In a message dated 26/06/2006, system98765@............. writes:

Just  wondering if anyone else was able to help me with my system. I know
that  others have similar systems.
Hi Kareem,
 
    If you say what pieces of equipment you are wanting  to connect together, 
you may get some more helpful advice. Do you have a  manufacturers, a model 
numbers and a handbook?
    Drum recorders have a motor which drives the drum.  It may also traverse 
the drum and / or the pen mounting may move. The pen will  probably have a 
separate drive. The drives may be direct drive, timer motor,  servo feedback 
motor or stepper motor. Which are yours?
    What are the voltage, current and resistance  ratings of the pen drive 
and which type is it? The oldest types were direct  drive, but used a fairly 
high current.
    The ? component is a preset variable resistor /  potentiometer. It might 
be used to zero the pen position or to set it's  sensitivity.
    What sort of geophone you are planning to use? The  4.5 Hz ones can be 
used for local earthquake sensing, but the 1 Hz ones are  commonly used for 
picking up all P and S waves. You can very  usefully extend the response of the 
4.5 Hz ones down to 0.5 Hz, but this  takes a additional amplifier. 
    Drum recorders are more often used for longer  period sensors. Larry used 
to sell all the electronics for a SG seismometer -  you just had to add a 1 
sec pendulum.
    It is much easier to analyse the seismic trace on a  computer screen. The 
higher frequency signals are likely to overlap on a  drum recorder.
    You will certainly need a signal amplifier / LP  filter and a power 
supply, but you may also need a high current amplifier to  drive the pen. How many 
pens do you need to drive? Some charts  recorders had just one pen, others had 
three or four.
 
    Regards,
 
    Chris Chapman

On  Behalf Of Jim E ODonell
Sent: Thursday, June 22, 2006 9:43 PM
Hi  Kareem-
You can not drive that galvanometer with a geophone- you will need  an
amplifier and filter.  The 28 hz will not see anything except  freq's higher
than ~20 Hz... Nice Pics tho- <<<   Jim
 

>  anyone can help out with connecting my seismograph drum 
> recorder  system (Photo A, see links below). It's an older model that 
> was once  used in a museum. I do have some basic electrical skills but 
> unsure  how to connect the sensor small geophone (Photo B) with two 
> leaders.  There is a specific part of the system that I'm not sure what 
> to do  what with (Photo C).
> The drum has a power switch and 
> rotates  fine but can't get it to behave like a seismograph system.
> 
>  Photo A  http://www.heyjoojoo.com/seismo/3 Photo B  
>  http://www.heyjoojoo.com/seismo/4 Photo C  
>  http://www.heyjoojoo.com/seismo/2 Extra photo with alternate view: 
>  http://www.heyjoojoo.com/seismo/1








In a message dated 26/06/2006, system98765@............. writes:
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>Just=20
  wondering if anyone else was able to help me with my system. I know
tha=
t=20
  others have similar systems.
Hi Kareem,
 
    If you say what pieces of equipment you are wan=
ting=20
to connect together, you may get some more helpful advice. Do you have a=20
manufacturers, a model numbers and a handbook?
    Drum recorders have a motor which drives the dr=
um.=20
It may also traverse the drum and / or the pen mounting may move. The pen wi=
ll=20
probably have a separate drive. The drives may be direct drive, timer motor,=
=20
servo feedback motor or stepper motor. Which are yours?
    What are the voltage, current and resistan=
ce=20
ratings of the pen drive and which type is it? The oldest types were direct=20
drive, but used a fairly high current.
    The ? component is a preset variable resistor /=
=20
potentiometer. It might be used to zero the pen position or to set it's=20
sensitivity.
    What sort of geophone you are planning to use?=20=
The=20
4.5 Hz ones can be used for local earthquake sensing, but the 1 Hz ones are=20
commonly used for picking up all P and S waves. You can very=20
usefully extend the response of the 4.5 Hz ones down to 0.5 Hz, but thi=
s=20
takes a additional amplifier. 
    Drum recorders are more often used for longer=20
period sensors. Larry used to sell all the electronics for a SG seismometer=20=
-=20
you just had to add a 1 sec pendulum.
    It is much easier to analyse the seismic trace=20=
on a=20
computer screen. The higher frequency signals are likely to overlap on=20=
a=20
drum recorder.
    You will certainly need a signal amplifier / LP=
=20
filter and a power supply, but you may also need a high current amplifier to=
=20
drive the pen. How many pens do you need to drive? Some charts=20
recorders had just one pen, others had three or four.
 
    Regards,
 
    Chris Chapman
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>On=20
  Behalf Of Jim E ODonell
Sent: Thursday, June 22, 2006 9:43 PM
Hi=20
  Kareem-
You can not drive that galvanometer with a geophone- you will n=
eed=20
  an
amplifier and filter.  The 28 hz will not see anything except=20
  freq's higher
than ~20 Hz... Nice Pics tho- <<< =20
Jim
 
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>>=20
  anyone can help out with connecting my seismograph drum 
> recorder=20
  system (Photo A, see links below). It's an older model that 
> was o=
nce=20
  used in a museum. I do have some basic electrical skills but 
> unsu=
re=20
  how to connect the sensor small geophone (Photo B) with two 
> leade=
rs.=20
  There is a specific part of the system that I'm not sure what 
> to=20=
do=20
  what with (Photo C).
> The drum has a power switch and 
> rota=
tes=20
  fine but can't get it to behave like a seismograph system.
> 
>=
;=20
  Photo A  http://www.heyjoojoo.com/seismo/3 Photo B  
>=20
  http://www.heyjoojoo.com/seismo/4 Photo C  
>=20
  http://www.heyjoojoo.com/seismo/2 Extra photo with alternate view: 
>=
;=20
  http://www.heyjoojoo.com/seismo/1