# Servo Minutes

Discussion in 'General Electronics Chat' started by DexterMccoy, Apr 15, 2014.

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1. ### DexterMccoy Thread Starter New Member

Feb 19, 2014
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I don't understand why on an API angle position indication that measure the degrees and Minutes

Why do you need to know the Minutes of a Servo or Synco Motor?

The Minutes tell you what?

I would think they would just need to know how many degrees and angle it is at

2. ### BillB3857 Senior Member

Feb 28, 2009
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It indicates a greater accuracy. One minute is 1/60th of a degree. 1 Second is 1/60th of a minute. SO, if the accuracy is expressed in minutes, it simply means it has more accurate resolution than one that can only break rotation down into degrees.

As a comparison a shaft encoder may have 100 pulses per revolution. Another may have 1000 pulses per revolution. Which would be more accurate?

3. ### DexterMccoy Thread Starter New Member

Feb 19, 2014
429
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There is Radians, degrees or Minutes

But some API meters are in Degrees and other API units are in Minutes

The Angular Range on the Display is 3 digits are in Degrees and 2 digits are in Minutes , why in minutes?

North Atlantic 8300 API unit manual

4. ### BillB3857 Senior Member

Feb 28, 2009
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360 degrees make one revolution, thus 3 digits. 60 minutes make 1 degree, thus 2 digits. Radians and degrees are just different ways to measure angles.

What geometry courses have you taken?

Oct 15, 2009
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6. ### DexterMccoy Thread Starter New Member

Feb 19, 2014
429
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None

But why not just keep is all the Degrees? why convert it to Minutes

Plus we aren't measure the synchos or servo motors Time, so why measure the Minutes of rotations , it should be kept in degrees

7. ### Wendy Moderator

Mar 24, 2008
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Because it is a very old standard you should have known. It is never too late to learn something new, this one has been around for a while. It is not a co-incidence that clocks and latitude and longitude have minutes and seconds, and relate very closely to angles and arc measurement.

8. ### GopherT AAC Fanatic!

Nov 23, 2012
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How do I set my GPS to radians?

9. ### DexterMccoy Thread Starter New Member

Feb 19, 2014
429
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True

Well some API units are displayed in degrees only , which is XXX.XX

other API units are displayed in degrees and minutes which is displayed with the First three digits in degrees and two in minutes

XXX.XX

The API examples are like 244 degrees at 15 minutes
or like 120 degree at 55 minutes
or like 60 degrees at 3 minutes

If They keep it all in degrees , without using the minutes, why would it be less accurate resolution

10. ### GopherT AAC Fanatic!

Nov 23, 2012
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It is "and", not "at".
as in 120 degrees and 15 minutes.

120 degrees and 15 minuets is the same as 120.25 degrees.

11. ### BillB3857 Senior Member

Feb 28, 2009
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It would be like keeping time on a clock with only the hour hand or a digital clock with only the hours displayed. Not very accurate, is it?

12. ### GopherT AAC Fanatic!

Nov 23, 2012
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It could be accurate with hundredths of an hour. 2.25 o'clock. Confusing but, since you have 1 part in 100, it could be more accurate than minutes (1 part in 60).

13. ### BillB3857 Senior Member

Feb 28, 2009
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True if you put 100 dash marks between each hour mark. Not exactly easy to read. Try that on a wrist watch.

14. ### DexterMccoy Thread Starter New Member

Feb 19, 2014
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So you guys are saying that minutes has more subdivisions then degrees?

15. ### BillB3857 Senior Member

Feb 28, 2009
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NO! A minute is a small part of a degree. A penny is a smaller part of a dollar. You really need to get a basic understanding of math, and units of measure in order to even begin understanding electronics. A house needs to have a foundation laid before building anything else.

16. ### DexterMccoy Thread Starter New Member

Feb 19, 2014
429
2
Ok i get that 1 minute is displayed in two digits on the API

But why is the API displayed in 5 digits, with 3 digits being degrees and two in minutes? why is it only 5 digits?

The two digital for minutes = 1 degree

So what ever the minutes are it will be = to 1 degree

Since the API is displayed with 3 digits in degrees and 2 in minutes
What is this called? Decimal degrees?

Because I'm having trouble adding and subtracting two different API measurement readings

API measurement
255 degrees at 15 mins + 63 degrees at 47 mins = ?
222 degrees at 31 mins - 21 degrees at 39 mins = ?

How can I add and subtract them because it's mixed with degrees and mins

17. ### BillB3857 Senior Member

Feb 28, 2009
2,400
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If it is 9:00 and I need to leave in an hour and a half, and it takes 45 minutes to drive to where I'm going, when will I get there? Same thing.

18. ### MrChips Moderator

Oct 2, 2009
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Why do they give time in hours, minutes and seconds?
Why not say "The time is now 7.12345 hours"?

Did you know that 60 minutes = 1 degree?

19. ### BillB3857 Senior Member

Feb 28, 2009
2,400
348
By his admission, he has had ZERO geometry classes therefore little or no understanding of angles would be expected. Until he gets the concept that units are broken down into subsets with different names, I think it a lost cause. I'll continue to follow, but I can't explain it in any way I haven't already tried. Maybe someone else can get through to him.

20. ### MrChips Moderator

Oct 2, 2009
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3,355
Did you know that one degree latitude is about 60 nautical miles?

Thus one minute latitude or one minute longitude at the equator is approximately one nautical mile.