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Electronics/Retail Capacitive Credit Card Signature Screens


Hi, I hate using the tethered stylus on credit card terminal point of sale machines.  I'm a bit of a germ-a-phobe and hate touching those pens.  Unfortunately, using a credit card edge or conductive object (coin) or your standard iphone capacitive stylus doesn't work.  Some research into these machines indicates that there is a ground wire that enables the stylus the be recognized.  Oddly, these capaciive screens will respond to a finger or normal iphone stylus when navigating for other reasons, just the signature function seems to require the tethered stylus.  Is there a way around this?  Perhaps a capacitive stylus with a large enough mass with a potential of "zero" volts acting as a ground?  I guess I could have misunderstood the function of the tether...maybe it isn't a "ground".  Thank you in advance for your help!

You say you've tried the stylus pens used for smartphones and tablets?  They work on somewhat the same principle in most cases. They work with some stores I've tried. The tether is not a ground a much as it is a signal path to verify the signature is real.

You can buy a stylus pen that works well on all smartphones I've tried at Dollar Tree for, yes, $1.00.

Second solution that might work for you: Use a credit card that does not require a signature; just wipe it and wait for receipt to print out.

I use a Visa card issued by Chase and I took the option when initializing it to not require signatures.  It just scans and receipt prints.  Exception is for large amounts over a threshold amount previously optioned.

I empathize with your dilemma - there are many who share your feelings, I am sure.

PS: And the new chip embedded credit cards to not require signature as far as I know.  


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Graduate electrical engineer with over 40 years in electronic design, manufacturing, project organization and patent review. Experience in fields of industrial and consumer electronics (audio, video, acoustics, etc.)

IEEE (Institute of Electrical and Electronics Engineers); Senior Life member AES (Audio Engineering Society), Fellow Life member

BSEE University of North Dakota

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