Step 7 question

[omr255]

Hi!

I am on step 7 of the kit (so far works) and I am not sure whether to continue or not.
R14 does not seem to change at all apart from a slight change in the faint hum coming off the coil.
Could I have possible got the wrong pot in place (20k in 100k)?
The top of the pot in r14 has 306E w 203.

here is a picture of the board.
http://i.imgur.com/xK8P1Bu.jpg
Anything wrong?

[omr255]

For some reason a different picture is showing even though I uploaded the newer one.

Hi!

I am on step 7 of the kit (so far works) and I am not sure whether to continue or not.
R14 does not seem to change at all apart from a slight change in the faint hum coming off the coil.
Could I have possible got the wrong pot in place (20k in 100k)?
The top of the pot in r14 has 306E w 203.

here is a picture of the board.

Anything wrong?

Edit* Fixed.

[Qiaozhi]

Hi!

I am on step 7 of the kit (so far works) and I am not sure whether to continue or not.
R14 does not seem to change at all apart from a slight change in the faint hum coming off the coil.
Could I have possible got the wrong pot in place (20k in 100k)?
The top of the pot in r14 has 306E w 203.

here is a picture of the board.
http://i.imgur.com/xK8P1Bu.jpg
Anything wrong?

Have you checked this ?> "Make sure you attach your coil and short pin2 of PL2 to either pin 1 or pin 3 (before adjusting R14) otherwise the
voltage will not change."

[chevesne]

warning, it seems one of the pins 1 or 3 is not connected to ground on the pcb.

[Qiaozhi]

warning, it seems one of the pins 1 or 3 is not connected to ground on the pcb.

It's strange that no-one has noticed this before. The lower pin of P2 is unconnected. I will add that to the "Updates and Corrections" on the Project Details page.

[omr255]

Have you checked this ?> "Make sure you attach your coil and short pin2 of PL2 to either pin 1 or pin 3 (before adjusting R14) otherwise the
voltage will not change."

Yes I have.
I get a reading pf -2.13 volts on u7 pin 1 when i short pl2 pin 2 and 3 but nothing when I short it with pin 1.
Also there is no voltage change on u7 pin 1 when a metal object gets close.

[homefire]

Have you checked this ?> "Make sure you attach your coil and short pin2 of PL2 to either pin 1 or pin 3 (before adjusting R14) otherwise the
voltage will not change."

What is the PL2 ?

[Qiaozhi]

Yes I have.
I get a reading pf -2.13 volts on u7 pin 1 when i short pl2 pin 2 and 3 but nothing when I short it with pin 1.
Also there is no voltage change on u7 pin 1 when a metal object gets close.

Yes, PL2 pin 2 needs to be connected to pin1 to run the test. See post #5.
Did all the previous tests pass ok, and do you have an oscilloscope?

[Qiaozhi]

What is the PL2 ?

PL2 is the 3-pin connector for the sample delay pot.

[omr255]

Yes, PL2 pin 2 needs to be connected to pin1 to run the test. See post #5.
Did all the previous tests pass ok, and do you have an oscilloscope?

Yes all previous tests have passed with success. I do not happen to have an osscilloscope. The IRF does get a bit hot.

[omr255]

Any diagnosis?

[Qiaozhi]

Yes all previous tests have passed with success. I do not happen to have an osscilloscope. The IRF does get a bit hot.

The MOSFET should not be getting hot. Are you sure that the coil is ok, and the TX oscillator is working?

[chevesne]

And what answers do you bring to this tread ?

http://www.geotech1.com/forums/showt...rracuda-HELP!!

[omr255]

The MOSFET should not be getting hot. Are you sure that the coil is ok, and the TX oscillator is working?

The speaker makes a low tone sound when connected to u4 pin 4 and the coil is 20 turns of .5mm copper wire of around 20cm diameter.

[omr255]

The MOSFET should not be getting hot. Are you sure that the coil is ok, and the TX oscillator is working?

The coil is exactly 27cm in diameter.