Jump to content
Nugget Shooter Forums

Detector Coil size VRS. Battery Draw P.I. Detectors


Recommended Posts

I am looking for an answer from someone with an electronics background on this.

The physical size of a coil lets take for instance an 11 inch round and compare it with a 16" round.

My question is will the larger size coil deplete the battery faster vrs. a smaller size when in use on a P.I. detector ??

My guess is that it will but I am not sure about this.

Link to comment
Share on other sites

Frank,really can't answer your question, but have a solution. You've been running that 16" for quite awhile and know about how long the battery lasts. Now this season, run a 6" round only for the whole season and compare. ;-)

Just buy a new battery-

Shep

Link to comment
Share on other sites

Well Billygoat, I don't quite understand what you are saying, when you state RF does this mean radio frequency ??

And DC pertaining to direct current ??

Is your statement from electronics knowledge ??

I need someone to reply here that understands the actual operation of the system that can definitely state an answer.

When using a 16 18 20 inch coil versus the smaller coils 11 round or 9x14 elliptical etc. this is what I am trying to figure out.

Does the detector consume juice (power) quicker from a fixed source like the DC battery systems we use on the Minelabs.????

Link to comment
Share on other sites

Shep its not a matter of needing a new battery. I have 3 new batterys Lipolys .

I am trying to understand this better and find out about power consumption.

Other variables like an inline amp I assume will drain some power from the batt also.

And then there the headphones and external speakers to consider they all take power to operate.

Maybe Reg or someone here will chime in that has a formal electronics background.

Link to comment
Share on other sites

I am looking for an answer from someone with an electronics background on this.

The physical size of a coil lets take for instance an 11 inch round and compare it with a 16" round.

My question is will the larger size coil deplete the battery faster vrs. a smaller size when in use on a P.I. detector ??

My guess is that it will but I am not sure about this.

........Hey Frank, if onyone on here is qualified to answer yer question it'd be "Homefire". If I'm not mistaken, he's the closest thing to bein an electro-mechanical engineer on here. Geez, if he can build an "Earth Resistivity metre w/"C"probes, from scrach and scrap parts, he ought to be able to answer yer Q. Send him a PM. (kinda suprised he ain't chimed in on this already)
Link to comment
Share on other sites

Gottcha Billygoat, I basically understand that.

Which is why I am questioning this matter.

We have "resistance" in the lengths and types of wire which is being fed DC current in any application. Thats one of the principals I am taking into consideration pertaining to my question.

So yes I can imagine a small coil VRS. larger coil would be the same power usage if they both had the same amounts of the same type wire.

Link to comment
Share on other sites

FRANK, I DON'T THINK THAT THE SIZE OF THE COIL MAKES MUCH DIFERENCE IN BARRERY DRAIN. EACH TIME YOU PASS THE COIL OVER A TARGET THE RESPONCE USES POWER FROM THE BATTERY. WITH A SMALLER COIL YOU CAN PINPOINT THE TARGET MORE QUICKLEY THAN WITH A LARGER COIL.

THE LESS THAT YOU PASS THE COIL OVER A KNOWN TARGET THE LOWER THE BATTERY WILL DRAIN.

I HOPE THIS HELPS.

HARRY

Link to comment
Share on other sites

Hi Frank,

I am using LIPO batt 5200mah. From my experience while using 16 " NF coil , the batt can last till 2 -3pm.

While using smaller coil ( 8" or 6x8" coil ), the batt will last all day. ( with some small remaining )

And no , I have no electronics background . :cry2: but economics background. :arrowheadsmiley:

Link to comment
Share on other sites

The only difference I can see, is if one coil impedence matches the other coil impedence better than the other. That's the difference I see. Less sensitivity, and can't go as deep.

Very, Very little significant difference on draining a battery quicker over target tones.

Link to comment
Share on other sites

FRANK, I DON'T THINK THAT THE SIZE OF THE COIL MAKES MUCH DIFERENCE IN BARRERY DRAIN. EACH TIME YOU PASS THE COIL OVER A TARGET THE RESPONCE USES POWER FROM THE BATTERY. WITH A SMALLER COIL YOU CAN PINPOINT THE TARGET MORE QUICKLEY THAN WITH A LARGER COIL.

THE LESS THAT YOU PASS THE COIL OVER A KNOWN TARGET THE LOWER THE BATTERY WILL DRAIN.

I HOPE THIS HELPS.

HARRY

If that's the case Harry a fully charged battery will last me a life time.... :cry2:

Link to comment
Share on other sites

If that's the case Harry a fully charged battery will last me a life time.... :cry2:

LAST YEAR I NEVER RAN MY BATTERY DOWN. THIS YEAR I'M GOING TO TURN MY DETECTOR ON .

HARRY

Link to comment
Share on other sites

Large and sniper type coils are set to the same Inductance and DC Resistance.

There should be NO difference in batter current being used.

