Latest Minelab Patent - 11th Feb 2016

[daverave]

i wonder if the fisher CZ range is a type of discriminating pulse cause i think my friend once said that the CZ6 transmitted a square wave and the depth was very close to the earlier pulse machines.

[moodz]

There are couple ideas around - I forgot patentee (not under those exact term, so I wrote "recuperation").

On widely available 8x1.5V AA alkaline batteries, Fisher Impulse work easy more than 100 hours.
For some nowadays PI, even 10 hours and using heavy lead acid accu appear to be dream score.

SPECIFICATIONS 1Length 2 ......... Extended .................................................. .................... 50" Collapsed .................................................. .................... 31"Weight 2 ........ Complete (with Headset) .................. 5.2 lbs. 5.5 lbs.Handle and Search Coil...................... 2.3 lbs. 2.6 lbs.Control Housing ..................................... 2.4 lbs. 2.4 lbs.Transmit Frequency ........................................ 5,333 pulses per second crystal controlledAudio Target Response (Headset) ................................................VC O 3Visual Target Response.......................................... ........................1. LED 4 2. LCD bar graph 5Headset .................................................. ....... Waterproof, Piezo ElectricInterchangeable .................................................. ........ NoGround Balance Required .................................................. ............... NoSearch Motion Required .................................................. ................... NoDetachable Control Housing for Hipmounting................................YesSalt Water/Fresh Water Operation......................................... ...........YesLand Operation .................................................. ..................................YesSubmersible.. .................................................. .......................... to 250 feetSearch Coil Type .............Dual Spider coil, (Non-inductive balance) Diameter.................................... 8" or 10 1/2" Shielding ........................................ 100% ESI 6 Interchangeable .................................... NoBatteries .................................................. ............ (1.5-Volt, AA penlightBattery Life 2 ............. Carbon Zinc ....................................... 40-50 hours Alkaline .............................................. 100+ hours Nicads ............................................... 20-25 hoursAutomatic Battery Check .................................................. .................YesOperating Temperature....................................... ...................... 32-120°F

That is very good ... and the PRF is 5.333 Khz .... amazing. Any idea of the coil inductance or average depth ?

Answered myself .... one review seems OK here ...https://www.losttreasure.com/Home/FieldTestDetail/6124

[Teleno]

There are couple ideas around - I forgot patentee (not under those exact term, so I wrote "recuperation").

On widely available 8x1.5V AA alkaline batteries, Fisher Impulse work easy more than 100 hours.
For some nowadays PI, even 10 hours and using heavy lead acid accu appear to be dream score.

Most PI's strive for a fast flyback for detecting short time constants. This costs energy and is mostly wasted anyway because most of PI's have sampling delays above 15us.

Instead, Fisher Impulse allows the coil to be discharged through diodes into the power supply's capacitors. This causes a slow flyback but it conserves energy. Targets with tau longer than 15-20us are just as detectable as they are with conventional PI's. I bet Fisher Impulse fails miserably at smaller taus though (confirmation requested), but then again that's not its purpose.

[WM6]

i wonder if the fisher CZ range is a type of discriminating pulse cause i think my friend once said that the CZ6 transmitted a square wave and the depth was very close to the earlier pulse machines.

If so, then purpose of square wave is probably to get better harmonic spectrum, to work with n-th harmonic. Despite of that, it still remain in field of VLF/IB technology. Known solution with some Minelab CW patents and detectors too.

[Dave J.]

The CZ operates in the frequency domain, not time domain like PI's. It's a type of induction balance VLF technology, operating at 2 frequencies simultaneously. Introduced in 1991 and still in production virtually unchanged.

The Fisher Impulse (no longer in production) was fully static (i.e. not "motion" or "autotune") and air tested on US coins out to about 10-12 inches (25-30 cm) as I recall. Sensitivity to low conductors was high enough that it did "see" salt water more than just a little bit, but of course a lot less than a regular VLF. No use for gold prospecting since it wasn't ground balanced. Like all PI's, it was rather vulnerable to electrical interference. Didn't like power lines at all. And in Los Banos we were able to detect some kind of U.S. Navy VLF transmitter somewhere up in the Suisin Bay area well over 100 miles (160 km) away (we RDF'ed it by triangulating from Santa Cruz) but holding the searchcoil plane horizontal nulled the H-field so it wasn't really a problem.

[kt315]

Like all PI's,
---
Fisher Impulse is not PI. it has halfbridge TX driver like you can see it in CZ5/6. if fisher impulse is PI then CZ5, MXT, DFX,
Elite::GT, Explorer, Vision v3, etc are too PI, but they all are not PI.

[Dave J.]

kt315, the Impulse is pulse induction. The CZ is IB VLF technology.
I know what they are. I designed them and my name is on the patent which describes both technologies. The Impulse circuit is posted in the schematics forum, and I think the CZ circuit is as well.

I also designed the circuit (but not the software) for the White's DFX and Surfmaster. Also IB VLF technology. And, the MXT (circuit and software) which is sinusoidal single-frequency.

The Minelab multifrequency technology that began with the Sovereign is not pulse induction, it is induction balance sequential multiple frequency.

[kt315]

ok. let me look on tx o-scope pics from the fisher on a coil i could REALLY see what you mean. if there is the "delta pulse" - you win.

anotherway - satisfaction.

[kt315]

pulse induction signal

I reminder WHAT is THE pulse signal.

[kt315]

The Minelab multifrequency technology that began with the Sovereign is not pulse induction

this is FULL-bridge TX driver of Sovereign XS. in your logic it is not PI, but HALF-bridge driver in firsher impulse is PI.
nonsense, Dave....

[kt315]

And, the MXT (circuit and software) which is sinusoidal single-frequency.

un-sinusoidal. driver is working in impulse mode, a coil is un-resonanced. if you insist that is not let me see your schematic.

[WM6]

KT315, what you post, is only one of very classical PI design presentation.
Signal shape on TX coil could not be only decisive, if some MD design suit to PI or CW.
Decisive is how signal is processed in MD Circuits.
If we have Time Controlled Receiver (Time Domain), then we are talking about PI technology.
Does Fisher Impulse has Time Controlled Receiver? From my point of view (apart from that I 100% believe in inventor), yes.

[kt315]

This is only one of very classical PI design presentation.
Signal shape on TX coil could not be only decisive, if some MD design suit to PI or CW.
Decisive is how signal is processed in MD Circuits.
If we have Time Controlled Receiver (Time Domain), then we are talking about PI technology.
Does Fisher Impulse has Time Controlled Receiver? From my point of view (apart from that I 100% believe in inventor), yes.

in your logic any VLF is PI just cause has the TCR )))

[kt315]

pi transmit page 143

[Dave J.]

And, the MXT (circuit and software) which is sinusoidal single-frequency.

un-sinusoidal. driver is working in impulse mode, a coil is un-resonanced. if you insist that is not let me see your schematic.

Nearly all single-frequency metal detectors are sinusoidal. If you don't know what the MXT is, I know with absolute certainty it's sinusoidal because I designed the thing and it's still being manufactured that way, so why are you arguing with me about it? I usually expect smarter behavior on this forum.

The Minelab circuit and waveforms and patents have been around for more than 20 years. The "BBS" etc. technology is not PI. It is sequential multifrequency. Has nothing to do with half-bridge or full bridge, I've done both PI's and VLF's both ways, there's a full bridge switching nonresonant VLF sitting on my desk right now. I've been doing this stuff for a living for 35 years with successful products under a whole slew of different trademarks, it's not like I'm clueless.

If you don't want to believe me about anything, there are other folks here who also know their stuff, you can learn from them.