Delta Pulse

[ossamaussama]

to remove the effect of feed back network on delay


this work with small coil 28 cm

not with large coil that will not work good with low delay

[Jose]

"Remove or open collector T2 leg 5 of 4538"

Why?

Hello szucs_g
This circuit, T2, 4538, acts by increasing the delay time to avoid overload, with large objects near the coil.
For the detection of small objects with coils of 28 cm, you can override this, for a smooth adjustment of the delay control.
Regards

[demone]

12 volt output in coil

Hi everyone.Recently i managed to "construct" the delta pulse.
My circuit works great.All the 4538's 062 etc working BUT i got 12 volt output there where i want to put my coil.I get 12V dc voltage.When i connect my coil(3.5R) i get a high current.As a result my Irf740 getting hot and i have to pull off the dc power!If i leave the coil for 4-5 sec my 740 is no more usefull;has been destroyed.
Enyone that could help?
Thank you!

[ossamaussama]

Hi everyone.Recently i managed to "construct" the delta pulse.
My circuit works great.All the 4538's 062 etc working BUT i got 12 volt output there where i want to put my coil.I get 12V dc voltage.When i connect my coil(3.5R) i get a high current.As a result my Irf740 getting hot and i have to pull off the dc power!If i leave the coil for 4-5 sec my 740 is no more usefull;has been destroyed.
Enyone that could help?
Thank you!

this problem occur with many people


i can tell you the following


1-D9 AND D8 check if they good and not shorted

2- check the E- without connecting IRF740

it should be -10.6 with respect to E+

if you dont have oscilloscope as me

you can use buzzer to here some click sound at LM556 output

3- never start the machine with high power tx pot p3


4- low turns may make this problem

you need (2-4 ohms coil with 25 turns for small one and 16 or less for large one)


if all above was ok

connect the IRF740 or better replace it

dont connect the coil and remove R6 temporary

check with buzzer at the IRF740 GATE
is there any sound




*- very important note


c30 and c31 connected always to the battery then connected to the machine by switch
use c7 200 uf as this will speed up the generation of E-



REGARDS

[demone]

this problem occur with many people


i can tell you the following


1-D9 AND D8 check if they good and not shorted

2- check the E- without connecting IRF740

it should be -10.6 with respect to E+

if you dont have oscilloscope as me

you can use buzzer to here some click sound at LM556 output

3- never start the machine with high power tx pot p3


4- low turns may make this problem

you need (2-4 ohms coil with 25 turns for small one and 16 or less for large one)


if all above was ok

connect the IRF740 or better replace it

dont connect the coil and remove R6 temporary

check with buzzer at the IRF740 GATE
is there any sound




*- very important note


c30 and c31 connected always to the battery then connected to the machine by switch
use c7 200 uf as this will speed up the generation of E-



REGARDS

Hi ossamaussama and thank you for the fast respond.
1-D8 and D9 both of them have a voltage between 0-0,03.They do not seem to conduct.
I disconected the IRF740 and checked the voltage bt it was -11.3 and not -10.6.
The has alrady worked on another delta pulse and it was just fine.

[ossamaussama]

Hi ossamaussama and thank you for the fast respond.
1-D8 and D9 both of them have a voltage between 0-0,03.They do not seem to conduct.
I disconected the IRF740 and checked the voltage bt it was -11.3 and not -10.6.
The has alrady worked on another delta pulse and it was just fine.

********


do the following

disconnected D8 AND D9

check them with DIGITAL multimeter



E- should be -10.6

with respect to E+

it seem you have problems

IN THIS PART


IT happen to me in past

the reason was defective D8
check that


some time inverse direction of bc546 make problem

and kill the pulse

check T2 and T3

it is not like 2n3904 and 2n3906 in directions




take my advice and change D8 and D9

[porkluvr]

Hi everyone.Recently i managed to "construct" the delta pulse.
My circuit works great.All the 4538's 062 etc working BUT i got 12 volt output there where i want to put my coil.I get 12V dc voltage.When i connect my coil(3.5R) i get a high current.As a result my Irf740 getting hot and i have to pull off the dc power!If i leave the coil for 4-5 sec my 740 is no more usefull;has been destroyed.
Enyone that could help?
Thank you!

-If- you can tell your 4538 are working that would probably mean that you have pulses coming from the 556 pin-9. In that case, you should also be able to see input pulses to the IRF740. Maybe you have IRF740 reversed?

[Ajay0707]

PCB diagram of DP

Hello Everyone,

I would also like to build the Delta Pulse could anyone be able to share the most recent PCB diagram. I want to etch my own PCB by toner transfer method , so the sizes of the printout will help me a lot.

Thanks In advance.

Ajay0707

[Ajay0707]

PCB diagram of DP

Dear Gurus,

I read most of the pages of this thread and in each thread people have talked about modifications to the device. So that made me ask for the most recent PCB diagram and its sizes in centi meters of Inches as I have to etch my own PCB. I have downloaded the PCB diagram from falezyab ( parsiblog) but it has no PCB dimentions mentioned in it.

Thanks in advance for your help..

-Ajay0707

[pigeon]

Hello Mehdi
Change C1 to (22 nf) by 1.5 nf
Change R1 to (470k) by 68k.
Set PR1
Be careful with power.
regards
Jose

HI JOSE

15NF OR 1.5NF

THANK YOU

[Jose]

HI JOSE

15NF OR 1.5NF

THANK YOU

Sorry for the mistake, is 15 nf
Jose

[detecto]

Hello Everyone,

I would also like to build the Delta Pulse could anyone be able to share the most recent PCB diagram. I want to etch my own PCB by toner transfer method , so the sizes of the printout will help me a lot.

Thanks In advance.

Ajay0707

If i remember the dimensions of one sided pcb is 17,5 X 9 (or 9,5cm)
Regards

[kt315]

Dear Gurus,

I read most of the pages of this thread and in each thread people have talked about modifications to the device. So that made me ask for the most recent PCB diagram and its sizes in centi meters of Inches as I have to etch my own PCB. I have downloaded the PCB diagram from falezyab ( parsiblog) but it has no PCB dimentions mentioned in it.

Thanks in advance for your help..

-Ajay0707

what PCB you mean? there are amount of PCB diagrams on DP... have you Sprint Layout 5 installed on your computer?

[bernte_one]

last little steps

hello
i have finished delta pulse
but little question before first try:
do i have to set wire bridge between
point A and A (red circle)
and B and B(pink circle)

can i let micro amperemeter off board (red marked)
and let holes open ore do i have to set wire bridge here too
( i think i can let it off board and set no wire bridge)


thx

[bernte_one]

ok
answered by myself
points A-A are testing points for preset
and B-B for delay
i think micro amperemeter not needed

and point named tune at IC4066 pin13and 14 is for reset (push button?)

i used istead of a green and a red led two strong clear white led
is that a problem maybe of other voltage for green and red (want to colour them with edding)

i have a continuing sound when powered on
what is wrong i can´t switch it off (when turning potis and trimmers)
coil ist 2,7 ohm 30cm diameter

should work for first test or not?

regards