For sale bare boards for Delta Pulse/Sniffer XR-71

[kt315]

To put it simply, turning up the depth pot, increases the pulse width of the TX, which increases the "ON" time of the MOSFET. This means that the MOSFET is now going to dissipate more power (heat), which is why you have to put it on a heatsink. Otherwise you can damage the MOSFET.

there is a specific limitation of the voltage amplitude on peak. MOSFET is working like Zener diode if the peak-to-peak
amplitude is above 400V. whole cutted top of the delta pulse, his energy, certainly goes in the heat.
so 100-150us PULSE WIDTH is still within the permissible, 'safe', no the limitation and heatsink is not needed, but on 400us and more we get the excess heat.

[kt315]

thank you George for support in this hardest deal. your understanding of the situation is perfect, like always.
really this guy loves to overload me by blank empty requests (he loves to write doubles in PM too).
certainly i am on nerve... my bio-energy stock is long ago in state red LED 'ON'. i have to sound like an elephant long away.
this guy with zero level of a lamer went whole stages to the finish and on every one i said myself just WOW. he got a result - reaction on metal.
that is absolutely rare thing we see here in geotech. THE record. while i still waited the Magic Smoke... on every his step...
that occured. now he asks help... those people set sockets on every chipo... they so love to set the sockets...
but for what ? they do not understand. 'because all people set the sockets and i will do same' - their main principle in their life.

all the best

[chuubaba]

I have velostat sheet and bare conductive paint. Will these work for shielding?

[TufaN]

hello this DP pcb s really nice and stable works. Integrating quality electronic components, transistor, capacitor. they all have to use good quality. and the box assembly should be very good. Absolutely graphite shield and beautiful workmanship required. my DP is the same pcb ike board. 50cm coil 20x30 copper pcb making detection of 2.45 cm. 1x1 coil approach 3.15 cm depth. these are not air tests. targets buried under the ground. I'm sorry for my bad english

[Qiaozhi]

MOSFET changed but board is not waking up.

Chuubaba ... with all due respect, I just do not understand what you are hoping to achieve here.
Such a barrage of questions!

My guess is that you want to make a metal detector to find some deeply buried treasure. However, your knowledge of electronics is clearly severely limited. I would suggest that you put the Delta Pulse on one side and get yourself a prototyping board like this ->
plus a selection of resistors, capacitors, inductors, bjts, mosfets and opamps. Then, with a beginners book on electronics, use the prototyping board to understand practically what all these components actually do. If you have an oscilloscope, then also learn all of its functions and use it to increase your understanding. Once you've got to grip with all the basics, study the Delta Pulse schematic. A copy of ITMD would also help considerably. Inside the METAL DETECTOR - Second Edition - Published 2015
You cannot simply swap out components on a random basis when trying to fault find a non-working circuit. There is no substitute for knowing what you're doing. If you don't have the patience to walk before you attempt to run, then electronics as a hobby is probably not a good idea. You would be better off saving a lot of time and money, and buying a working commercial detector.

This is just my observation, so you can take it or leave it. But I hope you take notice, as poor KT315 is probably going to explode with frustration.

[chuubaba]

MOSFET changed but board is not waking up.

[chuubaba]

Dbanner you perfectly predicted a breakdown.

[chuubaba]

So i change the MOSFET or the power supply transistors?

[kt315]

in min position mosfet is cold, yes. in max position mosfet is hottie like your next door beaty
alien wife who is absolutely unaccessable for you.
do pause experimenter. give the smoke go out.

[chuubaba]

Oh dear lord...have mercy!!!!
Chuuuuuuuuu........babababa!!!!!Boom!
I see some folks like to learn electronics the hard way.
I have a feeling the magic smoke is coming next. I get popcorn and cookies ready.

I didn't install the heat sink because MOSFET was always ice cold.
I only touched up the R52 soldering prior to powering it on. BTW no smoke was seen.

[chuubaba]

I supply power after installing the block connectors and now the board is not working at all.

[dbanner]

To put it simply, turning up the depth pot, increases the pulse width of the TX, which increases the "ON" time of the MOSFET. This means that the MOSFET is now going to dissipate more power (heat), which is why you have to put it on a heatsink. Otherwise you can damage the MOSFET.

[dbanner]

Oh dear lord...have mercy!!!!
Chuuuuuuuuu........babababa!!!!!Boom!
I see some folks like to learn electronics the hard way.
I have a feeling the magic smoke is coming next. I get popcorn and cookies ready.

[kt315]

did i write anywhere to set the pot PULSE WIDTH/depth in full clock position? you do just you want do.
yes, your power supply is in overload state now, no good power, the bad source, LED RED is lighten because low voltage
and the cause is me? you did not set MOSFET on heat sink, you did refuse to buy HV diode,
the cause is me?
it seems you want to drive your car without a fuel. advanced fuel-free technology?

[chuubaba]

you do what you want despite my suggestions. next you maybe do wooden box. i do not know.

[ATTACH]48126[/ATTACH]

I have joined the connectors.
Now my board has two problems
1 THE RED LED IS ON AND SOUND IS FUNNY IF DEPTH POT IS TURNED TO NEAR FULL (DIRECTION OF CLOCK)
2. IT HAS SMALL DETECTION DEPTH
HOW TO SOLVE THIS ?