Noiseless power supply for SD2200V2?

[BillNEWAST]

I have hunted this site for a Schema for the powersupply and only found the ones for the sd2000 and the sd2100.

Is the Schema for the SD2200V2 is the Same as the sd20/sd21 and if not what are the differences?

Is the Schema for the SD2200D the Same as the SD2200V2 and if not what are the differennces?

What is the max Vin for the SD2200V2, Woody says the mosfet can be changed to a more robust one and the Vin can reach 8-9Vdc, with some other componet changes.

What I would like to do is be able to replace the WHOLE powersupply frontend with a Bucking Inverter IC that uses a 9-12V maybe 18Vdc(the new Lithiumn 18V Batts for power equiptment drills and such).

The CCT would have to take a Vin of these voltages and stepdown the Vout to the Transmiting currents needed.

When the Pulse Stops the Power would shut off thereby eliminating and emi/transiets to the Receive CCT.

I don't know what the Vout to the Transmit CCT is nor the Current needed and/or maxed.

What is the Freqency of the transmit cct?

What is the Timing of the Tx/pause/RX cycle.

What would be needed is a IC that could sens when the TX stops and Shut down the V/I out till it was needed again.

This would ALSO Save on BATT usage as the %Duty Cycle in Off and On modes.

Any Help Thoughts or What Have You will be greatlly apreciated.

Sincerely
Bill Adams

[Mechanic]

G'day Bill,

Well I don't think that there are any off the shelf power supplies that are designed to suite the specific needs you are after. There are however ones that you can send a sync pulse to, but it will not sync to the tx like you want it to. Candy makes discrete power supplies for his detectors(as in he does not use an off the shelf switchmode controller). There are no publicly available schematics for the 2200 so if you did want to modify it you would have to reverse engineer it first, without letting the smoke out!

What I would suggest is to just try and identify the electrolytic caps for the power supplys(there will be 2) and replace them with new low esr caps of the same value and also install some low esr tantallums(about 10uf) underneath them in parallel with the original cap. Also replace the other electrolytic caps on the board as well(tx tank, snubber etc) Do not worry about the filter caps they are polypropylene not electro's. Also be very careful when removing caps from the ml boards, they tend to like lifting the through hole pads off the board. 2 people are good for removing them, 1 to hold a hot air gun to keep things warm, the other on the soldering iron adding fresh solder to both pins and gently pulling on the cap.

As far as replacing the input power fet goes with a more robust one, this is probably a good idea, but I don't know how high V you really want to go, a little more than standard would be fine, but if you were to go too high, you would most likely find that the ground gets noisier and the detector unstable. If you go a little more than too high, you will let the smoke out of a mystery part!

Cheers Mick

[BillNEWAST]

Mechanic, Thank You for your input and warnings.

In regards to the "Input Power Fet", the max Vdc would be 9vdc from possibly an old Mikita Drill Batt.
I currently run a 7.8 Cannon Lithium cammera batt. I just heard that if the fet was replaced then you could use 8+ Vdc and the rest of the CCT would handle the Added V/I???

And Again What is the Difference between the SD2200D and the SD2200V2???

I also need to know if anyone knows if the Powersupply on the Board for the SD2100 is Different to the one on the SD2200V2?

It would be nice for all the Modders who have back engineered the different models could combine their Knowledge and Experience to Define Differences/UPGrades ML did on the SDxx00 series of detectors and have a Common List of Specs for Each of these Models. I know I'm asking a lot of them but I don't have the EET Background to do this. All I can do is go off of others who are more knowledgle than I. My knowledge is based on 25 year old Electronics course I took at a 1 yr collage.

Have a nice day and thanks to anyone who can help!
Sincerely
Bill Adams

[Mechanic]

G'day Bill,

It would be nice for them to share this info, but very unlikely IMHO.

Without knowing the exact specs of the ic's I would be very careful applying extra voltage to your detector. Woody said that the maximum he had run one at was 8v, which should be fine. I can run my 2000 up to 8.5v, but the ground becomes too noisy and I find very little gain in target response anyway. I think I figured out that the absolute maximum voltage I could theoretically apply was 10v(I have never tried this) as the tlc271 maximum voltage is 16v (battery voltage(10v) + 5v= 15v). Also the tank caps would need to be higher voltage as they are only rated to 10v and you are meant to use caps 2X the normal working voltage, but I think 1.5X would be sufficient. When you start raising the voltage rating of the cap, the esr starts to get higher, so a lower voltage lower esr cap could potentially deliver more current anyway.

Is your detector noisy? Might be a good idea to just replace the fet and leave well enough alone, or even better still leave the fet in until it turns black one day.

As for the differences between the different sd models, the main one would be different timings.

Cheers Mick

[Rov]

Hi Mechanic,an aside to the topic.I have arrived an.ML sd2000 detector box,on my workbench. it has been heavy modify past 10 years from several other?
The pcb x2 has been stripped? comformal coatings. and the Stefan VCO and Ismeal mods stripped to standard sd 2000.Not by me,but it has been Binned!
This unit still fire up with a standard 11inch coil but detect nothing!
Is this worth resurect? and by Who? Aust. Woody,May or may not engage in these resurection? any tips or direction? Thanks Regards Rov.

