Tweet
Originally posted by Tim
View Post
-
Thats not bad, anybody nutted out the schematic yet ? -
9.8" coil as it is my standard housing size (mono polo) no shield and tight bound but not bonded single strand teflon 26 awg 23 turns for 368uh so not the best coil but not bad i await the posh litz to try!Comment
-
Sheesh! That's not looking good. I hope someone can get better performance. 2 ounces of pure silver@8inches???Originally posted by qute1 View Post
Something is seriously WRONG there.....settings I suspect.
dbanner says "a toy" - even the most pathetic toy detectors are better than that !!!Comment
-
Yes, I've back-engineered the schematic. Since seeing gtdavid's efforts, I wanted to create the schematic using KiCad. The Software Manager for Linux Mint had version 4, but I noticed that gtdavid was using version 5. Consequently I now have version 5.0.0.-rc1-44a33f2-62-ubuntu16.04.1,release build loaded on my computer. However, I won't be able to do anything with this for at least 2 weeks, but after that I will post the details here once I can get my head around how KiCad works. Unfortunately the documentation hasn't kept pace with the software, so some things do not work as expected. The libraries are a case on point.Originally posted by 6666 View Post
As far as the design is concerned there's nothing surprising here.
The circuit is protected from someone connecting the battery back-to-front by a series diode. The 5V supply comes from a linear regulator, and there are no switching regulators. The Microchip PIC (16LF1825) drives the MOSFET (IRF740S) via an npn transistor (BC847). The preamp is based on a TL072 with 2-stages of ~1000x and ~25x. So there's a huge gain at the input to the 10-bit ADC to make up for the lack of resolution. Audio output is generated by the PIC. Three tactile switches are read by the PIC to control the menu system, and the display is a Nokia 5110 LCD (84 x 48, 4032 pixels). Transmit pulse rate is 175pps.
As you can see, this detector is a demonstration of what you can do with a just a few components, although [admittedly] some of these have hidden complexity. It is not a deep detector, nor is it a detector suitable for searching for gold nuggets. I guess it's really a small inexpensive, not power hungry, beach (holiday) detector. It's also non-motion, and there's no Earth field elimination.
Anyway, it's an interesting device for a cheap price. It also works much better than I was expecting, so kudos to the designer.
Comment
-
Thanks for the summary.Anyway, it's an interesting device for a cheap price. It also works much better than I was expecting, so kudos to the designComment
-
BTW even if its hand drawn on a napkin is fine
Comment
-
Very interesting. Not bad for the price, and as you said, good for holidays at the beach for not so deep targets. Don't want to be digging too deep while sipping cold beverages. Cheers and congrats to Prince Harry, me being from the Commonwealth.Originally posted by Qiaozhi View PostYes, I've back-engineered the schematic. Since seeing gtdavid's efforts, I wanted to create the schematic using KiCad. The Software Manager for Linux Mint had version 4, but I noticed that gtdavid was using version 5. Consequently I now have version 5.0.0.-rc1-44a33f2-62-ubuntu16.04.1,release build loaded on my computer. However, I won't be able to do anything with this for at least 2 weeks, but after that I will post the details here once I can get my head around how KiCad works. Unfortunately the documentation hasn't kept pace with the software, so some things do not work as expected. The libraries are a case on point.
As far as the design is concerned there's nothing surprising here.
The circuit is protected from someone connecting the battery back-to-front by a series diode. The 5V supply comes from a linear regulator, and there are no switching regulators. The Microchip PIC (16LF1825) drives the MOSFET (IRF740S) via an npn transistor (BC847). The preamp is based on a TL072 with 2-stages of ~1000x and ~25x. So there's a huge gain at the input to the 10-bit ADC to make up for the lack of resolution. Audio output is generated by the PIC. Three tactile switches are read by the PIC to control the menu system, and the display is a Nokia 5110 LCD (84 x 48, 4032 pixels). Transmit pulse rate is 175pps.
As you can see, this detector is a demonstration of what you can do with a just a few components, although [admittedly] some of these have hidden complexity. It is not a deep detector, nor is it a detector suitable for searching for gold nuggets. I guess it's really a small inexpensive, not power hungry, beach (holiday) detector. It's also non-motion, and there's no Earth field elimination.
Anyway, it's an interesting device for a cheap price. It also works much better than I was expecting, so kudos to the designer.Comment
-
Thanks all for your interest in this, especially Qiaozhi for his effort.
Comment
-
The next obvious step is to see whether a new front end design can be developed that plugs right into the same micro, if that is at all possible. Maybe not.Comment
-
Any new on mods or improvements for the impulse?Comment
-
Not yet. Just got back from holiday, and trying to find time to get Kicad up and running.Originally posted by qute1 View PostComment
-
nice to know hope you had a good holibob.Comment
-
mine works good enough, what did you expect from such a small circuit?
by playing with pulserate und delay Timing you can get small Separation of iron based objects and non-fe Targets
tried with a 35cm diy monoloop coil
i gues i can achieve better results with basket or planar coil
but it is not on me to make promotion for this detector, the designer should do thisComment
-
Schematic of Impulse2 PI
Here's the schematic of the Impulse2 PI (see PDF attachment).
I originally tried to match the reference designators to the PCB, but ended up with some conflicts. Also, there were some components with no associated silk screen, so I gave up and auto-numbered the symbols.Comment
-
Thanks Q .Comment
Comment