133 lines
5.8 KiB
Plaintext
133 lines
5.8 KiB
Plaintext
|
|
|
|
|
|
|
|
(word processor parameters LM=8, RM=75, TM=2, BM=2)
|
|
Taken from KeelyNet BBS (214) 324-3501
|
|
Sponsored by Vangard Sciences
|
|
PO BOX 1031
|
|
Mesquite, TX 75150
|
|
|
|
There are ABSOLUTELY NO RESTRICTIONS
|
|
on duplicating, publishing or distributing the
|
|
files on KeelyNet except where noted!
|
|
|
|
May 16, 1993
|
|
|
|
MAGCHECK.ASC
|
|
--------------------------------------------------------------------
|
|
This file shared with KeelyNet courtesy of Mark Mansfield.
|
|
--------------------------------------------------------------------
|
|
Anyone need a way to check magnetic fields? Well here's a circuit
|
|
that will allow you to do just that! It is simple, low cost, and
|
|
if calibrated can be very accurate.
|
|
|
|
It will distinguish between north and south poles. It does this by
|
|
outputing a voltage ABOVE 1/2 supply voltage for north poles and
|
|
outputing a voltage BELOW 1/2 supply voltage for south poles. This
|
|
causes the meter to either swing above center zero for north poles
|
|
and below zero for south poles.
|
|
|
|
The Hall effect sensor has a side that is the measure side and as
|
|
long as you have it toward the magnet it will tell you which pole it
|
|
is and its relative strength.
|
|
|
|
If you want to calibrate the instrument for gauss field reading, you
|
|
will have to come up with either a calibrated magnet or build you a
|
|
circuit to do the calibration. That's beyond the scope of this
|
|
paper. If you need such a circuit, let me know and I'll send you a
|
|
copy of it.
|
|
|
|
The construction is straight forward and does not require a circuit
|
|
board. Just use point-to-point wiring. Anyone with electronics
|
|
background should have no problems building it.
|
|
|
|
I mounted my sensor on a piece of 2 conductor shielded wire about 3
|
|
feet long. This allows me to move the sensor around freely. I
|
|
mounted the components is a small aluminum box. I used a small wall
|
|
transformer to supply the power for the circuit although it could be
|
|
battery powered just as easily. No big tricks or surprises in this
|
|
circuit. Just simple and works!
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Page 1
|
|
|
|
|
|
|
|
|
|
|
|
+ 12V
|
|
| DC
|
|
_|_
|
|
| | 1000
|
|
| | ohm
|
|
+ 12Volts DC |___| res.
|
|
| |
|
|
___|_____ CAL. Pot. _ _|_
|
|
| Hall | ______ / \ | |
|
|
| Effect | _______| 10K |_________/ \________>| | 200
|
|
| Sensor | | |______| \ / |___| ohm
|
|
|__________| | ^ \ _ / | pot.
|
|
| |_______| _|_
|
|
| 50 uA | | 1000
|
|
///// Meter | | ohm
|
|
zero center |___| res.
|
|
UGN3501U |
|
|
SEE NOTE |
|
|
BELOW |
|
|
/////
|
|
|
|
SPECIAL NOTE: The value of the bottom 1000 ohm resistor may have to
|
|
be changed slightly from the 1000 ohms. I had to add
|
|
200 ohms to it so my zero control was in its center
|
|
position when the meter was in the center position.
|
|
|
|
Parts List:
|
|
|
|
(1) UGN3501U Hall Effect sensor (Available from Newark
|
|
Electronics)
|
|
(1) 10K ohm pot. for calibration
|
|
(1) 200 ohm panel mount pot. for meter zeroing
|
|
(2) 1000 ohm 1% metal film resistors, 1/4 watt
|
|
(1) 50 microamp meter, preferably zero center
|
|
(1) regulated 12 Volt DC power source, 50 mA or more.
|
|
|
|
Note: If you have trouble finding the Hall Effect sensor, drop me a
|
|
note and I'll try to help you out.
|
|
|
|
Have fun!!!!
|
|
Mark Mansfield
|
|
--------------------------------------------------------------------
|
|
|
|
If you have comments or other information relating to such topics
|
|
as this paper covers, please upload to KeelyNet or send to the
|
|
Vangard Sciences address as listed on the first page.
|
|
Thank you for your consideration, interest and support.
|
|
|
|
Jerry W. Decker.........Ron Barker...........Chuck Henderson
|
|
Vangard Sciences/KeelyNet
|
|
|
|
--------------------------------------------------------------------
|
|
If we can be of service, you may contact
|
|
Jerry at (214) 324-8741 or Ron at (214) 242-9346
|
|
--------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
|
|
|
Page 2
|
|
|
|
|