New Bipolar Boost TX and Front End

[KingJL]

Looking super good! Thinking I will be ordering carbon fiber shaft set next week.

@Mdtoday, what is the outside diam of the shaft for the housing as designed. I cannot find any of the diameter specs for the shafts offered by different suppliers. They only designate the shafts by machine... e.g Equinox, Whites TDI, etc. I am looking at 2 suppliers: (1) that you supplied for Detech Chaser shaft, and (2) Steve's Detector Rods for the Equinox. I really like the system offered by Steve's Detector Rods (with the counter weight option). But as of yet, I have no indication of their outside diameters.

[KingJL]

Positioned and added hole on front panel for power toggle switch.

[ATTACH]47697[/ATTACH]

Up out the way with a clear routing path to the 2 pin connector on power module and in a position that won't get in the way of encoder usage

[ATTACH]47698[/ATTACH]

Next thing is the audio connector a 3.5mm panel mount jack

Looking super good! Thinking I will be ordering carbon fiber shaft set next week.

[Mdtoday]

Positioned and added hole on front panel for power toggle switch.



Up out the way with a clear routing path to the 2 pin connector on power module and in a position that won't get in the way of encoder usage



Next thing is the audio connector a 3.5mm panel mount jack

[Mdtoday]

Added cut-outs for TX/RX cable(s) on bottom side of electronics enclosure and one opening on the back side for power.




The TX /RX is routed directly down through the handle .



The +20, +5 and GND is routed to power supply on back panel.

[Altra]

There are some fake Panasonic branded cells out there (surprise) but you can tell the real Panasonic cells as there is a Matrix barcode just visible under the plastic sleeve.

I have original Panasonic's and you are right I can see the markings under the sleeve. I have some of the low grade "Ultrafire" cells and they seem to be lighter in weight. I don't have a small scale to confirm. Now that E-cigs are the rage you can find real Panasonic's on ebay. I paid about $14 for two NCR18650B from Florida. If you suspect fakes, file a complaint with eBay and you will receive a refund. Do not buy from China or their local warehouses.

Found this a while back and it doesn't build confidence

https://www.aliexpress.com/item/32876306672.html?spm=a2g0v.10010108.1000001.11.7d904d9c88jMiE

[Mdtoday]

Yes, the quality of some cells leaves a lot to be desired for sure.

I use Panasonic NCR18650B cells and purchase from this seller in Australia. Quality and reliability of these units is excellent.

https://www.ebay.com.au/itm/Panasonic-NCR-18650-B-3400mAh-3-7v-FLAT-TOP-Lithium-Li-Ion-Rechargeable-Battery/302950417180?hash=item468940831c:m:mn21bwU-KCyzzMTj35_43Sw&var=601872684818

The charger I use is a Nitecore AC/DC multi-cell unit also available from the same seller.
https://www.ebay.com.au/itm/Nitecore...cAAOSwm-FcPbIJ

There are some fake Panasonic branded cells out there (surprise) but you can tell the real Panasonic cells as there is a Matrix barcode just visible under the plastic sleeve.

[Mdtoday]

@Mdtoday, do you have a battery/source recommendation as the quality of some of the offerings are all over the map.

Yes, the quality of some cells leaves a lot to be desired for sure.

I use Panasonic NCR18650B cells and purchase from this seller in Australia. Quality and reliability of these units is excellent.

https://www.ebay.com.au/itm/Panasonic-NCR-18650-B-3400mAh-3-7v-FLAT-TOP-Lithium-Li-Ion-Rechargeable-Battery/302950417180?hash=item468940831c:m:mn21bwU-KCyzzMTj35_43Sw&var=601872684818

The charger I use is a Nitecore AC/DC multi-cell unit also available from the same seller.

https://www.ebay.com.au/itm/Nitecore-D4-Intelligent-Standard-Battery-Charger-Li-Ion-AA-AAA-18650-Home-Car/302375074386?epid=1529890100&hash=item4666f57a52:g:XDcAAOSwm-FcPbIJ

[Mdtoday]

Just wondering did my pm make it ?

