CS6PI

[kt315]

all same brand schematics that I see in forum seems industrial espionage microfilm shooted but anyway thanks Alexismex.

[Eugene51]

CS6PI

Alexismex , Thank-You for posting that !!! On this Forum , we never know who has the schematic we need ??? Like a deck of cards , who is hiding the last "ACE"...... I will add to my collection ....Take Care......Eugene51

[kt315]

Go to Eric Fosters PI web site and search on "CS6PI". You will find some additional information as Eric is the designer of this circuit for C Scope.

I have did share this not-mine photo of Goldscan-5. MOS-FET in DIP-4 also seems. I do not know Eric has opened new era in PI or, more probably. we are pepithecanthropes in these PI perspectives on the 'hight' ohms coil.

[Eugene51]

CS6PI

KT315 , Great Photo !!! I wish we can build that one , but I think it is still being manufactured ????........What is the model again of that P.I. photo ????......Again KT Thanks for posting..........Eugene51

[Jonas]

CS4PI

cs4pi

[Jonas]

cs4pi oscillograms

cs4pi working frequency 1.049 - 4.651 khz
Sample delay 30µs - 92µs pulse transmit to coil 50µs - 276µs peak amplitude about 90 volt

[gef12]

Go to Eric Fosters PI web site and search on "CS6PI". You will find some additional information as Eric is the designer of this circuit for C Scope.

I have did share this not-mine photo of Goldscan-5. MOS-FET in DIP-4 also seems. I do not know Eric has opened new era in PI or, more probably. we are pepithecanthropes in these PI perspectives on the 'hight' ohms coil.

So this is the Goldscan -5 ?????
nice n small , compact
would love the schematic of that
anyone ???
cheers

[amtech2005]

CS6PI

Goldscan 5 , I am pretty sure only 2 people have that Schematic . Eric and Mr. Bill !!
But , I sure would love "crystal-clear" digital photos of both sides of the PCB circuit board for personal use and testing only !!!!! amtech2005@yahoo.com I never ask for much Eugene

[amtech2005]

CS6PI

Jonas , thanks for posting the oscillograms of the TX pulse parameters from the CS4PI . So frequency is = to 1.049 to 4.651 khz the sample delay = 30-92 u.s. , which seems slow . and transmit pulse width = 50 to 276 u.s. . So you now have the Data to construct this machine without needing a pic-chip or the trouble to find the locked "software" . Because I believe you can build a pic-chip "Equivalent Circuit" , that will work just as Good , and without the pic-chip !!!!!!!! Just my opinion , any other comments please respond...........Thanks................Eugene

[kt315]

Jonas, to your acquaintance.
much usefull info on CS6PI and CS4PI you can find out in forum of Eric Foster and Mr. Bill Crabtree (hey people, who have asked me who is Mr. Bill?)
http://www.findmall.com/list.php?34
try Seach there. I see many oldie posts on this matter of guru's.

regards

Mr. Bill is advanced technician in MD technology who does these all updates for your detectors.

[Sean_Goddard]

A friend of mine bought one of these (CS4 PI) and found TWO gold rings first time out!! I was with him when he did it, and on a VERY difficult beach too.

I was using my Goldquest and found nothing as the conditions were just too bad (too many hot rocks).

[geroms]

Jonas,

The CS6PI, contrary to what the marketing literature says about it being a powerful PI detector, it is of the low power design. There is a resistor in series with a 10 ohm coil that has about 30 turns of AWG30 magnet wire. This coil will not operate much below about 15 micro seconds (us). The MOSFET is a 4-leg low power type that handles a peak flyback voltage of about 80V with a low peak coil current being about 100ma.

The frequency control adjusts the PPS rate, pulse width and delay. At the fastest PPS speed the TX pulse width is about 50us with a main delay of about 15us to 17us. C19 sets the frequency range and can be changed to a smaller value in the range of 680pf to 720pf (mica for stability) to approximately double the PPS frequency range (to about 13.5KPPS) and reduce the delay down to about 7.5us for small gold objects. At the max frequency with a delay of 7.5us the pulse width is about 22us. A 1000pf mica will put you in the 10KPPS range with the pulse width being approximately 30us with a 10us main delay.

