RF
john
A wirelss circuit is mounted on the Rat's head to record Rat's brain
acitivity. The board transmit the data to its receiver sitting outside
the Rat's cage. The RAT will be awake and moving around in its cage,
and the transmitter will be sending the data continuously for days.
The problem is that we do not want to interruput the recordings and
the transmitter battery dies after every two hours.
So, We thought that lets power up the transmitter circuit wirelessly.
The transmitter circuit requires 3.3 volts and 0.26mA of current. I
was wondering that how can I measure the field produced by the coils
in different parts of the cage.
1. Can anyone recommed any simple technique or device or circuit that
can help me to do that?
2. How can design the antenna for the transmitter board that can be
easily mounted area equal to the size of the head of the RAT?
3. Is there any mathematical relationship between the magnetic field
intensity and the antenna design?
Please advice!
Regards,
John
Jan Panteltje
<conph...@hotmail.com> wrote in
<b87d5fc2-e645-4eff...@m20g2000vbp.googlegroups.com>:
Use photocell?
Does 'rat' need darkness?
Bill Sloman
> On a sunny day (Thu, 26 Nov 2009 13:57:41 -0800 (PST)) it happened john
> <b87d5fc2-e645-4eff-9e3a-6b432bda5...@m20g2000vbp.googlegroups.com>:
If so, use infra-red photoemitters. Neither us nor that rat can see
850nm radiation, and silicon photocells are maximally sensituve to
850nm radiation.
But make sure that you don't need so much IR that you risk cooking the
rat.
--
Bill Sloman, Nijmegen
o...@uakron.edu
Steve Roberts
Tim Wescott
RFI-EMI-GUY
Two ideas
1. Install a magnet coil and DC rectifying diode wired to the battery.
Install a running wheel with strong magnets glued to its periphery. The
Rat will charge the battery for you while it exercises. Now on to next
problem as how to keep induced RF and EM fields out of Rat brain and
sensor as not to affect scientific results.
2. Install two batteries in parallel and change one or other on frequent
basis.
--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"�
"Use only Genuine Interocitor Parts" Tom Servo ;-P
john
No, the rat does not need the darkness. But do the photocells have
enough current and voltage to charge the battery. and can you
recommend some of them.
John
ChrisQ
> So, We thought that lets power up the transmitter circuit wirelessly.
>
> The transmitter circuit requires 3.3 volts and 0.26mA of current. I
> was wondering that how can I measure the field produced by the coils
> in different parts of the cage.
>
If you only need a very small current, a few milliwats, a simple
inductive pancake loop around the inside of the cage should provide
enough power. A few tens of turns in a bundle should do the trick.
Alternatively, if there is always light, even ordinary leds can function
as low power solar cells and they can be very small and lightweight...
Regards,
Chris