Arduino Nano VLF Metal Detector Project - Main Discussion

[Qiaozhi]

ok i have traced it to Q1 i replaced it now i have - voltage after R18 the signal is low i was thinking the voltage is to low for it to switch the transistor how about instead of a 10K put say a 1K just to make sure its switching ?

You can easily check if the sync pulse is getting to the LT1054s by connecting the scope to pin7 on either U2 or U3.

[kosacid]

ok i have traced it to Q1 i replaced it now i have - voltage after R18 the signal is low i was thinking the voltage is to low for it to switch the transistor how about instead of a 10K put say a 1K just to make sure its switching ?

[kosacid]

hmm I'm having problems to with the LT1054 no negative supply

[Qiaozhi]

I'm up and running something no one has mentioned what's the cheapest coil I'm in the uk, I have it running on a garrett 150 coil is there any cheaper coils than that

The cheapest place to buy a second-hand coil is on eBay. The unbranded Chinese coil on page 128 is the cheapest new coil, again on eBay.
The only problem with the Chinese coils is that they keep changing the model number. There's one on the UK eBay site at the moment for an MD6350 at £52.79, but it doesn't state the size.
Also, there's some knock-off copies of the Fisher F2 coils.

[kosacid]

I'm up and running something no one has mentioned what's the cheapest coil I'm in the uk, I have it running on a garrett 150 coil is there any cheaper coils than that

[Qiaozhi]

I did have a problem with the footprint of c10 c30 c41 the last 2 are fine but I can't find caps to fit the footprint so they are sitting on top my question is there ones that fit that footprint?

These capacitors are fairly standard types with a 5mm pin spacing.
Here's an example from Farnell:
https://uk.farnell.com/kyocera-avx/s...ial/dp/2332992

[MartinB]

I did have a problem with the footprint of c10 c30 c41 the last 2 are fine but I can't find caps to fit the footprint so they are sitting on top my question is there ones that fit that footprint?

Switch Electronics in Hull. Collections — Page 52 — Switch Electronics | Your One Stop Component Shop
You can select by value, physical size and pitch.
They should get them to you in a couple of days

[kosacid]

I did have a problem with the footprint of c10 c30 c41 the last 2 are fine but I can't find caps to fit the footprint so they are sitting on top my question is there ones that fit that footprint?

[Qiaozhi]

Need Help Building a Verified LT1054 Voltage Converter

Hi everyone,
I’m still really stuck trying to get my negative voltage rails working with the LT1054. I’ve replaced all the chips and checked everything, but I still can’t generate a stable negative supply.

Could someone please build and test just the voltage-converter portion for me on a board and verify it works? I’d be able to pay for your time and cover shipping if that’s possible.

Thanks so much!
- Ronin

What are you seeing on the scope at the collector of Q1?
Are you sure there is a sync pulse there?
Depending on the origin of some of these transistors they may have different pinouts than expected.

[Ronin0000]

Need Help Building a Verified LT1054 Voltage Converter

Hi everyone,
I’m still really stuck trying to get my negative voltage rails working with the LT1054. I’ve replaced all the chips and checked everything, but I still can’t generate a stable negative supply.

Could someone please build and test just the voltage-converter portion for me on a board and verify it works? I’d be able to pay for your time and cover shipping if that’s possible.

Thanks so much!
- Ronin

[kosacid]

there is a lot to go through in the book its going to take me ages to read through its easer if it on screen for me

[kosacid]

no just letting people know that's all you need to compile the project that's all

[Qiaozhi]

i only seen the paper one forgot to say add the U8g2 library for the oled

Are you saying that the requirement to load the U8g2 library is not mentioned in the book?
The procedure is described on page 67.

[Ronin0000]

Yes I am using a 12v DC external power supply connected to the input.

[Qiaozhi]

The arduino nano that I am using is not a offical one. Should I buy a offical one and test it with the circuit?

That shouldn't be a problem. The ones I have are clones from AZ-Delivery.
The output from the Arduino Nano should be +5V.
I assume your are using either an external power supply or battery pack, and not a USB supply connected to the Arduino?