A different low capacitance, fast, mono coil needs to be made to operate at this low delay range. I can detect a U.S. nickel to about 14" using this modification on the CS6PI with a 10.5" diameter coil, 300uH with 19 turns. Keep the new coil coax short to make a direct connection to the control box with about 30" to 32" of coax cable.

Change the first amp stage by adding a DIP socket and instert a NE5534A in the socket, tantalum caps on the +/- DC supply, enlarge the TX electrolytic caps to about 1000uf or what ever will physically fit.

Do not try to change the coil series resistor as the MOSFET will not handle much higher power. The series resistor along with the coil resistance, and MOSFET on-resistance makes the total TX circuit resistance of about 60 ohms to enable a faster turn on. The coil current rise TC is 5us (300 / 60). With a pulse width of 22us the coil current will reach about 97% of maximum current.

You will need a scope to investigate the operation of this PI machine before and after the modification. You will need to optimize the value of the damping resistor to match the new faster mono coil.

Go to Eric Fosters PI web site and search on "CS6PI". You will find some additional information as Eric is the designer of this circuit for C Scope.

bbsailor

Dear bbsailor

Is it possible to improve the CS4PI for small nuggets: reduce the delay, and an smaller coil ?
Could you help me?
Thierry

[bbsailor]

Dear bbsailor

Is it possible to improve the CS4PI for small nuggets: reduce the delay, and an smaller coil ?
Could you help me?
Thierry

Thierry,

Try to obtain a schematic of the CS4PI and compare it to the CS6PI and see if the main coil pulse is controlled by a 555 type chip that can have its timing easily modified by changing the value of the main timing capacitor or C19 in the CS6PI to a mica (low drift) type chip of about half the value to approximately double the TX frequency range. This will reduce the delay to about half or about 8.5uS. If the CS4PI TX frequency is microprocessor controlled, it is more complicated and I have no experience with this.

Eric Foster very cleverly designed the CS6PI machine to have the TX pulse width be 3 times the delay so that as the frequency control is increased, the delay is reduced but the battery power drain remains about the same. More importantly, the output MOSFET is a low COSS type and will not tolerate high current going through the coil. The stock CS6PI has about a 17uS minimum delay with about a 50 uS pulse width. The stock CS6PI 10 inch coil uses 30 turns of AWG 30 with about 1000uh of inductance. To operate the CS6PI coil at a lower delay, the coil needs be rebuilt with about 19 turns to about 300uH. See my fast coil article in the projects section of this forum. This fast coil article should apply to a modified CS4PI operating at a modified lower delay.

Smaller coils always work better for smaller targets. Small nuggets have a lower time constant and require earlier sampling to detect them. However, fast coils bequire less internal capacitance between coil turns and less capacitance between the shield and the coil as well as less capacitance in the coax wire connecting the coil to the PI circuit board.

I hope this helps?

bbsailor

[geroms]

bbsailor,
Thank you for your answer, and just make a post to find scheme and the principle of operation of the coil Oscilator.
On SC4PI there are 3 components that resemble a 555
1 - NE55534AP
2 - TL062CN
1 - IRFD110 (4 pins)

1 / I made a coil with wire 0.4/0.5 mm, diameter 156 mm, 51 rounds, the resistor is only 5.6 ohms, against 15.6 on the original disk.
The detector reacts much better on small nuggets with very little loss on target averages.
Is that a problem to use this disk because of its low impedance?

2 / The detector responds well to small nuggets with potentiometer frequency background to 4200 PPS
Is it possible to inprove a little this setting?

3 / The best Audible threshold setting is only half, if increasing it there is false sounds.
Is it possible to filter to reduce noise and increase slightly the sensitivity of the sensor?

[geroms]

Hi
It is possible to replace the 4 Mz quartz who manages the frequency with a 6Mz quartz, the scan rate increases, and I guess the delay decreases.
In the air the results are very positive, the detector take small nuggets. But outdoors, there is a problem with the ground effects. Did you have had this problem after increasing the frequency on the cs6pi, how to solve?
There are two variable resistors vr1 and vr3 on CS4PI but I do not know what they do they and if they regulate the ground effect?