BARACUDA-Legend-1

[bion]

I dont make measurances in this points,(same coil ) with BF245c detect euro coin at 5 cm and with BF256 the distance is 22 cm.

[Wilson]

Hello Bion, tell me what difference you found between BF245C and BF256, BF256 improved the What?

[mohandes]

[QUOTE=bion;177782]I ended Baracuda. Conclusions: The TL 072 works like the LF 412. With the BF 256 (Q3) is fine, but if we put the BF245C works very bad (triple bad). With an experimental coil diameter 20cm, I can detect a € 1 coin a distance of 22 cm. The Baracuda is much more stable than the Surf PI.

hi can i see your coil and ne5534-6 waves??please

i think bf256 more better than bf245c.
very good
please tell me about your coil ?mkh & ohm?

Edit lease return 180deg Bf transistor

if you have or find oscope can see 250 volt p-p in your coil.
please show me your waves.

[bion]

I ended Baracuda. Conclusions: The TL 072 works like the LF 412. With the BF 256 (Q3) is fine, but if we put the BF245C works very bad (triple bad). With an experimental coil diameter 20cm, I can detect a € 1 coin a distance of 22 cm. The Baracuda is much more stable than the Surf PI.

[bion]

yes it is simple
i have 3 coils but when i measure the flyback voltage not more 150 volts.
be carefull you should have 200 to 250 volts p-p for this detector .
if you have not scope you can measure the frequency by multimeter.look at the schematic that Alex send(in frist page),and see the set point for the ferequency and voltages (+5 &-5 volts),all frequency near 640hz(look frist past please)
for coil you can use tel cable or ...but should have 460mkh and 2.4ohm.
regards

Where i must have 200-220v ???,show me this point and the +-5v please.

[Noemio]

No, mohandes, it’s just because I’m sure that now there are no errors in the board that I’m asking if somebody else finds this spike powering the circuit.

[smity]

Who tried to shield the sensor graphite? What were the results on the ground and in salt water?

[mohandes]

[QUOTE=Noemio;177723]Hi All,

I have to admit that testing a stage at a time has been a good idea.

At first I was disappointed to find out how many “dead” (used) IC’s I kept in my drawer. At the third died 40106 I began to doubt…

After a few attempts I find out that the problem was a damned sneaky spike at pin 5 of ICL7660 at powering. This was lowered replacing electrolytic capacitors, but, as you can see, the as$hole is still there!

I know that a parallel diode can simply solve the problem but I’d like to know if somebody else assembled a CMOS burner instead of a metal detector.

Thank you in advance


hi
first i think you say have problem to find your error on board.
1-when your detector is off , leave all ics then measure your regulator out put.if ok then again off the detector and put the 7660.
then measure your out put.

please take photo your board and under it.

check by beazer mode(diod test) all component and near STREAKs and pins.
and step by step do this.
but first check it

[Noemio]

killer spike

Hi All,

I have to admit that testing a stage at a time has been a good idea.

At first I was disappointed to find out how many “dead” (used) IC’s I kept in my drawer. At the third died 40106 I began to doubt…

After a few attempts I find out that the problem was a damned sneaky spike at pin 5 of ICL7660 at powering. This was lowered replacing electrolytic capacitors, but, as you can see, the as$hole is still there!

I know that a parallel diode can simply solve the problem but I’d like to know if somebody else assembled a CMOS burner instead of a metal detector.

Thank you in advance

[pnp007]

hello pnp
watch your step
is it possible that you wear work protecting shoes with metal
an if you swin right that your right foot is in front (next to coil)

i'm sure no metal present when swing the coil

[mohandes]

yes it is simple
i have 3 coils but when i measure the flyback voltage not more 150 volts.
be carefull you should have 200 to 250 volts p-p for this detector .
if you have not scope you can measure the frequency by multimeter.look at the schematic that Alex send(in frist page),and see the set point for the ferequency and voltages (+5 &-5 volts),all frequency near 640hz(look frist past please)
for coil you can use tel cable or ...but should have 460mkh and 2.4ohm.
regards

[bion]

Heloo Mohandes.
The coil is a simple coil no??? onli 2 wires???

[mohandes]

hi wilson
my big problem is to return the coil
i buy telphon cable(3*2)and winding five turn ,28 cm circle.
my coil became 490mkH and 3.5ohm.
but max voltage thet can be make is 20volt p-p.
can i use cable 2.5(mm^2)
please tell me

[Wilson]

Table Construction of coils

[bion]

Yes missing ICL7660 until tomorow.Thank you Wilson. Muito obrigado.