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May i try a TLC271???? it orks from 3V....
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So, bad chip, positively, 271 probably won't work.Comment
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I tried TLC271 and TL061. Both works as amplifiers with this voltage. Later i will try them with coils ... and i"ll inform you.Originally posted by Tepco View Post
RegardsComment
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Does this chip still works OK at your OpAmp Tester?Originally posted by Geo View Post
Possible replacement for MCP601 can be: EL8101, NCS2500, LMH6723, TSH110, MAX4452, LMH6642. Some of those in SMD and not every pin compatible. You can try, if you have one of those.Comment
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I have not any of your possible replacement ics....
But i tried the project with TLC271 and works ok. Without the capacitor 22nF i have an Rx signal of 370mv. With 22nf Rx=about 900mv but i have not the Rx error. I did not tried to set Rx at lower values manual.
Detecting distance is very good ... about 20cm for 1euro with sensitivity to 4, power at 4 and gain=1 With same settings it detect a one penny at 30cm about.....
What will happen with all near to max????
And now the bad news... detector is very astable. Always it has erratic signals. I disconnected the TLC271 and it had yet the same erratic signals. I disconnected the coils... but the same. I disconnected the Tx amplifier but again the same. I don't know what other to looking for!!!Pcb is clear, all pins of XMEGA seems to be soldering good.
Now i have problem....
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Problem remains...
btw... who is the rule of led1???? it flashes continuouslyComment
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LED1 can be omitted. It follow MCU digital processing. If your KROT-2 is now working unstable it is normal that this diode blinking continuously.Originally posted by Geo View PostProblem remains...
btw... who is the rule of led1???? it flashes continuously
Are you sure that your RX line Gain is set to 1?
Did you try to set "A" at Coil balance to 0 (by pressing + and - simultaneously?
Did you set your voltage settings to battery voltage used?
Try to put back C0 (22nF) and to change R10 value with 5k trimm-pot.Comment
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Originally posted by WM6 View Post
It is astable with D1, D2 and coils disconnected from pcb...
About "A" i don't remember.... i"ll give a looking
About voltage settings.... yes i played with it... i think that now it is at "50"
. Why... who is the rule of it???
Maybe a 5kgr hammer must give the solution : Lol:
RegardsComment
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"50"? Probably you mean 5.0V. Settings should be equal to battery power supply voltage. With it you tell MCU what voltage level to use in processing for correct results.Originally posted by Geo View PostAbout voltage settings.... yes i played with it... i think that now it is at "50". Why... who is the rule of it???
Regards
Hey, it is too early for hammer, if we have patience with our government to not test it with hammer, then this project deserve some more time too.Comment
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It is at number "54". With this number uc reads the battery as 4.8V. As bigger the number the lower indication...
First time that i tested it, had not erratic signals. I don't know what is happening. Maybe uC?????? but all routines at menu works ok....Comment
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Capacitors can be glue on the body next to the switch.Originally posted by Wiltran View PostComment
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Geo, do not whipping his head against the wall that does not help ..)Originally posted by Geo View PostI
Now i have problem....
1. What is your voltage DC 3-pin D2 , 44 and 40 pin D3?
2. What shows device in "Zero_adс"?
3. That shows the device in the "Сoil bl"?
All measurements were done at the disconnected coil !
4. How do you bridge the RХ connector and connector is connected to ground myself?
If you can show photo editing..
Not everyone is suitable operational amplifier A2! Especially not fit TLC271 and TL061 .. See the power supply voltage, frequency, and even such an option as Rail-to-Rail Output...Comment
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Originally posted by ANDREW K2 View Post
Hi Andrew.
1. I have many photos but i can't (for the moment) resize them so to attach here.
2. Voltage at pin3 D2 =1.63V, Pin 40 = 3.19V, pin 44 = 1.87V
3.At Zero adc device shows Urx 1542mv <249>
4. Coil bl shows 1461 mv, A=135 Φ or A=10α
5. Measurements were done with disconnected coils
6.Rx connected at C12 and gnd (bronchial of C7 R13 R14.). Also the shield of wires connected at the same place.
MCP601 was fault, i stay at a small city so i can't find so easy this chip... TLC271 was a solution for the tests.
Thank you for your reply
BTW... if i disconnect D2 and connect a capacitor 100n ... 1uF at pin44 of D3 the erratic signals remains so i suppose that problem is near to D3.Comment
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"Coil bl" A=0!
3. and 4. should show <50mV
Look at the oscilloscope pin_6 D2
What version of firmware you?Comment
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This is not the correct results ...Originally posted by Geo View Post
Make such manipulations:
1. Disconnect the sensor.
2. Set "balance coil" A = 0 (synchronous press "-" and "+")
3. Short-circuit terminals RX
4. Press "0 ADC" (value should be about 50 mV., Then the buttons "-" and "+" to adjust around 0 mV.) And forget about this mode.
5. Connect the sensor.
6. Find resonance TX. (Current should be about 80-100 mA.)
7. Balance sensor. (50-150 mV.'s A good indicator.)
8. Go look for coins.
If the unit emits a lot of sounds wear:
1. Wash the PCB.
2. Check the connector (where to connect the sensor).
Good luck ...Comment
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