PASCO ME-9259A User manual

012-01231C
10/95
$1.00
LASER SWITCH
Switch. On the tube of the switch, indicated by the
label, is a small green DOT (LED). With the laser beam
aimed down the axis of the tube, align the Laser Switch
such that the DOT lights up as brightly as possible. The
Laser Switch is now properly aligned with the laser.
Caution: Never attempt to align the laser switch
by sighting with your eye. Never look directly into
the laser. Never use a laser with an output exceed-
ing 0.5 mW unless you are wearing laser safety
glasses and the instructor is present.
The PASCO Model ME-9259A Laser Switch is a high
performance photo switch which utilizes a laser (such as
PASCO Models OS-9171 and SE-9367) as a light source. It
is extremely valuable in the following situations.
➀When the interruption of the photogate is of very short
duration. Since the rise and fall times of the ME-9259A
are on the order of 200 nanoseconds, this Laser Switch
can easily “see” interruptions on the order of 1 micro-
second.
➁When the photodetector must be located more than a
few inches from the light source. This is necessary if
the object to pass through the photogate is large, or if
the object’s trajectory is not easily controllable, or if a
combination of mirrors is to be used to allow one laser
and one Laser Switch to start and stop the timer. See
Figure 1.
Set-Up and Alignment
➀If the distance between the laser and Laser Switch is 5
m or less, a 0.5 mW laser is probably sufficient.
Beyond 5 m, a more powerful laser must be used.
➁Align the Laser Switch such that the laser beam is
incident upon the input port at the end of the Laser
Figure 1
LASER ME-9259A
LASER SWITCH
MOVING
OBJECT
MIRROR MIRROR
Instruction Sheet for
the PASCO
Model ME-9259A
Model ME-9259A
LASER SWITCH
scientific

012-01231C
2
➂Connect the Laser Switch stereo phone plug to a PASC0
Photogate Timer, Counter/Timer/Frequency Meter, or
Computer Interface. Interrupt the beam manually to
check that the timer changes state (starts or stops) as the
interruption occurs.
If other than a PASCO Timer or Computer Interface is
used, see the schematic for proper power and signal
connections.
➄Use a stereo phone plug extension cord (PASC0 Model
PI-8117) for increased separation between the photogate
and the timer.
Specifications
Detector Rise Time: 150 nanoseconds
Output States: High when detector is illuminated
Low when detector is not illuminated
TTL and CMOS compatible.
Power Requirements: 5 VDC at 45 mA
GROUND
OUTPUT
+5VDC
Stereo Phone Plug
2
6TH
TR
VCC
DIS
8
7
3
OUT
GND RCV
U1
555
R1
10KΩ
R2
220ΩR3
390Ω
Q1
MRD-3050
14
5
N/C N/C
R4
82Ω
Q2
2N3906
LED1
(GRN)
+5V
OUT
GND
SCHEMATIC
Q1
R1
Q1
R3
R2
R4
TAB
Q2
+
-
o
E
C
B
Component Layout
Notes:
➀All Resistors are 1/8W, +/- 5%
➁Output LED
Light=1 ON
Dark=0 OFF
Limited Warranty
PASCO scientific warrants this product to be free from
defects in materials and workmanship for a period of one
year from the date of shipment to the customer. PASCO
will repair or replace, at its option, any part of the product
which is deemed to be defective in material or workman-
ship. This warranty does not cover damage to the product
caused by abuse or improper use. Determination of whether
a product failure is the result of a manufacturing defect or
improper use by the customer shall be made solely by
PASCO scientific. Responsibility for the return of equip-
ment for warranty repair belongs to the customer. Equip-
ment must be properly packed to prevent damage and
shipped postage or freight prepaid. (Damage caused by
improper packing of the equipment for return shipment will
not be covered by the warranty.) Shipping costs for
returning the equipment, after repair, will be paid by
PASCO scientific.
Equipment Return
Should this product have to be returned to PASCO scien-
tific, for whatever reason, notify PASCO scientific by letter
or phone BEFORE returning the product. Upon notifica-
tion, the return authorization and shipping instructions will
be promptly issued.
NOTE: NO EQUIPMENT WILL BE ACCEPTED
FOR RETURN WITHOUT AN AUTHORIZATION.
When returning equipment for repair, the units must be
packed properly. Carriers will not accept responsibility for
damage caused by improper packing. To be certain the unit
will not be damaged in shipment, observe the following
rules:
➀The carton must be strong enough for the item shipped.
➁Make certain there is at least two inches of packing
material between any point on the apparatus and the
inside walls of the carton.
➂Make certain that the packing material can not shift in
the box, or become compressed, thus letting the
instrument come in contact with the edge of the box.
Output:
Source = 40mA @ 4.9V
Sink = 20mA @ .2V
➃