Delta Pulse

[mehdi]

Hi friends
anyone know how i can increase strobe impulse to 1000 us in delta pulse?

best regard

[sevar12]

Yes i see thenk you very much

[Tepco]

No way to work whit 5534 (or anything similar)

[sevar12]

hello every one
now i see that ne5534 not be the same as lm 357 may be this is a problem to dp not work

[Tepco]

U4 is input amp, U6B acts like integrator, (R19/C16 time constant) auto-zeroing U4 when U9D is closed. U4 (LF 357) is somewhat specific chip, whit common mode range accepting +V, and about 100mV above (can not be replaced whit 5534 or some other typical PI opamp), circuit will work this way. Power supply distribution on XR71 in complete nightmare, but works, no matter how strange it looks, figure out what is GND reference for what part of ckt.

[DOOLEY]

hello , pics below.

[DOOLEY]

hello all ,
been looking at the delta pulse and xr71 schematic , and i'm a little puzzled , hope somone can explain.

below is two extracted pics from dp / xr71 ,

firstly , the two op-amp's u4 and u6b , look to be feeding back / in a feed back loop , why is this , what is the purpose , checked on the net and can't find any examples that have this configuration to get an explination of what's going on.

my first thought was a type of automatic gain adjustment or automatic leveling of signal , the nearest thing i found that looked close was a high pass filter.

next question , i notice that the first op-amp , u4 has the same feed as the search coil , 12V , how can this work , as far as i was aware , the first op-amp requires a hight supply than the singnal which its dealing with , in this case it's 12.7V ish down to 12V , yet u4 appears to only have a 12V supply , ( +E) same as the search coil.

and lastly in the power supply pic , u6a , looks to delivering a regulated , but low current 5.3V supply to a reil noted with the ground symbol , been trying to work out a voltage scale for this detector , (-12V) = 0v
(-E)=1.4v
earth=5.3v
(+E)=12v
can't see anything higher than 12v so still puzzled as to how u4 can work.

i could be blind , and haven't seen it yet , but this is doing my head in , please help.

pics on next post , forgot to add.

[fidamohd82]

hi
and what do you advise about the coil

regard

[homefire]

hi to all
i made the delta pulse it is working but with no depth just 3 or 4 cm
what will i do

If you in fact built by the schematic and used the correct parts, how did you build the coil?

[fidamohd82]

hi to all
i made the delta pulse it is working but with no depth just 3 or 4 cm
what will i do

[boeNorway]

hmm

whats the price for all the components for the Delta Pulse
and was there someone here that sold the 2 side pcb if i asked nice


ore is there some one here ho is ready to bild another metall detector and dont nead
the Delta Pulse pcb and components


Sorry for being bad at spelling but im made this way .


Best Regards to all of you .
this Thread was werry intresting .

[raff33]

Hello Raff33
Set the multimeter in frequency counter function
Punta black on - E, red lead on pin 9 of IC 556.
It can perform with the coil disconnected.
Regards
Jose

Hi jose,
now i inderstand ......
- black lead on -E(pin7 of LM556).
- red lead on (pin 9 of LM556).
many thanks
REGARDS

[Jose]

Hello Raff33
Set the multimeter in frequency counter function
Punta black on - E, red lead on pin 9 of IC 556.
It can perform with the coil disconnected.
Regards
Jose

[raff33]

Hi,
please can anyone gide me how to get my delta pulse frequencey with my digital multimeter ?
- where connect black and red leads ?
- should i mesure frequency without connecting coil ?
Regards

[Jose]

Thank you for clarifying the concepts kt315.
Jose