The Larger coils just spread the Field over a larger area . Yes they should go deeper but because of the Weaker field they will not detect the smaller target like the smaller coil will.

Link to comment
Share on other sites

O.K HOMEFIRE SO PERTAINING TO WHAT YOU ARE STATING NO DIFFERENCE IN BATTERY DRAIN FOR EITHER LARGE OR SMALLER COILS.

I GUESS I HAVE TO START LOOKING AT AMPLIFIERS AND HEADPHONE CIRCUITRY TO CHANGE OR EXTEND BATT LIFE FROM EACH CHARGE.

I ALSO UNDERSTAND THE MORE TARGET SIGNALS ENCOUNTERED ARE DIRECTLY RELATED TO BATTERY CONSUMPTION WHEN RUNNING AN AMP BECAUSE AN AUDIO SOUND MUST BE PRODUCED FOR EACH AND OF COURSE LARGE SIGNALS OR ( OVERLOAD TYPE) SIGNALS MUST CONSUME EVEN MORE JUICE TO PRODUCE THE TREMENDOUS SOUND.

HOMEFIRE DO YOU HAVE ANY GUESTAMATE OR IDEA OF HOW MUCH JUICE IS CONSUMED USING THESE TYPES OF AMPS WE USE ON THE P.I.'s ????

i AM GOING TO EXPERIMENT WITHOUT MY AMP ON THE NEXT OUTING AND JUDGE THE AMOUNT OF TIME MY BATTERIES CAN HANDLE.

ALSO A QUESTION ON NEVADA CHRIS's STATEMENT ABOUT THE MOTHERSHIP WHICH IS A REALLY BIG COIL AND HE STATES THE BATTERY CHARGE DOESN'T LAST VERY LONG.???

HOW WOULD YOU RELATE OR EXPLAIN THIS SITUATION ???

THANKS FOR CHIMING IN.

Link to comment
Share on other sites

In order for the coil to perform as the machine is built, it would have to be matched as the same DC Current Drain ( R ) and Impedance.

Other wise your throwing off the Input.

You would have to adjust your Damping resistor to optimize the machine. That is a Warranty Buster.

If your having Battery issues it must have something to do with the Bells and Whistles and Condiments you have on your battery use.

Any add on Boom Boks Amp, or what not should tell you what the Current Requirement is.

Just add it up.

A LM386 based amp in the high gain mode should only use say a quarter amp or so.

http://www.ti.com/lit/ds/symlink/lm386.pdf

Link to comment
Share on other sites

I think this link will provide some insight.

Sometimes a small dim light bulb goes of in my head and I remember useless stuff. I say useless because the discussion is purely academic and has no bearing on "in the field" usage, other than changing batteries a few hours sooner.

http://www.arizonagoldprospectors.com/invision/index.php?/topic/77860-coil-sizes-and-battery-life/

Link to comment
Share on other sites

Yes thank you both and NVCHRIS THANKS for the link to that ol post Reg had going I learned a BIG BUNCH with it.

Now I'm ready to do some real time experiments on both battery life and detection capability

Thanks All

Link to comment
Share on other sites

Frank my gp2000gpm runs on a 12v battery. My voltage is adjustable from 8.8v down. If I use a 6" coil I can't go over 7v or the detector shuts down. With larger coils I can run at 8.8v this tells me the detector can put out more juice to the larger coils. But the 6 " coil is too small to transmitt the extra voltage. Thus my unit uses less battery power with a smaller coil. If the coil is only a antenna why do I get more depth with extra voltage to the detector?

Link to comment
Share on other sites

Gottcha Sgt.

As far as applying the x=tra voltage and gaining some depth I believe there is a small range where a bit of added voltage increases the capability of depth penetration and holding a steadier threshold then beyond that slight range of added voltage / advantage, it crosses over into another range of ill performance and possible damage to components from what I have read on the subject.

Link to comment
Share on other sites

A detector coil is not being used as a antenna in the radio sense. More like a Pick Up Coil.

Current passing through a coil generates a Magnetic Field. EMF.

More Current the stronger the Field.

Higher Voltage = More Current being pumped into the coil.

Batteries are rated in Voltage and Current Available over a given time.

The more Current consumed the less time they will last and the Voltage drops.

Without going into Inductance Theory , that's the easy way to say things.

Sounds like one of your coils is able to Sink (USE) more current then the other.

I suspect the detector is seeing this as a short and is shutting down in protection mode.

Link to comment
Share on other sites

Had a long post to speak to SGTFrank's experience, but my phone hosed up.

SD does not have input regulator and IJ regulates at max safe voltage.

If memory serves ne there is a sort of current output/receive matching setup on the coil side of older models that acted as the 'regulator'. Since your input voltage is already taxing the coil output, the soak of the smaller coil is likely what is causing such a strong feedback and forcing you to turn down the current.

Homefire can better explain. I don't want to lose another post.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...