement