Levitation base assembly...discussion

[Zedsquared]

HI Tony,
you need to circle R19 on the second article on lev base PCB assembly. If it gets missed out then it looks like the power coil doesn't get driven.

Cheers,
Robin.

[leedawg]

So looking for some feedback on the levitating base part of the build. I have finished the PCB up to the point where testing is required. SO the mag coil PCB has been mated to the control PCB at the solder pads as stated. I had a few questions about the touch switch. Seems as though in the pictures of board the touch switch is way over on the other side of the board near the power plug just to the left of the yellow tank capacitors. The directions in the PCB assembly clearly show the three points to solder the leads of the touch switch to right over the IC socket where the pic controller is. That is where I put mine and when I powered it up with the current volt meter I get a steady beeping noise that goes up in tone 3 steps and stays at the high pitch tone steadily till I cut the power. I also notice the green LEDS come on then go off. And the red led on the touch switch stays on constantly from power up. So I figured maybe something is wrong with my red touch switch so I removed it from the board and powered up again and still get the same symptoms this time the switch is not even on the board. Perhaps bad touch switch anybody else run into this. I also noted some of the resistor color codes were different in the build description from the ones supplied in the kit. A couple of photos depicting where the touch switch goes would be nice to clarify.

Lee

[leedawg]

Well I successfully figured out what my problem was with the touch sensor. The pin outs on the sensor are not in the order of Ground VCC the I/O the I/O pin is in the middle and I had reversed the VCC and IO pins. After this correction everything function just as it was described in the directions. I then successfully hovered the magnet on the thing all was looking great and when I went to take the magnet off it dove to the right and that is when things went south. I have a solid red light on the touch sensor and no tone is heard. I powered the unit off and then powered it back up the red light on the touch sensor went away and it sees my touch indicated by the red light coming on however no tone is heard from the speakers now. I also noted there is no IR emission from the LED's I made a video demonstrating this if anybody cares to look at it.

https://youtu.be/e6b7GMLcBDU

I think i am going to start on the last PCB and wait to hear a response on the levitation base. My hunch is somehow the PIC controller got wiped or actually damaged. But I could be wrong. Its as if the board acts like there is no pic controller installed when we were doing the initial current testing.

Lee

[Skyraider]

Hi Tony,
just to mention a little error in PCB assembly:
I put LS1 as described (+ point to the Top right) and there was no sound. This is because it is misoriented. I inverted it and now it works fine.

The speaker LS1 is shown on the wrong side in the picture : The + should point to the Bottom left and not to the Top right as mentioned. (Top right pin goes to the 2N7000 and that is the negative pole).

[Skyraider]

Well I successfully figured out what my problem was with the touch sensor. The pin outs on the sensor are not in the order of Ground VCC the I/O the I/O pin is in the middle and I had reversed the VCC and IO pins. After this correction everything function just as it was described in the directions. I then successfully hovered the magnet on the thing all was looking great and when I went to take the magnet off it dove to the right and that is when things went south. I have a solid red light on the touch sensor and no tone is heard. I powered the unit off and then powered it back up the red light on the touch sensor went away and it sees my touch indicated by the red light coming on however no tone is heard from the speakers now. I also noted there is no IR emission from the LED's I made a video demonstrating this if anybody cares to look at it.

https://youtu.be/e6b7GMLcBDU

I think i am going to start on the last PCB and wait to hear a response on the levitation base. My hunch is somehow the PIC controller got wiped or actually damaged. But I could be wrong. Its as if the board acts like there is no pic controller installed when we were doing the initial current testing.

Lee

Hello, I had some similar behaviour: When hovering the magnet, sometimes, the capacitive sensor showed a solid red light and the tone went increasing. I had to power off and on again to stop that. In my case, the PIC always restarted correctly. The sensor was placed above the PIC as described in the instructions.
I decided to place the sensor on the opposite side (near the yellow capacitors) as shown in the Case assembly section.

Since then, it seems that the issue was solved... I think that the sensor was not functionning well due to electromagnetics interferences...
For that, I connected to Vcc using the upper end or R9 (be careful not to unsolder the red wire that is on the same point on the other side of the PCB). I connected the signal using the lower end of R9 and I connected the GND using the right leg of C8.
For the signal (lower leg of R9), you will have to connect a wire between the left leg of C11 (you can remove C11, it is unused) and the collector of T1 (this will bring the signal to the PIC pin4). see details in attached document...

From what i saw in your video, and if you say that there is no IR signal, it seems that your PIC is dead...

Hope that helps

[leedawg]

Well I successfully figured out what my problem was with the touch sensor. The pin outs on the sensor are not in the order of Ground VCC the I/O the I/O pin is in the middle and I had reversed the VCC and IO pins. After this correction everything function just as it was described in the directions. I then successfully hovered the magnet on the thing all was looking great and when I went to take the magnet off it dove to the right and that is when things went south. I have a solid red light on the touch sensor and no tone is heard. I powered the unit off and then powered it back up the red light on the touch sensor went away and it sees my touch indicated by the red light coming on however no tone is heard from the speakers now. I also noted there is no IR emission from the LED's I made a video demonstrating this if anybody cares to look at it.

https://youtu.be/e6b7GMLcBDU

I think i am going to start on the last PCB and wait to hear a response on the levitation base. My hunch is somehow the PIC controller got wiped or actually damaged. But I could be wrong. Its as if the board acts like there is no pic controller installed when we were doing the initial current testing.

Lee

Hello, I had some similar behaviour: When hovering the magnet, sometimes, the capacitive sensor showed a solid red light and the tone went increasing. I had to power off and on again to stop that. In my case, the PIC always restarted correctly. The sensor was placed above the PIC as described in the instructions.
I decided to place the sensor on the opposite side (near the yellow capacitors) as shown in the Case assembly section.

Since then, it seems that the issue was solved... I think that the sensor was not functionning well due to electromagnetics interferences...
For that, I connected to Vcc using the upper end or R9 (be careful not to unsolder the red wire that is on the same point on the other side of the PCB). I connected the signal using the lower end of R9 and I connected the GND using the right leg of C8.
For the signal (lower leg of R9), you will have to connect a wire between the left leg of C11 (you can remove C11, it is unused) and the collector of T1 (this will bring the signal to the PIC pin4). see details in attached document...

From what i saw in your video, and if you say that there is no IR signal, it seems that your PIC is dead...

Hope that helps

You were correct on the PIC however it turned out to be a problem with the oscillator. THe crystal had some problem with it replaced the crystal and it fired right up again so got that solved. I still have the very annoying problem of the touch sensor activating itself for whatever reason and then staying stuck on until as you said it is power cycled. I have placed a capacitor across the leads as tony had recommended (I used and electrolytic cap) still same results. It even overnight triggered itself somehow after the base had been floating for several hours.

Tony do you have any suggestions on this have you not seen this as a problem with any of the units you have built? Thanks again.

Lee

[Tony]

Connect a link across R13, shorting it out. I've just finished building 70 bases and this should work.

[Skyraider]

Hello Tony,
I have exactly the same behaviour as Lee described: after several hours, sometimes, the touch sensor triggered by itself...
When you suggested to connect a link across R13 (shorting it out), do you mean that it will solve the touch sensor issue?
If I understand well, R13 is for the overcurrent detection (with R14 in //).
Did you find why the current in R13 was able to trigger the Touch Sensor? I don't understand the correlation
Thank you in advance if you can clarify that.
Best regards
Emmanuel

[Tony]

Yes it will. The current sensing is on the ground side. The electromagnets when stabilising draw a considerable amount of current, 1-2 amps usually, for a short time. If the touch switch attempts to recalibrate at that point the supply voltage relative to ground will be slightly higher, it'll then drop causing the switch to trigger. The overcurrent protection wasn't needed in the end as the undervoltage protection shuts it down.

[Skyraider]

Thank you for this clear explanaition. I proceed to the modification and it seems to work very well (it is only 10mn since I powered it again, but I already saw that there is no more touch sensor self-trigerred when placing the floating unit.)
In addition to that ,placing a wire in place of R13 is better for the electronics and the PIC as it will remove the "floating" 0V and so provide a more stable 5V (as the 5V regulator is coming from the levitating unit).
Thank you again !