Surf PI Pro

[mschmahl]

@ ossamaussama

Thank´s for your Posting

i have made surf pi pro

it works but the delay have no effect
so i return to the older version of surf pi

and put 100 ohms between the emitter of 2n3906 and the +12 and also change 1K yo 100 ohms ( resistor between -5 and the collector)

delay pot changed to 100k
only now the delay have effect and you can ignore pull tap and cigarette box

With this data could i fix my Delayproblems.

[mschmahl]

Okay, you are right. Then the failure is on an other part.

[oldfox]

I think pin 8 and pin 9 of the 4093 must be exchanged. Then the pot has an effect.

The 4093 is a Quad 2 input NAND gate. Swapping the 2 inputs will have absolutely no effect on the output. 1+1=0 0+1=1 0+0=1 1+0=1

[mschmahl]

I think pin 8 and pin 9 of the 4093 must be exchanged. Then the pot has an effect.

[ossamaussama]

i have made surf pi pro

it works but the delay have no effect
so i return to the older version of surf pi

and put 100 ohms between the emitter of 2n3906 and the +12 and also change 1K yo 100 ohms ( resistor between -5 and the collector)

delay pot changed to 100k
only now the delay have effect and you can ignore pull tap and cigarette box

[ossamaussama]

yes it will note work if any metal under the coil

because of saturation

test the device far away from ground ( may contain metal pipe ....)

[oldfox]

Dito
Do the normal Bernte, diconnect pwr supply, get that up and running, place current limiters on your supply outs and go from there, your main 12v supply doesnt take prisoners so worth double checking what that feeds diodes caps chips.
Personaly id deplug the chips and fire it up and see what it draws, should be very low current, if its high then you can fault find without to much further damage.
A tip.. in fucture on a new build maybe worth connecting a diode accross the positive and negitive and a 800ma fuse inline with positive so if you get polarity wrong by accident as you did you will just blow the fuse with no further damage.


All the best
Dave

Or try this... Place a 4 lead bridge rectifier in the power-in lines. That way battery polarity won't matter and you can even power up on the bench with AC power. Good luck.

[wl4d]

don't work

I finished project and switched on it was 0,5 sec tone then nothing. I tried to tune pots but no change at all. I measured voltages on 4066 and 4096 between pins 14 and 7 and U= 9,68V.
78l05 gives 5.12V and 7066 -4,86. When I put speaker on coil output I hear loud tone which means that stage works well. Where could be error? How to measure ne5543 ofsset voltage?

[wl4d]

Treshold potentiometer

Hey guys I am new on this great forum, I hope that u can help me fast about this MD.
I am confused about that treshold potentiometer, is that multiturn pot for fine tuning or ordinray pot with switch? If is that one with switch how to wire it to PCB? IT has 3 ends for pot and 2 for switch. Thanks

[bernte_one]

yes
i simple fuse can save lifes a some euros

thanks for answer

[satdaveuk]

hello

yesterday i want to finisch my second seurf pi pro but at first test i misplace + and - power supply arrgh

the came up some magic smoke around ne555 but elkos around are not broken
detector dont work at second test with right +and - connection and changed ne555

i suppose some other parts are blasted in to heaven

has anyone an idea at which parts i should start repair (diodes and elkos?)

many regards

p.s. most mistakes i make when it is later at night and i look not twice on each installed component before test

Dito
Do the normal Bernte, diconnect pwr supply, get that up and running, place current limiters on your supply outs and go from there, your main 12v supply doesnt take prisoners so worth double checking what that feeds diodes caps chips.
Personaly id deplug the chips and fire it up and see what it draws, should be very low current, if its high then you can fault find without to much further damage.
A tip.. in fucture on a new build maybe worth connecting a diode accross the positive and negitive and a 800ma fuse inline with positive so if you get polarity wrong by accident as you did you will just blow the fuse with no further damage.


All the best
Dave

[bernte_one]

hello

yesterday i want to finisch my second seurf pi pro but at first test i misplace + and - power supply arrgh

the came up some magic smoke around ne555 but elkos around are not broken
detector dont work at second test with right +and - connection and changed ne555

i suppose some other parts are blasted in to heaven

has anyone an idea at which parts i should start repair (diodes and elkos?)

many regards

p.s. most mistakes i make when it is later at night and i look not twice on each installed component before test

[bernte_one]

hello

with 24cm dia coil i got 2e coin with lightthreshold and full gain up to 34cm in air
i think that our projects here aren´t toys they works great
the damping resistor is ok as in plan but anybody can do this better with scope
but for me the results are ok i use 390R 1% 1W resistor coil resistance under 2R

[smaeel]

@smaeel
try to use i cable with bigger diameter 0,5mm+, litz or monocore wire (to lower the resistance for more power)
with insulation (the insulation at the enamled copper wire is to thin)
do not bundle the cable too tight let some fresh air between the cables
the coil can better breath äh i mean charge/ discharge - so faster pulses and better performance are possible

regards

Hi bernte_one
Thank you for your reply
Do you know the "damping resistor" calculation if I change the coil resistor ? Does not matter?
I don,t think the original "White's" using wires with more space between or with thick insulation as I see the pictures of original coil in the net , because this causes bigger size than what I see in the pictures.
I'll be very grateful if you put a picture or dimentions of your coil and the maximum depth of a coin sensitivity.
I know this device is not more than a toy for hobby and there was not much expected.

[bernte_one]

have produced success.The detector can distinguish between the cap / aluminum foil and cans pull ring.

11

how or where should i connect this circuit to surf pi pro board

or is this only a mod on the current board???

regards


ah moment is it parallel to the audio output? can anyone translate the russian comment on the picture(at the switch)