[Rov]

Hi Pm. if off topic to the subject,which probably is!Thanks Mate!
Rov

[BillNEWAST]

Mechanic, I do not want to run the SDxx AT the Higher Voltages, only to be able to use a Larger Vdc so you don't have to run into the Low Voltage Fade out at the end of a
10-12hr day.

It's my understanding from what I've read that the optiumn Voltage for the SDxx's is 7.4-7.8Vdc. Most of the Light Lithium Camcorder Batt's are about 7.5-8. So my reasoning is that when the bat gets to <=7.4Vdc you start to loose Sensitivity and Depth. I would just like to be able to use a higher Source and Buck it down to 7.8Vdc and have it last 10-12 hours and not drop below 8Vdc at the source. Then you wouldn't drop below the miniumn Vdc needed to run at the optiumn of 7.8Vdc Also it would be nice to have two Camcorder Bat in series >=14Vdc then you wouldn't have to change anything. Just Buck it down to 7.8Vdc. I know that this could be done on a external bat pack and just feed the SDxx with a constant source. If anyone is interested the Bat Pack could be made with the heat formable Fiberglass?? stuff used for making Knife and Gun Sheaths.

STILL HOPING FOR A GIFT FROM THE GURU'S ON THE SPEC'S AND SCHEMATICS for the SD2200V2.

[Mechanic]

G'day Bill,

I see what you want to do now!
What you really want is to build a regulator to drop the voltage from 14v to 7.4~8v. An adjustable one would be ideal and the simplest method. The detector will draw about 900ma, so you will need one rated to at least 1.5A, but 3A would be better. They normally dissipate a bit of heat so you will need to consider that when building it.

There are plenty of adjustable ldo regulators out there
Link

You can also get kits from the likes of JayCar(in Australia) and any decent hobby electronics stores should stock them.

The reason I have suggested the ldo regulator is because it will be a simple design,and does not need to be synchronized. Switching regulators are much more efficient, however the design will become much more complex and yes you would need to synchronize to a clock source within the detector. A poorly designed/laid out switching regulator will cause noise and can be more trouble than it is worth.

Cheers Mick

[mario]

The drop from 16v (fully 14.8V charged lipos are more like 16V!) to 7.xv is huge.

Don't expect the regulator to operate cool or quiet for extended lengths of time.

I was running my detector at 7.4V from a 11.1V lipo pack using a switching regulator for several months before the thing blew. I was lucky to include surge protection into the circuit, otherwise my detector would not be operational.

Also, the detector runs much more quiet using straight battery power, so expect it to be a little more noisy as well.

[BillNEWAST]

Thanks Mick, the Switching Regulator Noise is Exactly what I was talking about trying to get rid of by shutting down the TX side of the source to eliminate it.

Maybe I'm not asking the right quetions. I hope the below is the Quote from Woody on his forum, that got me started on this whole Path, Hope you don't mind Woody.

"A bit of extra performance can be obtained from the SD series detectors by feeding them with a voltage up to 7.6 volts. But doing this comes at the risk of blowing the small Mosfet that generates the supply voltage for part of the circuit. The component is worth about $1 but it is a pain to pull the detector apart and replace it. The part in question is a variant of a 2N7000 type device and these components are only rated for suppyling 100 ma of current. When the input voltage is raised this component becomes stressed and can pop when the detector is turned on. The fix is to install a more modern beefy Mosfet, the only trouble is that the driving circuit does not switch hard enough to drive some of the common Mosfets. There are some new devices that will be a good replacement, the one i think is the best is the lRLML0060TRPBF. This device can pulse up to 2.8 amps and is rated for low gate charge. I have done this upgrade to a SD2200D and can now run it on 8 volts. The switchmode components stays cool to the touch.
If we want to make a really nice detector we can do the following. Remove the plus and minus 5 volt supply components and install a dual regulated separate power supply module that has provision to sync lock to the transmitter. This will remove the switchmode noise from the reciever and lower the noise floor.."
and thatnks Mick for the Amps in Reference of 900ma and the max for the part of 3A.

I guess if I just keep hammering away I'll be able to get a Set of Specs with parts and Schemas for my SD2200V2.

Sincerely
Bill Adams

[bklein]

."A bit of extra performance can be obtained from the SD series detectors by feeding them with a voltage up to 7.6 volts. But doing this comes at the risk of blowing the small Mosfet that generates the supply voltage for part of the circuit. The component is worth about $1 but it is a pain to pull the detector apart and replace it. The part in question is a variant of a 2N7000 type device and these components are only rated for suppyling 100 ma of current. When the input voltage is raised this component becomes stressed and can pop when the detector is turned on. The fix is to install a more modern beefy Mosfet, the only trouble is that the driving circuit does not switch hard enough to drive some of the common Mosfets. There are some new devices that will be a good replacement, the one i think is the best is the lRLML0060TRPBF. This device can pulse up to 2.8 amps and is rated for low gate charge. I have done this upgrade to a SD2200D and can now run it on 8 volts. The switchmode components stays cool to the touch.

