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GB controls are functional and SAT value added to APP. 
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Hi Moodz I have a query regarding R20. At one point this went to 10Mohm but is now 10k. The reason for my question is that the TX signal at the coil does not have any flyback pulse and looks almost square wave however if I remove U4 the classic signal appears leading me to believe Q2 is permenantly off. Any ideas?
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If your flyback is missing it means something is blown ... eg Q2 or the input to the opamp U2. Does the opamp feel warm ? This can happen if too much voltage is applied or a probe in the wrong place.Originally posted by Gunghouk View Post
R20 value can vary according to the firmware .... The flyback is proportional to the ( total ) X ie reactive load the collapsing magnetic field sees.
Kind of hard to explain in a few words but basically R20 controls the X or reactive recovery time which changes with reactive loads eg ferrites near the coil etc.
10K is a faster recovery ... 10 meg is a slower recovery.Comment
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Here is the Android APP and the Corresponding Firmware. ( THIS REQUIRES A HC-05 Bluetooth Module ) and the latest Schematic.
You dont need the rotary encoder or LCD.
Note that the Android app is unsigned. If you load it into your phone and it drains your bank account dont blame me.
Use an old phone ( not too old though )
I tested on first generation PIXEL and OPPO ... worked OK.
Android 10 and above ??
This is a work in progress .. your mileage may vary.
MAGPI008_2024_04_23_V1.5_DEVEL.X.production.zip
app-release-unsigned.zipComment
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Thanks for that. I suspect the op-amp as the behavior changes with U4 in or out so the mosfet is changing state. I don't have another LM6171 will a NE5534 do temporarily?Comment
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"How to use the App" video is here
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The other possibility is that D1 has gone short circuit.Originally posted by Gunghouk View Post
Unfortunatey no because the inbuilt "protective diodes" across the inputs of the ne5534 draw current and the chip will just get hot.
Also make sure the coil is attached when applying power ... ie dont attach the coil with power applied. Wont damage but will enter a lockup state.Comment
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You could try an ne5534 with a current limiting resistor in series to the inverting input eg 330 ohms or so.
Plug the NE5534 into the socket with the inverting input pin bent out then solder the resistor from the source of Q2 to the pin.
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Tried a simple amp prototype cct and looks like the LM6171 is shot. Off to the shops
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Buy 2
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The MAGPI is going hammer and tongs since moving to the android interface.
Now added sampling filter adjustment or ground smoothing.
Heres the video ...
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Invalid package, can't install on Android 14 Pixel 4a
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It seems that Google dont want you installing unsigned packages any more ... but it works if the android SDK loaded a version.Originally posted by Gunghouk View PostInvalid package, can't install on Android 14 Pixel 4a
Anyway here is a signed version and smoothing firmware. I will test this one by attempting to install from geotech.
You may have to change the security setting in your phone to allow installs that dont come from google play.
This is hot off the press so it may contain bugs ....
app-release.zip
MAGPI008_2024_04_23_V1.5_DEVEL.X.production.zip
EDIT : Downloaded it and installed OK.
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Thanks Moodz, quick initial test, no HC-05, pressing the indicator on the rh dial causes the app to stop/close. Rh indicator press shows toggle state message of the control.
I'll have the BT TX up and running later.
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That should be lh control indicator press shows toggle state
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