Replies to Minipulse Plus

[6666]

Since you are so fast, you could try this time base as a GB for minipulse too. It will take you 20 minutes at most
Ask me for details if you are interested.

Davor have you built your time base ? how does the 4017 cycle through with the clock connected to the reset ?

[ivconic]

This appears to be the same problem I mentioned with the missing connection on the LT1054. It's probably related to the 7660.
My version doesn't have the same issue, even with a Cola can sat directly on the coil.

I can check that when 1054 comes to my hands, soon.
What are the chances we to include motion/nonmotion mode switch?

[ivconic]

BTW, try LF353 instead of TL062 in integrator

Now he tells me that!
I soldered ic's directly without sockets, except 7660 which is on socket.
Ok, no problem, i will destroy 062 and put socket there too.

[ivconic]

Since you are so fast, you could try this time base as a GB for minipulse too. It will take you 20 minutes at most
Ask me for details if you are interested.

I am so missing schematic done in ExpressSCH!
"Alive" schematic with "movable" components where we can add your ideas faster and clearer.
Don't mind me if i do that first, right?
First i will transfer schematic in ExpressSCH and later we will talk further. I'll try to do that tomorrow.

[Qiaozhi]

There is large increase in frequency alright, but at strong detection signals there is obvious decrease in audio amplitude.
Listen carefully on video, there is a moment when you can hear audio amplitude decrease down to some level and that's the same moment when detection signal is very strong.
And funny; loudest audio you may hear on video is when moving target is distant and producing not so strong detection signal.
Next time i'll try to shoot better video with targets and coil.

This appears to be the same problem I mentioned with the missing connection on the LT1054. It's probably related to the 7660.
My version doesn't have the same issue, even with a Cola can sat directly on the coil.

[Qiaozhi]

I am fast because i don't read manuals!

More haste less speed.

[Davor]

BTW, try LF353 instead of TL062 in integrator

[Davor]

Since you are so fast, you could try this time base as a GB for minipulse too. It will take you 20 minutes at most
Ask me for details if you are interested.

[ivconic]

I knew it! [/FONT]


On the REV-B board there was a connection missing between U2 pin 5 and U2 Pin 3. This caused the audio volume to decrease when a large target was close to the coil. I'm not sure whether I'm hearing the same thing in your video, but since you're using a 7660 this may not be useful information.

There should be a small increase in amplitude, as well as a large increase in frequency, as the target gets closer to the coil.

[/FONT]

There is large increase in frequency alright, but at strong detection signals there is obvious decrease in audio amplitude.
Listen carefully on video, there is a moment when you can hear audio amplitude decrease down to some level and that's the same moment when detection signal is very strong.
And funny; loudest audio you may hear on video is when moving target is distant and producing not so strong detection signal.
Next time i'll try to shoot better video with targets and coil.

[ivconic]

I'm impressed!!!
You received your PCB only yesterday, and your minipulse already works. Do you sleep at all?

I am fast because i don't read manuals!

[Qiaozhi]

"...I suspect you've been a bad boy and populated the whole board before testing..."

But of course i did... you know me!

I knew it!

Was it just me or i do hear significant audio amplitude decrease when detection signal increasing? I don't like that. I expect audio amplitude to increase too.

On the REV-B board there was a connection missing between U2 pin 5 and U2 Pin 3. This caused the audio volume to decrease when a large target was close to the coil. I'm not sure whether I'm hearing the same thing in your video, but since you're using a 7660 this may not be useful information.

There should be a small increase in amplitude, as well as a large increase in frequency, as the target gets closer to the coil.

[Davor]

I'm impressed!!!
You received your PCB only yesterday, and your minipulse already works. Do you sleep at all?

[ivconic]

Forgot to mention; this is with 7660, don't have 1054 yet, intend to obtain it too, soon.
Also this is without Cxx sync cap...

[ivconic]

[ivconic]

Did you carefully follow the instructions in the Build Document? ->

---------------------------------------------------------------------------------------------------------------------
If you go through the following steps carefully, and in order, you will have a greater chance of
ending up with a detector that actually works. Do not proceed to the next step until you have solved
any problems encountered in the current step. If you get stuck at any stage during the build, then
seek help in the Geotech forums before moving on. Do not simply populate the whole board;
discover it doesn't work (which will be the most likely result) and then post in the forums: “I've
built the Minipulse Plus, and it's not working. What's wrong?”, as you will receive little sympathy
from other Geotech members.
To reiterate:
Please follow the instructions step-by-step.
---------------------------------------------------------------------------------------------------------------------

I suspect you've been a bad boy and populated the whole board before testing. If so, I would suggest reading each step now, and follow the test procedure. This should help to isolate the problem.

Regarding the threshold. It has been mentioned previously that the sensitivity is set to maximum, which means it does move from a position of slow ticking to a faster tick quite rapidly. If you want to adjust this, then you can try increasing the value of R35. Have a look at the original MiniPulse schematic. There was an internal trimmer between the opamp and R35, and a fixed resistor that's normally connected to -5V when the battery warning circuit is inactive. This trimmer allows adjustment of the threshold sensitivity

The "chatty" behaviour will only become evident if you have the threshold set to something higher than a very slow ticking. However, you won't miss any targets, as the tone increases very rapidly.

"...I suspect you've been a bad boy and populated the whole board before testing..."

But of course i did... you know me!
Give me a break George! It has nothing to do with fact that i did it unlike you suggested!
(manuals are for woosies - not for tough guys like i am!)
I just founded what was the problem!
Arghhhhhhh!
I haven't connected coil properly! Can you believe it!?
You and your "dozen" pins for coil on pcb!!!
Actually; coil was connected between tx and rx pins only! Arghhhhhhhhhh!
It's your guilt! You and your 2x3 pins!

Ok, but before i realized that coil was not connected properly; i suspected those poor J113, so i destroyed them both when tried to remove them from pcb.
Now i don't have J113 no more...
But i do have my beloved J107 ! Ha!
So; J107's are on their places, coil is connected properly...and it is working now!
After half hour playing with it i collected some conclusions:
1) 8 ohm speaker sucks, 100 ohms speaker RULEZ!
2) Automatic Treshold is not making me very happy, i would like to have option to choose between. I prefer nonmotion mode.
3) Was it just me or i do hear significant audio amplitude decrease when detection signal increasing? I don't like that. I expect audio amplitude to increase too.
...
Ok enough for now. I recordered very short video focusing only on audio behavior.
Right now i will upload it on Youtube and later share here.
Cheers!