BARACUDA-Legend-1

[Janou]

Great !

I add video and pictures asap

I'm not sure about the original diamater of the coil, i read 7.5" on the schematic, but seems not the same value on the picture below. I have a wore copper enamelled ( 0.5mm ) and try to find an equivalent with coil calculator ( great stuff ) but no find values closer, so what is your coil internal diameter please ?

[Janou]

No news ?

About the coil, all datas are size of internal coil or external ?

I have all tools but cannot begin before sure about the right size of original coil. Is it a fast coil ?

[bernte_one]

Somebody already finish Baracuda and have more pictures about the project finish ?

http://fotoalbum.web.de/gast/bernd.marten2/Baracuda

http://www.youtube.com/watch?v=tgrjvk1fqfE

[Alexismex]

Janou, coil external measure= 300 mm...........internal 228mm

[Janou]

Thanks for theses links

Alexismex, it's size for housing, not for the coil. In the first schematic i read :

24 turns of SWG26 wire on 7,5 inch form.
7,5" = 190,5 mm, so the number is not between 228 and 300 mm

I just need to be sure, because my housing made in lexan ( polycarbonate ) and i need to build it at the right size.

So the query is simple, i have the right wire, do i use the data from the schematic ( 7,5" Internal diameter ) or a diameter between 228 and 300 mm

( sorry if it's a basic query )

[bernte_one]

dont make housing at first

at first make a coil and then a housing

why?

you can test out the best specs and if you find them you can be sure that you have a coil that best fits to your tasks

smaller coil better for small objects
greater coil better for greater objects

most times i search for coins my coils for this task are not bigger than 25cm diameter

so happy testing

[Janou]

OK thanks, it's clear now ^^

Let's go try with an ID=220mm

Thanks

[Alexismex]

Hello Janou, See in my list of component i put .
COIL diameter 11inch equivalent to 280 mm .
It is the coil i have tested and come with the baracuda it is heavy because it is loaded for the water.
You can make whatsoever you want for the diameter if you respect the resistance and inductance....
Regards

[Janou]

Thanks for this clear answer

[Janou]

I finish the coil with no housing actually : .5mm, 220 internal diameter, 26 turns. I use a part i found i know well to do that.








Actually the Baracuda don't work well, i have bad results with small objects, but i'm sure the main cause is "delay trim" setting. I set correctly the "Offset Balance" ( very simple, results are close with multimeter or scope ) I set the 0 with the output of NE5534 and not 1 pin of LF412 actually. After replaced a faulty 7660 ( instable, now VSS, VSS, VBAT and all power supply are OK ) i try to set correctly the "Delay Trim" but don't find the right method to do this proprely.
I find a rectangular signal ( 52 uS, 5v ) but i just can move it left to right. Have you a method with single chanel scope ?
Before add some cooper on the coil, i need to set correclty this parameter
I build the coil housing next week and take pictures as soon we resolve this issue ^^

[6666]

Janou thats an interesting coil former, I have not completed my Bara yet, but I first made the power supply, and I also have a faulty 7660, it will not start every time I apply power
also when making the Bara make sure the Cap on the out put of the 7660, that's pin 5, is the 25 volt cap, the other two can be 16v.

[Qiaozhi]

Janou thats an interesting coil former, I have not completed my Bara yet, but I first made the power supply, and I also have a faulty 7660, it will not start every time I apply power
also when making the Bara make sure the Cap on the out put of the 7660, that's pin 5, is the 25 volt cap, the other two can be 16v.

I've noticed a few people here are having problems with the 7660.
You need be aware that there are two versions of this IC - the 7660 and the 7660A.
The 7660 performs supply voltage conversions from positive to negative for the input range of +1.5V to +10V, and the 7660A has an input range of +1.5V to +12V.
The maximum supply voltages are also:
7660 = +10.5V
7660A = +13.0V

[bernte_one]

I've noticed a few people here are having problems with the 7660.
You need be aware that there are two versions of this IC - the 7660 and the 7660A.
The 7660 performs supply voltage conversions from positive to negative for the input range of +1.5V to +10V, and the 7660A has an input range of +1.5V to +12V.
The maximum supply voltages are also:
7660 = +10.5V
7660A = +13.0V

was the problem on my first selfmade bara too

too all electronic newbies like me:
everytime you buy components by your own check the datasheets if not 100 % shure

[smity]

7660CPAZ = 10 V
7660SCPAZ = 12 V

[Janou]

My coil former come from a laboratory apparatus

I add somes informations about primary testing with a simple voltmeter if somebody have a problem. ( I use the Rev .D schematic with 20k delay trim and 8 NiMh battery )

Vbat = 9.92V ( pin 8 of U7 )
Vdd = 4,97V( pin 8 of U4 )
Vss = - 4,94V ( pin 7 of U1, pin 4 of U4 )
Vout = 9,86V ( pin 5 of U7 )
Vcc+ = 4,67V ( pin 7 of U7 )
Vcc- = -4,94V ( pin 4 of U7 )

Pin 13 of U1, between 0 and 130 mV ( min/max of delay trim )
180 mV accross coil ( probably not the real value )

Actually i already change U7 ( instability at Vout ) and change U1 but change sound little different but nothing else. I find 2€ coin at 10 cm when i try several setting with "Delay trim", so poor results because i don't understand the right method to set correclty "delay trim" with a mono trace scope.