• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Self-charging Graphics Tablet Pens - EMI

pnielsen

Member
This is a hardware related question. A lot of the new graphics tablets have self-charging, battery-less pens. I assume the charging is inductive, either off the screen surface or from an antenna within the tablet.

Can anyone please tell me more precisely how this works, at what approximate frequency, and if it represents a source of possible interference to data processing devices in close proximity?
 

Pommie

Well-Known Member
Most Helpful Member
Haven't come across these but the Wacom pads we used (from the early 90s) had batteryless pens that didn't require any power. Your assumption may be wrong.

Mike.
 

MacIntoshCZ

Active Member
My sister has wacom and the pen doesnt have a battery
 

Pommie

Well-Known Member
Most Helpful Member
If they could do battery less pens 30 odd years ago, why would they now require a battery? Makes no sense.

Mike.
 

gophert

Well-Known Member
Most Helpful Member
Pommie
I think you are stuck in the 1990s. you are talking about a "stylus". A pencil has many more capabilities like pressure sensing & accelerometer for shading and line width that makes it act like, umm, a pencil, or a fountain pen, or paint brush, or eraser

Look up: Apple Pencil or dozens of knock-offs.
 

gophert

Well-Known Member
Most Helpful Member
This is a hardware related question. A lot of the new graphics tablets have self-charging, battery-less pens. I assume the charging is inductive, either off the screen surface or from an antenna within the tablet.

Can anyone please tell me more precisely how this works, at what approximate frequency, and if it represents a source of possible interference to data processing devices in close proximity?
the Apple Pencil version 1 charged from the USB charging port on the iPad. Version 2 charges inductively from a dedicated antenna for the charger. The iPad has many more antennas for wifi, gps, bluetooth, and main battery wireless charging (receiver)...

the charger antennas are "focused" with ferrite modules to compete the magnetic "circuit" to maximize the energy transfer. Small neodymium iron boride magnets are used to hold the pencil in place and align the transmit and receive antennas of the wireless charge to maximize power transfer.
 

Pommie

Well-Known Member
Most Helpful Member
Pommie
I think you are stuck in the 1990s. you are talking about a "stylus". A pencil has many more capabilities like pressure sensing & accelerometer for shading and line width that makes it act like, umm, a pencil, or a fountain pen, or paint brush, or eraser

Look up: Apple Pencil or dozens of knock-offs.
Actually, back in the 90's we had Wacom tablets that had pressure sensing, yes, only 6 bit but totally above what people could conceive. And, Apple, wouldn't touch with yours.

Mike.
Edit, looks like Apple knocked of Wacom!!!!!
 
Last edited:

Latest threads

EE World Online Articles

Loading
Top