Surf PI 1.2 problems

[Boelslair]

Hi there,

I have just assembled one of my two surf pi kits.

I am able to tune the offset just fine, but I get no sound.

I just get a slightly buzz form the speaker. The buzz are getting louder if I move the coil towards the board but nothing else.

I have replaced all IC’s with the ones from the other kit – same result.

Do you have any ideas?

/Jakob

[Boelslair]

I have now assembled the other board with the same result - I guess it is either my powersupply or my coil.

I am using a 9v battery which I fugured would be fine since the board is running 5v

My coil is Ø246 21 turns of 0,4mm enameled copper wire.

/Jakob

[Qiaozhi]

I am using a 9v battery which I fugured would be fine since the board is running 5v

The Surf-PI needs a 12V supply.

[localbug]

The Surf-PI needs a 12V supply.

mine works with 9v

[Qiaozhi]

mine works with 9v

It probably does work at 9V, but (if you look at the schematic) it's designed to operate from 12V. You should find a depth advantage by operating at the higher voltage, and you'll be able to drain more energy out of the batteries before they need to be replaced. The 78L05 regulators have a typical dropout voltage of 2V, so your 9V battery will only need to drop to 7V (that's 1.17V per cell) before the detector starts to become unstable. With a 12V pack the cell voltage can drop to 0.875V.

[localbug]

I get your point thanks qiaozhi ,

There's something confuse me. 4066 gate control pin is it going to work with negative voltage?? because the output from 4093 all negative (-4.7v) in my case.
couldn't detect any metal just a hum from buzzer.
so I have to short pin 5 and 13 (4066) with C10 and C12 to get +5v and it worked.

[chemelec]

Not ALL of the Surf operates on 5 Volts!
The Oscillator, Coil driver and Coil are supposed to Operate at 12 Volts.

[localbug]

Not ALL of the Surf operates on 5 Volts!
The Oscillator, Coil driver and Coil are supposed to Operate at 12 Volts.

Hi Chemelec I like your website very informative,
I was talking the control voltage for the 4066 from what I know its high (5v) and low (0v) to open and close the gate.
I was confused because 4093 output pin 3, 4, and 11 all negative (-4.7v) to control the gate and that makes my detector didnt pick up any metal target. but seems like most people has no issue with their surf pi.

[chemelec]

I Built the Surfer Many Years ago, Just for fun, But haven't used it since than.

I would need to find it, and fire it up to verify what really occurs on the 4093 and the 4066, after it.
But the surfer I built Does work OK.

Hi Chemelec I like your website very informative,
I was talking the control voltage for the 4066 from what I know its high (5v) and low (0v) to open and close the gate.
I was confused because 4093 output pin 3, 4, and 11 all negative (-4.7v) to control the gate and that makes my detector didnt pick up any metal target. but seems like most people has no issue with their surf pi.

[Qiaozhi]

There's something confuse me. 4066 gate control pin is it going to work with negative voltage?? because the output from 4093 all negative (-4.7v) in my case.
couldn't detect any metal just a hum from buzzer.
so I have to short pin 5 and 13 (4066) with C10 and C12 to get +5v and it worked.

Have a look at the Surf-PI schematic (attached). You will see that ICs 4 and 7 are both driven from +/- 5V, so there should be no problem with the circuit. Perhaps there's a mistake in your PCB layout.

[WM6]

Qiaozhi, you posted to low resolution, to recognize something.
Do you have this in better resolution?

[Qiaozhi]

Qiaozhi, you posted to low resolution, to recognize something.
Do you have this in better resolution?

That's strange. The original is not that small, and should have been 122.3kB.
Here it is again as a png file.

[localbug]

Really appreciate if someone could post their voltage output pin 3, 4, 11 (4093) from surf pi 1.2 successful build.

Qiaozhi I'm using PCB board from silverdog

[localbug]

I was thinking pin 3 and 4 (4093) need to have 1nF cap to convert the signal to positive


here's a pic what I did to make mine working






another alternative is to short pin 1 wth pin 2 also pin 3 wth pin 4 (4066) so the gate will open 24/7 just like Mcdonalds....

[localbug]

VSS pin 7 4093 supposed to ground right??