Comments for 5Volt

Comment on The MIDI Piano Instructor – now with code! by The MIDI Piano Instructor « adafruit industries blog

The MIDI Piano Instructor « adafruit industries blog — Sun, 27 Jun 2010 17:51:32 +0000

[...] decided to re-think the idea of piano training software by integrating the visual aids directly into the keyboard. The ‘MIDI Piano [...]

Comment on About by admin

admin — Fri, 25 Jun 2010 15:36:15 +0000

@MIloni, Given your figures you should get 60uV per uT against mine 500uV per uT. You should read something, actually, if a reasonable (variable !) magnetic field is applied. Try checking around an heavy transformer (not a mobile phone charger). If you get a complete zero you should check your build, your components and your multimeter.
Best Regards
A.

Comment on About by MIloni

MIloni — Fri, 25 Jun 2010 08:31:17 +0000

yes the dual supply is Ok. I measured it with a voltmeter. The battery has discharged so it is less than 9 volts(around 8 volts)
the dimension of the core are 4.5cm*5.5 cm. Thoughthe turns are only 80 and they dont cover this entire area.The number of turns are v less but atleast some voltage should be induced.

Comment on About by admin

admin — Wed, 23 Jun 2010 11:52:02 +0000

Is the dual supply OK ? did you measure it with a voltmeter ?
What is the size of your foam core ?

Comment on A simple low frequency magnetic field flux meter by admin

admin — Wed, 23 Jun 2010 11:50:23 +0000

I’m not sure I got it : the circuit can measure VARIABLE magnetic flux, not static as it is the one from a steady magnet. Infact if you move the magnet you get an instantaneous reading that settles to zero after a short while.

Comment on About by MIloni

MIloni — Wed, 23 Jun 2010 07:20:41 +0000

Dear Alessandro,
I am exactly following your circuit but am unable to get the output. I have used TC7660 with the circuit you have recommended to reduce the ripple. But i think the number of turns are not enough. I am putting the windings on a foam squarish piece and have put around 80 turns. With your calculations, I should have more turns but atleast I should be able to get some voltage. please help
thanks in advance

Comment on A simple low frequency magnetic field flux meter by Anthony

Anthony — Tue, 22 Jun 2010 18:08:12 +0000

Hi pls i designed an inductor coil circuit but my problem is there is little or no diffrence when a magnet is broght close to the circuit.it gives a starting reading at 5 volts and when a magnet is brought i hardly see any diffrence in a the readings from the volts meter. please help

Comment on About by admin

admin — Sun, 13 Jun 2010 07:36:38 +0000

@MIloni, once you’re done with the project send some pictures !
Now, if simpler ICL7660 means fewer capacitors across the power supply (in and out), just leave them in place because they
are necessary regardless the datasheets because to voltage inverter IC is not very stable and has some bad ripple at its output.
You can choose whatever output level you want given a mag field input, just place the values in the equations and find the number of turns you need. 500 uV is a good tradeoff : reasonable number of loops and reasonable amplifier gain for a reasonable household field.
Ciao
Alessandro

Comment on A simple low frequency magnetic field flux meter by admin

admin — Sun, 13 Jun 2010 07:30:19 +0000

@MIloni,
plastic box is fine. No problem if the winding overlaps at some points.
B.R.
Alessandro

Comment on About by MIloni

MIloni — Sat, 12 Jun 2010 06:10:23 +0000

Thanks for previous help on lfmf magnetic flux meter. The ICL7660 has a simpler circuit that i found for conversion. Do I need to connect the ICL part that way. Also why are we saying 500uV across the end of the coil. Any particular reason? Can I also use that fact and also that Bcos(wt)= 1uV. What is the reason for that and should I use it too? if the battery itself has millivolt ripple will it not superimpose on the magnetic field?
please help me
thanks in advance
awaiting ur reply