Delta Pulse

[berreizeta]

Hi all,

A expert glimpse, please:

http://www.youtube.com/watch?v=-RYyT20ZLV0

Thanks.

[berreizeta]

FINALLY REPAIRED !!! or maybe....

http://www.youtube.com/watch?v=j6uul9BHu_o

Except: Sound "disappears" when the Threshold is at or near maximum (only speaker, LCD still working right)

(NE555 pin 2 with signal/detection Thresh. at middle = 2.01v, But with Thresh. at max. = 6.84v !! what happens ....??)

Regards
Ger.

[raff33]

???????????????????

[raff33]

Hi ,
please can any one guide me how to connect leads LM337 (adjustable negative regulator) for exact 10.6volts to get more stability ?
many thanks

[berreizeta]

R1 = 220 Ohm
R2 = 1646 Ohm
V = 10.60v


KT315 has a good idea with 7909 (search post).

[ossamaussama]

some idea

http://174.132.129.189/~moreland/for...1&d=1311764490



this make the device more sensitive


because i increase the thresold voltage that make sound in VCO circuit

try this

[kt315]

R1 = 220 Ohm
R2 = 1646 Ohm
V = 10.60v


KT315 has a good idea with 7909 (search post).

eah... it was...

[kt315]

please not write me PM.

do according to the datasheet on the IC. copy the PDF on your hard disc and learn the file for first.

http://pdf1.alldatasheet.com/datasheet-pdf/view/11667/ONSEMI/LM337.html

[raff33]

folks,

I have tested my last mod and was very amazing that it is not working good I was dream. so please do not do this mod with 7909.
stability is great but sensitivity is very low.

yours

Hi kt315 ,
but how you solve the sensivity probleme ?
many thanks again

[raff33]

Hi ,
berreizeta thanks for help ...........
oussama can you explaine more please ?
Regards

[ossamaussama]

clean supply

who have can see using scope

if there is noise in E+and E-

because i think many PI metal detector use power supply circuits that provide clean and stable

+v and v-



but i havent scope

[Jose]

Hello All
Delta Pulse was designed to work without a voltage regulator. Usually the performance is stable and responsive.
Add a regulators to -10.6 volts, requires more voltage "+ E" or keep the batteries fully charged that regulators need a higher voltage than required about 2 volts to operate efficiently. It may be more or less, depending on the specifications of the controller used.
Influence the stability and sensitivity as follows:
Good design and construction of the PCB
appropriate coil
Appropriate damping resistance.
Quality components.
In my case, I got more stability (poor quality of my PCB) making bridges with cables in the line "+ E", "-E" and Mass (midpoint "+ E" and "-E").
Improved stability can be increased to 1.5 k R6, at the expense of losing some sensitivity and adjust the damping resistance. worth a try.
Best Regards
José

[kt315]

Appropriate damping resistance.

no need. DP works on comparatively big strobe first delay value. if you do DP for money hunting and re-tune a timer on 10-12 usec first delay damping resistance re-trimming has the account.

[Jose]

Hi KT315
I write in the forum my particular experience on the Pulse Delta, trying to help and learn what you can, but sometimes what I think I understand, may be far from the truth.
I will consider what you suggested and carried out, new experiences.
Thank you a cordial greeting.
José

[kt315]

Hi kt315 ,
but how you solve the sensivity probleme ?
many thanks again

there was a problem not in sensitivity and stability of the schematic, later I found a bad element battery AA, it was the problem. but to this time I have desoldered 7909. this is why I did think that 7909 does not add the stability.