Surf PI Pro

[porkluvr]

Make sure the LM358 is not installed backwards.

edit: Never mind the 358 orientation, but look at this:

If you have +5V at NE5534 pin-7, you should also see +5V at LM358 pin-8. They're supposed to be connected.
You must be able to measure very low resistance between those two pins, if not then you may have an open trace or bad solder.

Oh, yes I rounded 4.97 up to a 5 (I like things simple).

[sdesic]

look for GND connection that you mentioned before
try to power up and measure voltages on IC sockets -5V and +12V

[Mohamed Ghitas]

i removed all ics except 7660 and nothing happens shall i measure the pins now ??
if yes which pin shall i measure ??

[Mohamed Ghitas]

my Readings without coil
7660
pin 1 :1.75 v
pin 2: 2.43
pin 3:0
pin 4:-2.29
pin 5 :-4.59
pin 6 :0.75
pin 7:5.02
pin8 : 4.97

4093
pins 11,3,4 all -4,37V
pin 10 :4.67

4066 has 5V on pin 14
4066 has -4,59V on pin 6, 8, 9 unused part
4066 has -4,59V on pin 7
and when i measure pin 11it gives beeb

358 has -3.92V on pin 8
358 has -4.95V on pin 4

NE5534
pin 1 :3 v
pin 2: 0
pin 3:0.01
pin 4:-4.62
pin 5 :-0.51
pin 6 :0.06 "can control by offset"
pin 7:4.97
pin8 : 2.91

NE555
pin 1 :0 v
pin 2: 6.35
pin 3:10.69
pin 4:12.34
pin 5 :8.23
pin 6 :6.35
pin 7:6.35
pin8 : 12.32

[Mohamed Ghitas]

okay i removed the coil and measuring the ics now

[sdesic]

did you check orientation of your NE555 ?
you need to pop out all ICs except 7660 and try voltages and then with NE555 same thing
can you try measuring without coil also and before you pop them out (ICs)

[Mohamed Ghitas]

i don't have any sound until i touch the mpsa13 base with the multimeter and the sound increase when i touch the mosfet in same time with my hand

but there is something strange happens now i unplugged the power and trying to measure the points i found that the GND and +5, +12 all are short circutied with GND
555 all pins are connected to the GND except pin 2,6,7
76605 pins 3,5,7,8 also connected to GND

is this is normal ??

the pots gives no response only the volume and offset they made some changes in sound and in pin 6 of NE5534

[Mohamed Ghitas]

not working

my Readings is
7660
pin 1 :1.75 v
pin 2: 2.43
pin 3:0
pin 4:-2.29
pin 5 :-4.59
pin 6 :0.75
pin 7:5.02
pin8 : 4.97

4093
pins 11,3,4 all -4,37V
pin 10 :4.67

4066 has 5V on pin 14
4066 has -4,59V on pin 6, 8, 9 unused part
4066 has -4,59V on pin 7
and when i measure pin 11it gives small beeb

358 has -3.92V on pin 8
358 has -4.95V on pin 4

NE5534
pin 1 :3 v
pin 2: 0
pin 3:0.01
pin 4:-4.59
pin 5 :-0.43
pin 6 :0.14 "can control by offset"
pin 7:4.97
pin8 : 2.91

NE555
pin 1 :0 v
pin 2: 6.25
pin 3:10.49
pin 4:12.12
pin 5 :8.09
pin 6 :6.24
pin 7:6.23
pin8 : 12.07

i replaced delay 10k pot with 50k pot
and placed 200 Ohm on the 3906 emitter
iam using coil with diameter 125mm ,0.4 ,19 turn

here is my circuit


thanks in advance

[Mohamed Ghitas]

thank you very much Carl-NC its very nice to reply me ^_^

i have made the circuit but it didn't work :\
so could you please tell me where the points to check with multimeter to know if the circuit is working or not ??

thanks in advance

[Carl-NC]

1. Yes, that's fine.
2. Electrolyte will probably work OK. 250v ceramic will also work.
3. 1/8W is fine. I would put the 22k in R20, probably will make the threshold a little sensitive but should work.
4. Caps should be fine.

[Mohamed Ghitas]

iam having some problems if any one could help me please

1- R36 is "12 Ohm" can i replace it with 10 Ohm 1W resistor

2- C7 which is 1uf can i replace it with electrolyte one it has + and - , if no i have another one 1uf ceramics but 250v large size is it ok ?

3- for R20 & R18 which are 47K can i replace one of them with 22K and the other is 47k but 1/8 W is it ok ??



4- the capacitor i used is small as shown in fig so i think its low power is it ok or shall i change them ??



please i need fast answers i must finish this detector as soon as possible

thanks in advance
Mohamed Ghitas

[sdesic]

you need to be in 250-350uF range so you need more turns
18-21 turns...

it is best to try with 21 and than measure depth you get with that coil and remove turn or two and measure again

[Mohamed Ghitas]

seems that iam going to use coil wit diameter 250mm, 0.4 thickness, 13 turns
my question is how to know the required or best uH needed ??

[Qiaozhi]

My fault
did not read ... I assumed it was diameter

417uH is still a bit more than required....
is it mH (miliHenry) or microH

than we got hacked ... by Mr.501

The result is shown in mH. Therefore 0.417mH means 417uH.
If your trying to get to 300uH, then try either 20 or 21 turns.

The hacker first gained access on September 11th (911) and launched the attack on the 12th. Today is Friday the 13th.

[sdesic]

My fault
did not read ... I assumed it was diameter

417uH is still a bit more than required....
is it mH (miliHenry) or microH

than we got hacked ... by Mr.501