Yes, thanks 6666, you should see the pcb coil soon.

[KingJL]

... Here is the latest revision of the Power module showing updated values for R2, R3 and R5...

@Mdtoday, do you have a battery/source recommendation as the quality of some of the offerings are all over the map.

[KingJL]

Here is the latest revision of the Power module showing updated values for R2, R3 and R5.

[ATTACH]47684[/ATTACH]

R3 I calculated to be 73k2 - 75k to trim output to 20v, with 73k2 fitted voltage is 20.35.

R5 value should be 2k2 - 2k7 depending on voltage range required..

R2 should remain at 1M2.

JL, I have 2 units ready to send with the above values fitted, I should be able to get them off before weeks end.

The values used are very satisfactory. The 2K2 value for the R5 should be the correct value... not so much for the range (the range provided by the 2K7 should be sufficient), buy I have noticed that most 805 SMD resistor kits omit the 2K7 and 4K7 values... they wil go from 2K2 to 3K3 and 3K9 to 5K.

[6666]

Your welcome 6666, PM me with your postal address and I'll get them to you in the next few days

cheers

Just wondering did my pm make it ?

[Mdtoday]

Here is the latest revision of the Power module showing updated values for R2, R3 and R5.

Power Supply Rev 2_20.pdf

R3 I calculated to be 73k2 - 75k to trim output to 20v, with 73k2 fitted voltage is 20.35.

R5 value should be 2k2 - 2k7 depending on voltage range required..

R2 should remain at 1M2.

JL, I have 2 units ready to send with the above values fitted, I should be able to get them off before weeks end.

[KingJL]

... I was thinking of Bluetooth as that is what I use, just makes operating the detector so much easier, I will work on ideas along that line...

I have been using this paired with over-the-ear bone conductor BT 5.0 headphones... for me, it is multi-functional... I use it for my entertainment center and for my metal detectors. I have a patch of velcro on the BT TX and on each of the units that I use it with and use a short 3.5mm audio jumper cable to connect between the device and the BT TX. I have found it to be a most satisfactory BT solution. The key is to make sure that what ever you use, make sure the BT TX is using BT 5.0 for low latency (same goes for whatever headphone you use).

[Mdtoday]

I agree... a very acceptable solution. A point while we are discussing the 5 pin coil connector... a reminder that the TX (and RX if used for IB) are "floating"... meaning that neither end of the coil can be connected to actual GND. If an actual grounded shielding is desired, it will require a cable with a 3rd (or 5th for IB) conductor for the ground, which could be connected to pin 3 of the connector (and case ground). I think we can include the RC low-pass filter for the audio PDM signal right on the audio connector (PMOD J4, pin9 to a 330 ohm to tip of audio connector with a 56n capacitor between audio connector tip and sleeve). Your thoughts? Forgot to mention that the audio output is high impedance (600 ohm or greater)... should work well feeding a bluetooth TX!I cannot open the attachments... I get the following message ..."Invalid Attachment specified. If you followed a valid link, please notify the administrator".

Sorry about that, I was editing the post as the image on one was black for some reason, so probably why it was invalid.

Yes, I think the RC low-pass filter components will be fine in the suggested position.
I was thinking of Bluetooth as that is what I use, just makes operating the detector so much easier, I will work on ideas along that line.

The ground plane on the connector board is isolated and can be wire linked to connector housing , so yes just used as screen if required .
The probe/coil switch board TX/RX circuit is floating I added a ground plane to pin 3 so we had some wiggle room to solder a screen wire from the connector board if required.

The other 4 x solder pads around the edges of both boards are also isolated and are included with the intention to add tinned copper wire legs for stability, again if required.

[KingJL]

I cannot open the attachments... I get the following message ..."Invalid Attachment specified. If you followed a valid link, please notify the administrator".

Links are working now. Arm rest looks great!