Stupid Electricity Question aka self electrocution

[ruxtmp]

5 amps is more than would be required. A standard 9 volt battery should do the trick but make sure you use a parallel circuit. Also once you press the switch it will probably take 2-3 seconds before the engines will ignite.

 

[Brett327]

Am I the only one thinking that 5 amps (especially X3) is a helluva lot of juice to be screwing around with in the backyard?

Why not just shut off the breaker to your house, then splice an ignition wire in there. You should get about 200+ amps when you turn it back on. More is better, right? It's AC, though, so be careful. (I'm not serious, don't try this unless you just hate this cold, cruel world...)

Hillarious! I can see it now.

Come on, people, this isn't rocket science...uhhh, OK, I suppose that it is, but still. However you light these things off, those igniters are inprecise enough (timing wise) to make them almost impossible to synchronize. What I think you're going to need is an extra long rail on your launch pad to keep the thing traveling in the same direction until all the motors are running. Again, I'm sure people have done this kind of thing before, so do a little internet research and use what has worked for others.

Brett

 

[The Chief]

I cannot remember if they are going to be wired series or parallel... which ever one doesn't suck... I think. Uh, I'm pretty sure it's in series. ...

Danger Danger Eddie. You gotta know what you are doing. Either you learn it or have someone supervise you who does know.

The term "5 amps" is meaningless. It is like saying 5 feet. The qualifier is what is needed. Example: If you say you missed the drop zone by 5 feet, probably good. If you were 5 feet below the ramp when doing CQ's landings, probably not good.

To know what you are dealing with, you need to know the voltage, and or the resistance (impedance) of the circuit to calculate voltage. A 5 amp current draw at 1 volt produces 5 watts of power, at 10 volts you will get 50 watts. Some examples of voltaic cell output: 6 volt lantern battery, dead short across terminals produces about 8 amps, voltage drops due to internal resistance to about .3 volt, or about 2.4 watts, not very much power. Put them in parallel and you double the current, series you double to voltage.

Voltaic's used in laptop computers produce about 3 to 4 amps, 18 volts nominal, continuous duty. Some as high as 8 amps, but very expensive.

Car batteries are deadly. Short one and you risk explosion from the hyrdrogen being produced. The ring you are wearing and the right connection, ring becomes white hot molten metal, your finger and doctor are non-plused to say the least.

In summary, a rocket kit is one thing, but if you are building it yourself you need to better understand what you are doing and the consequences of what you are doing.

 

[Fly Navy]

Just a reminder, electrical current as low as 70 mA can kill a person. You need to do more research and even better, have someone to help you there who is knowledgeable.

 

[JIMC5499]

I just thought of something. You are using standard factory made rocket motors in this thing? Everybody has been trying to help you ignite this thing (my self included) and nobody even thought that you might be playing around with a couple of pounds of high explosives that you are calling rocket motors.

 

[Crowbar]

electrical current as low as 70 mA can kill a person.

My point exactly. That fatality threshold will sneak up on you fast if you aren't that well versed in electrical wiring and safety.

Ten Commandments of Electrical Safety

(1) Beware of the lightning that lurks in an undischarged capacitor lest it cause thee to be bounced upon thy backside in a most ungainly manner.

(2) Cause thou the switch that supplies large quantities of juice to be opened and thusly tagged, so thy days may be long on this earthly vale of tears.

(3) Prove to thyself that all circuits that radiateth and upon which thou worketh are grounded lest they lift thee to high-frequency potential and cause thee to radiate also.

(4) Take care thou useth the proper method when thou taketh the measure of high-voltage circuits so that thou doth not incinerate both thee and the meter, for verily though thou hast no account number and can be easily replaced, the meter doth have one and as a consequence bringeth much woe upon the supply department.

(5)Tarry thee not amongst those who engage in intentional shocks for they are surely non-believers and are not long for this world.

(6) Take care thou tampereth not with interlocks and safety devices, for this incureth the wrath of thy seniors and bringeth the fury of the safety officer down upon thy head and shoulders.

(7) Work thee not on energized equipment, for if thou doeth, thy mates will surely be buying lunch without thee and thy space at the table will be filled by another.

(8) Verily, verily I say unto thee, never service high-voltage equipment alone, for electric cooking is a slothful process, and thou might sizzle in thy own fat for hours on end before thy Maker sees fit to end thy misery and drag thee into His fold.

