Robot Arm C

[chess884]

So I have a rather nice piece of equipment rated for 24V that I would love to use. Unfortunately the voltage limit on the event is 14.4V, it functions acceptably at 14.4V on a power source, but really really well when using the rated voltage (duh). It was pointed out to me that I could just use a DC to DC converter to raise the voltage to the motor without sacrificing current. To clarify the DC to DC converter does not quite function like a transformer where I*V = I2*V2. The converter draws more current at the battery to output more voltage (the power input and output are the same with 100% efficiency). Please correct me if I am wrong on any of this.

My question is: Is it legal / does it violate the spirit of the rules to use a DC to DC converter to use a voltage above the 14.4V limit at the same current?

[windu34]

So I have a rather nice piece of equipment rated for 24V that I would love to use. Unfortunately the voltage limit on the event is 14.4V, it functions acceptably at 14.4V on a power source, but really really well when using the rated voltage (duh). It was pointed out to me that I could just use a DC to DC converter to raise the voltage to the motor without sacrificing current. To clarify the DC to DC converter does not quite function like a transformer where I*V = I2*V2. The converter draws more current at the battery to output more voltage (the power input and output are the same with 100% efficiency). Please correct me if I am wrong on any of this.

My question is: Is it legal / does it violate the spirit of the rules to use a DC to DC converter to use a voltage above the 14.4V limit at the same current?

Keep in mind that any statements made here are not official clarifications. That said, after reading over the section of the rules in question, the wording makes it pretty clear that as long as the voltage stated on the batteries is less than 14.4, DC-DC converters are allowed and do not violate the spirit of competition, however I urge you to submit an official clarification on sonic.org.

[jander14indoor]

Also, not official, this is just a discussion forum, not an outlet for rules clarifications, etc...

Quoting from the rules: ...as long as the expected voltage output across any points does not exceed 14.4 volts...
I know it then goes on to state it will be determined by checking battery rated voltage.

This is where using 'intent' may get you. The purpose of limiting voltage is safety. Using labeled batteries to do this is to keep judging easy and avoid having ES of unknown skills probing circuits with a meter and possibly causing damage. A converter like you mention seems to me like a way to get around the 'intent' of the rules.

Now I'm one who vehemently objects to using 'intent' when interpreting rules whenever possible. I do so because from experience I know the rules writers when talking often can't agree on the 'intent' they have while writing the rules, let alone what the intent was weeks or months later. Gets even worse when someone who didn't write the rules tries to determine the 'intent' of the original writers.

BUT, this is a safety question, and convincing an ES or appeals committee they are wrong on a safety question is VERY difficult.

All that said, I suspect that using a DC-DC converter is at least pushing the intent of the rule (safety) if not the letter.

So, what do you do.
- I'd suggest you at least ask a rule clarification when they open. Depending on the response you may find you are OK, or get a clear message you aren't. As this is a safety question, you might want to be clear on why there is no more risk with your proposal than would otherwise exist.
- You could just drop the idea, that at least would be safe from a competition point of view, and find another way to get adequate performance.
- Go ahead without a clarification and risk being second tiered at competitions and hope to be able to win an appeal.

Good Luck,

Jeff Anderson
Livonia, MI

[windu34]

This topic brings up a similar topic from the 2008-2009 rules for electric vehicle where teams were using dc-dc converters because of the low allowed battery voltage of the allowed battery pack. It was deemed perfectly legal and in the spirit of comp. so it is likely that it will be allowed in this event as well.
I would of course submit the official clarification and let us know what they decide.

[windu34]

I was checking the math for the points possible and it added up to 113 and not 103. Can anyone verify this?

[chess884]

(6+6+5+5+5)
Two ping pong balls in the East goal in the marked spots, Other three ping pong balls in the remaining marked spots in North and West goals.
+ (5*4)
Five pencils in the West goal
+ (5*4)
Five legos in the North goal
+ (6*4)
Four dice in the North zone with an even number facing up
+ 4+5+5+5
One point for each of the 19 items in the North Zone

I get a total of 110?

[bearasauras]

There should be a rules clarification on this soon. Thanks for pointing this out.

[bearasauras]

And our first clarification is posted on the https://www.soinc.org/official_rules_clarif.

7.f: should read "The maximum number of points possible is 110."

[JimY]

Can anyone point to me where to find the allowed frequencies in soinc.org? The key question is whether the ranges are the same as in the past or not.

[windu34]

Can anyone point to me where to find the allowed frequencies in soinc.org? The key question is whether the ranges are the same as in the past or not.

I believe the rules state 2.4Ghz