Please check my GP Extreme Badness thread in the Tech forum. I wonder if my detector has the same issue as described here. The previous owner used a Pocket Rocket battery supply which has a switch for 6.7V for the Extreme or 7.3V for SD2000. So maybe he switched it the wrong way and "let the smoke out"? The IRMLxxx number doesn't seem to be a good one. If you have any suggestions on my repair please add to that thread... Thanks.

[mario]

Please check my GP Extreme Badness thread in the Tech forum. I wonder if my detector has the same issue as described here. The previous owner used a Pocket Rocket battery supply which has a switch for 6.7V for the Extreme or 7.3V for SD2000. So maybe he switched it the wrong way and "let the smoke out"? The IRMLxxx number doesn't seem to be a good one. If you have any suggestions on my repair please add to that thread... Thanks.

This detector, though deprecated, is too recent. You are going to have a difficult time finding any help repairing it. Of course you can send it out and have some one repair it, but you are likely to pay what a working unit would cost you.

The best advice I could give you is to remove all that white gunk, some of us here would not mind helping you identify those components, but we are going to need your help.

[BillNEWAST]

bklien, This is the link to the IR N channel Mosfet.

https://ec.irf.com/v6/en/US/adirect/ir?cmd=catSearchFrame&domSendTo=byID&domProductQue ryName=irlml0060trpbf

Guess no one is willing to share on the Original Posts Questions.
If we could pool all the knowledge that is Compartmentalized in different folks experience there would be a schematic and SPECS for these different machines, that could be in ONE Place, not scattered over 3000+ posts and 50 threads.

Just some Basic Info like What is the asked in the original post. This would allow people like bklien, or anyone know what is needed to START the troubleshooting process, and then be able to make an informed decision as to their skill leval as to whether to Attempt the Repair and/or to have it sent off to a Technition for repair. They would be able to make the Cost Value Experience decision.

I originally started this Thread as a SD2200D -+ V2 so folks could have a Single Point of Reference for these machines, NOT the Previous ones or the ones after. This was so anyone could come here and share and get info on. When that reached a point to be able to draw up a schematic, then it could be posted for all to use to repair their machines.

OH Well!

Sincerely
Bill Adams

[mario]

bklien, This is the link to the IR N channel Mosfet.

https://ec.irf.com/v6/en/US/adirect/ir?cmd=catSearchFrame&domSendTo=byID&domProductQue ryName=irlml0060trpbf

Guess no one is willing to share on the Original Posts Questions.
If we could pool all the knowledge that is Compartmentalized in different folks experience there would be a schematic and SPECS for these different machines, that could be in ONE Place, not scattered over 3000+ posts and 50 threads.

Just some Basic Info like What is the asked in the original post. This would allow people like bklien, or anyone know what is needed to START the troubleshooting process, and then be able to make an informed decision as to their skill leval as to whether to Attempt the Repair and/or to have it sent off to a Technition for repair. They would be able to make the Cost Value Experience decision.

I originally started this Thread as a SD2200D -+ V2 so folks could have a Single Point of Reference for these machines, NOT the Previous ones or the ones after. This was so anyone could come here and share and get info on. When that reached a point to be able to draw up a schematic, then it could be posted for all to use to repair their machines.

OH Well!

Sincerely!
Bill Adams

Not much has been made public regarding these two models (SD2200v2 and GP extreme).

The few souls that have done the hard work required to reverse engineer these detectors are not very likely to
reveal anything just because someone wants them too.

Also, bear in mind that some of us may already be busy with other projects and/or life in general so don't come to the site that often. With a little patience you may eventually see increasing participation.

Have you tried asking at Doug's prospecting forum yet? His site is more specialized to PI and gold units.

At a later time, I will try to answer some of your questions (my apologies for not doing so today)...

[bklein]

bklien, This is the link to the IR N channel Mosfet.

https://ec.irf.com/v6/en/US/adirect/ir?cmd=catSearchFrame&domSendTo=byID&domProductQue ryName=irlml0060trpbf

Guess no one is willing to share on the Original Posts Questions.
If we could pool all the knowledge that is Compartmentalized in different folks experience there would be a schematic and SPECS for these different machines, that could be in ONE Place, not scattered over 3000+ posts and 50 threads.

Just some Basic Info like What is the asked in the original post. This would allow people like bklien, or anyone know what is needed to START the troubleshooting process, and then be able to make an informed decision as to their skill leval as to whether to Attempt the Repair and/or to have it sent off to a Technition for repair. They would be able to make the Cost Value Experience decision.

I originally started this Thread as a SD2200D -+ V2 so folks could have a Single Point of Reference for these machines, NOT the Previous ones or the ones after. This was so anyone could come here and share and get info on. When that reached a point to be able to draw up a schematic, then it could be posted for all to use to repair their machines.

OH Well!

Sincerely
Bill Adams

Bizzare,
I google your number I get lots, I google the original I get 3 items. Somewhere there is something different in the 2 numbers - I don't see it. In any case, it is a 60V part and I am told that this circuit in the GP is for generating 184V so I think they should be 2-300V+ rated parts. No such circuit in the SD2000, correct?