(9) Trifle thee not with radioactive tubes and substances lest thou commence to glow in the dark like a lightning bug.

(10) Commit thee to memory the works of the prophets, which are written in the instruction books, which giveth the straight info and which consoleth thee, and thou cannot make mistakes.

 

[Fly Navy]

I just thought of something. You are using standard factory made rocket motors in this thing? Everybody has been trying to help you ignite this thing (my self included) and nobody even thought that you might be playing around with a couple of pounds of high explosives that you are calling rocket motors.

Couple of POUNDS? Not even close. Have you ever played with model rockets? There isn't a lot of propellant... unless you're using D or E size engines, and even then, it's not a lot.

 

[Brett327]

Couple of POUNDS? Not even close. Have you ever played with model rockets? There isn't a lot of propellant... unless you're using D or E size engines, and even then, it's not a lot.

Yeah, nor are we talking about "high" explosives. Those Estes motors are really nothing more than gunpowder packed in a tube with a nozzle. The stuff just burns quickly - no detonation (important distinction).

Have we "nuked" this thing enough yet? :tongue2_1

Brett

 

[JIMC5499]

I asked at the beginning if he was using Estes motors. What I am concerned about is if he isn't using factory motors and is trying homemade ones. Anybody watch the Rocket Challenge show on TV. Those motors weigh several pounds and are homemade. I just thought that this guy might have seen one too many episodes of Mythbusters.

 

[nfo2b]

Have we "nuked" this thing enough yet? :tongue2_1

Brett

HAH! Not even close. A "real" nuke (MM, at least) would have first gone through 2 pages of calculations (all incorrectly), given himself a BOD (Power school grading terminology for "Benefit of the Doubt"), scratched his head, cut off the female end of a household extension cord, abandonded the extension cord in favor of a spare clothes dryer pigtail (b/c 240V is MUCH better than 120V, right?), used some speaker wire he had laying around in his garage to cover the distance from the end of said pigtail to the rocket in his backyard (which is set up 3 feet from a bale of oily rags), wired in a switch he scavenged off of his disassembled walkman, abandoned the switch idea because just touching the wire ends together is easier, abandoned the whole electronic ignition idea in favor of a butane grill lighter because, well, that's even easier...then he would tell his div-O that the burn marks and burnt eyebrows were the result of a Flaming Lambourghini gone terribly wrong...while telling his fellow MM's that they're the result of a homemade Napalm grenade he made out of Tide and gasoline.
That's how an MM(N) would "nuke" things out.
:banghead_
/threadjack

 

[Steve Wilkins]

That's how an MM(N) would "nuke" things out.

Now that's funny. Your average MM nuke types don't have a clue about electricity and don't want to know.

 

[The Chief]

... That's how an MM(N) would "nuke" things out. :banghead_

How could I double down rep points for this one?

Sounds like Eddie will make a good MM?

 

[eddie]

Wow.

Now that I stand back and look at this whole thing, it is very amusing, and I am glad I asked.

Yes, the rocket is home-made, but it is all Estes parts canibalized from other kits. Yes, it is balanced, for those who would doubt me even further (I'm sure I would make a better MM than an ET)...

JIMC5499 must be correct about the igniters needing only .5 amps, as 5 amps sounds like a lot, now that I've learned a few things.

Yes, the motors are standard Estes engines: C6-5s to be precise.

I believe this is series wiring: Clip Whips. There will be a switch between the battery and the clips.

Looks like I'll be going with the latern battery for now, and getting help. People do use car and motorcycle batteries for larger projects, but I clearly need to learn some more about all this.

Thanks.

 

[The Chief]

... I believe this is series wiring. ...

Uhh, No!

In a series circuit, failure of one component in the loop will cause the entire loop to fail, e.g., some christmas tree lighting strings, bulb goes out, all go out.

Parallel loop, failure of one component can/may/might affect the loop but in itself will not cause loop failure.

 

[eddie]

Uhh, No!

In a series circuit, failure of one component in the loop will call the entire loop to fail, e.g., some christmas tree lighting strings, bulb goes out, all go out.

Parallel loop, failure of one component can/may/might affect the loop but in itself will not cause loop failure.

Somebody (not on this board) gave me that same example before, but apparently got series and parallel mixed up. I guess this is how "bad gouge" spreads...