Barracuda pi question

[gogi]

Hi. I am new to metal detecting, i don't know nothing much about electronics. I bought the cuda from siverdog. Made a 21 turn 30cm coil with 0.5mm wire. It is working. Not wery deep field but coin is detected from 19cm. I will make a few coil design so i can take the best. I read much abaut the cuda on this site, and there are post about voltage, 9V or even 12V operating. I put a 6V battery pack and it is working like mentioned above. Also try 9V and nothing changed that i notice. So my question is if it is running on 6V is that ok? Or i am missing something.
Thank you

[jladre]

Hi. I am new to metal detecting, i don't know nothing much about electronics. I bought the cuda from siverdog. Made a 21 turn 30cm coil with 0.5mm wire. It is working. Not wery deep field but coin is detected from 19cm. I will make a few coil design so i can take the best. I read much abaut the cuda on this site, and there are post about voltage, 9V or even 12V operating. I put a 6V battery pack and it is working like mentioned above. Also try 9V and nothing changed that i notice. So my question is if it is running on 6V is that ok? Or i am missing something.
Thank you

Just follow what the design so that you will not mess something.. It is just like putting scotter engine on a big bike.

[gogi]

Ok. I will make coil for the cuda like it should be. Thank you. What about voltage? Should i use 6v,9v, or 12 v?

[kt315]

12 Volts.

[FatBob]

Your coil may have too much capacitance. Try a coil like this;

For making mono homebrew PI coils, nothing beats the old-fashoned AWG 22 to 24 stranded PFTE hook up wire wound in a 10.5" diameter coil
with 21 to 22 turns covered with a spiral wrap and 3M 1190 copper fabric tape to act as the shield.

[gogi]

Ok. Thank you very much all.

[Koala]

Careful which 7660 you used some only have a max voltage of 12 volts others are 15 volts. If you are using the 15v version you are okay to use 12v supply however if your 7660 is the 12v version then using 12v is asking for trouble 10v would be safe but short run time.

[ODM]

It is important to check what your battery's peak voltage after charging is, with a voltmeter. As long as your battery does not peak over the ICs rated voltage you are safe. Find the exact datasheet (same manufacturer, same letter code) to find out your 7660s voltage limit. Use maximum recommended, not absolute maximum!

This can be over the 12V rating of the IC. Unlike lightbulbs, voltage limits for ICs can be very precise.

[darkfibre]

It is important to check what your battery's peak voltage after charging is, with a voltmeter. As long as your battery does not peak over the ICs rated voltage you are safe. Find the exact datasheet (same manufacturer, same letter code) to find out your 7660s voltage limit. Use maximum recommended, not absolute maximum!

This can be over the 12V rating of the IC. Unlike lightbulbs, voltage limits for ICs can be very precise.

Thanks for this information. I have ordered a few different kits and intend to use 18550 lithium batteries. I will do some tests on 3 and 4 cell configurations.

[kt315]

you have to order especial board for protection-charging of 18550's too. do you know about that fact???

http://www.ebay.com/itm/4A-5A-PCB-BM...sAAOSwQTVWALGV

[darkfibre]

I have a dedicated charger that will charge the cells individually that can also cycle (charge/discharge/charge) and report on each cells mAhour rating.

Edit; google SKYRC MC3000

[gogi]

Careful which 7660 you used some only have a max voltage of 12 volts others are 15 volts. If you are using the 15v version you are okay to use 12v supply however if your 7660 is the 12v version then using 12v is asking for trouble 10v would be safe but short run time.

Absolute max ratings, supply voltage +13v. So 12v should be good?