Magnetic head circuit for detecting magnetic ink on currency.

[[email protected]]

Dear All,

I need help in making the electronic circuit of Magnetic Ink Detector
which are used in fake currency detectors.
Normally these circuits use a magnetic head (same as used in stereos),
and make a beep sound when the magnetic part of the dollar is rubbed
against the magnetic head.

Please help with circuit and component details.

Thanks in advance.

Sajeev
[email protected]

 

[Luhan Monat]

Dear All,

I need help in making the electronic circuit of Magnetic Ink Detector
which are used in fake currency detectors.
Normally these circuits use a magnetic head (same as used in stereos),
and make a beep sound when the magnetic part of the dollar is rubbed
against the magnetic head.

Please help with circuit and component details.

Thanks in advance.

Sajeev
[email protected]

Magnetic ink on currency? News to me.

I've heard of it on checks, but that is not true as far as I know.
Those numbers on the bottom edge of the check are special Optical
characters.

 

[Jim Thompson]

Magnetic ink on currency? News to me.

I've heard of it on checks, but that is not true as far as I know.
Those numbers on the bottom edge of the check are special Optical
characters.

Last time I had any contact with the check reader business, the
encoding on the lower left of a check IS magnetic ink.

...Jim Thompson

 

[[email protected]]

Magnetic ink on currency? News to me.

US currency uses a magnetizable dust in one of the inks - black, I
think. You can run the bill past a magnet and then past a magnetic head
to check the magnetic "signature".

I've heard of it on checks, but that is not true as far as I know.
Those numbers on the bottom edge of the check are special Optical
characters.

They are called MICR printing, Magnetic Ink Character Recognition; the
scanning is done magnetically, not optically. You can buy
remanufactured toner cartridges for laser printers in order to print
MICR data on plain paper to create your own checks. It is possible,
since banks in the US now store all checks electronically as 200dpi
images, that MICR will give way to actual optical character
recognition.

 

[Luhan Monat]

Last time I had any contact with the check reader business, the
encoding on the lower left of a check IS magnetic ink.

...Jim Thompson

Jim,

Any idea why they did it that way? Seems that it would be much simpler
to do it optically and elimate the need for special ink.

 

[Jim Thompson]

Jim,

Any idea why they did it that way? Seems that it would be much simpler
to do it optically and elimate the need for special ink.

To avoid reading errors due to wild-ass signatures (such as mine
that overlap the numeric data.

...Jim Thompson

 

[Luhan Monat]

To avoid reading errors due to wild-ass signatures (such as mine
that overlap the numeric data.

...Jim Thompson

I just looked at my checkbook. The mag ink number runs right up under
the signature line. Yep, magnetic, good idea.

 

[Sjouke Burry]

Magnetic ink on currency? News to me.

I've heard of it on checks, but that is not true as far as I know. Those
numbers on the bottom edge of the check are special Optical characters.

I checked 50 euros and it sticks to a strong magnet in
certain places,so yes,the ink does seeme to be magnetic.

 

[Rather Play Pinball]

I took out a dollar bill reader out of an arcade game, not needed at home.
Took the reader apart. Sure enough, there is a magnetic head, positioned in
the middle of the reader, so that it can detect the magnetic serial numbers,
regardless of which way the bill is feed into the reader. And of course, it
has a series of IR pairs, supposedly to read the data stream as the bill
goes by.

Jack

 

[Ken Smith]

Dear All,

I need help in making the electronic circuit of Magnetic Ink Detector
which are used in fake currency detectors.

[...]
Magnetic ink on currency? News to me.

The US dollar has a magnetic ink on it. Some (perhaps most) venting
machines that take US bills use a magnetic head to check that there is a
pattern of magnetic ink down one stripe on the bill. They check that the
pattern is about the right amplitude too.

The toner in copiers is magnetic. In the past some people could fool the
machines with copies of bills. Even though I don't think there are any of
those left, I'm not going to get specific.

The whole process is done in something no smarter than the smaller PICs.

 

[Rich Grise]

Dear All,

I need help in making the electronic circuit of Magnetic Ink Detector
which are used in fake currency detectors.

[...]
Magnetic ink on currency? News to me.

The US dollar has a magnetic ink on it. Some (perhaps most) venting
machines that take US bills use a magnetic head to check that there is a
pattern of magnetic ink down one stripe on the bill. They check that the
pattern is about the right amplitude too.

The toner in copiers is magnetic. In the past some people could fool the
machines with copies of bills. Even though I don't think there are any of
those left, I'm not going to get specific.

The whole process is done in something no smarter than the smaller PICs.

It seems like, at one time, color copiers had special color sensors such
that if you were copying currency, it would intentionally screw up the
copy, or something like that.

But a decent scanner and decent printer...

I was talking with my brother about that one day, and he said he'd like
to do $100's, and stick them in the change machine at the casino. I
said, "I don't know - I think I'd almost rather be in trouble with the
feds than with casino security."

Cheers!
Rich

 

[[email protected]]

It seems like, at one time, color copiers had special color sensors such
that if you were copying currency, it would intentionally screw up the
copy, or something like that.

Digital color copiers have for some time included firmware to recognize
currency; try color copying a dollar bill. The machine will say
"ILLEGAL SOURCE MATERIAL" or something of the kind and will not print
anything.

But a decent scanner and decent printer...

Modern scanner driver software also has currency recognition built in.
Manufacturers refuse to divulge the details. Use Linux to get around
this.

Color laser printers encode the serial number, print date and other
information in the hardcopy so your handmade Benjamins can be matched
to the printer you bought in Staples.