Delta Pulse

[kt315]

Also, I see on your schematic STTH1210D diode, can I use MBR1035 instead?

Schottky is not able work in circuits where more than 50V. guys, learn the blsht electronics, more books around you are able get in global net.
do not ask me primitive questions. here is forum for metal detectors, not for absolute beginners.

you need be looking for more than 1000-1200v diode.

SCHOTTKY IS LOW VOLTAGE DIODE. its the rule!

[rankx0]

Images Tr3min.png and Tr3max.png are made with 830mH coil. Is it too much inductance? Another coil I have is 280mH.

[rankx0]

Also, I see on your schematic STTH1210D diode, can I use MBR1035 instead?

[rankx0]

Considering last images (Tr3min280uHcoil.png and Tr3max280uHcoil.png), and given ranges 100-700us, values are:
R4 3.91k (measured)
C3 22n (I can't measure capacitors, so I give printed value)
DEPTH 25k

Previous measures (range 60-350us):
R4 5.59k (measured)
C3 10n
DEPTH 25k

[kt315]

write measured values of
r4 c3 and pot DEPTH.

[rankx0]

And with another coil (280uH), I have those values - almost perfect.

[rankx0]

Now I tried to change R5 and C3 as above, and this is what I get with Depth on minimum:


This is what I get with Depth on maximum:

[rankx0]

I have tested Tr3 and I have 60-350us range when I turn Depth pot from min to max. What do I have to change to get 100-500 us here? I tried to simulate those two vibrators, and in simulator R5 must be set to 4k2 and C3 to 22n to achieve 100-500us range with 20k Depth potentiometer. Should I change them that way, or there is another thing to do?

[kt315]

Impulse width at Tr4 is ~45uS. The same widht is at Tr5.

good

[kt315]

OK, I have changed 680k to 820k and now I can adjust period to 10mS using PR1. I must get second probe, so I can compare test points, so I will post when I do it. Do you have any clue what is going on, why it doesn't react to coil? This is graphic for my Tr3, period is 10mS, but impulse length is 60uS.

[ATTACH]38572[/ATTACH]

When I rotate Depth / Noise potentiometer, I can set it to 100uS. Is it OK?

not ok. you have to get approx 100-500 us range.

[rankx0]

Impulse width at Tr4 is ~45uS. The same widht is at Tr5.

[rankx0]

OK, I have changed 680k to 820k and now I can adjust period to 10mS using PR1. I must get second probe, so I can compare test points, so I will post when I do it. Do you have any clue what is going on, why it doesn't react to coil? This is graphic for my Tr3, period is 10mS, but impulse length is 60uS.



When I rotate Depth / Noise potentiometer, I can set it to 100uS. Is it OK?

[kt315]

for 100 PPS/Hz you must get 10ms in TR2, period. increase R1 if you can not set the value by PR1. pulse length is ok.

[rankx0]

I am in Serbia. This is the "on" impulse length, approx. 75-80uS, and distance between them is 9ms when I turn PR1 to minimum. When I turn it to maximum, I have 6.4mS.

[kt315]

75us long? set PPS - for USA - 120Hz. what your country?