Motion Encoder
Upgrade Kit
(Order Code: MEU-VDS)
The Motion Encoder Upgrade Kit is
an add-on product to be used with an
existing Vernier Dynamics System,
which is part of the Vernier Motion Encoder System
*
. It cannot be used on its own.
The encoder system allows the precise study of dynamics cart motion without the
use of ultrasonic motion detectors. The system consists of several parts:
A track with an encoder strip along the length of the track
A dynamics cart with an optical encoder and infrared (IR) transmitter
A receiver, attached to the end of a track
The encoder strip consists of alternating black and white bars with a 4 mm period,
allowing the optical sensor to detect the passage of the bars as the cart moves. With
two sensors appropriately placed, a change in position with 1 mm resolution can be
determined, as well as the direction of travel. A narrow infrared beam transmits
motion data to a receiver.
No alignments or adjustments are necessary, as the receiver attaches firmly to the
track, and the cart rides in slots on the track. The IR beam is not disturbed by
reflections from nearby objects.
The system is designed for use in physics and physical science courses for motion
and energy experiments. An optional Optics Expansion Kit (order code: OEK)
converts the track to an optics bench.
Some typical experiments done with the system include
Motion under zero acceleration
Motion under constant acceleration with the ramp inclined
Inelastic collisions using the included hook and pile tabs
Elastic collisions using the included magnetic bumpers
Parts Included with the Motion Encoder Upgrade Kit
Motion Encoder Transmitter
Motion Encoder Receiver
Motion Encoder Strip for application to 1.2 m or 2.2 m track
Mounting hardware for Dual-Range Force Sensor and accelerometers
Allen wrench 3/32 inch
*
Patent Pending
2
One-Time Assembly Instructions
Motion Encoder Strip Application
The track must have an encoder strip applied for the cart to determine its motion.
The strip is applied immediately next to the center slot, between the slot and the
numeric scale on the top surface of the track.
1. Clean the track surface with a damp cloth, and allow to dry.
2. Pull about 10 cm of backing off of the strip.
3. Align the strip next to the center slot, within 1 cm of the track end. The strip need
not extend all the way to the end of the track, but it can.
4. Carefully press down the strip, working your way along the track and removing
the backing as you go. Keep the strip edge right next to, but not hanging over, the
center slot. Do not stretch the strip.
5. Remove the rest of the backing, and press the strip down on full length of the
track.
6. Trim any excess strip from the track end.
If a track is to be used with a second encoder system, apply a second strip to the
other side of the center slot.
Motion Encoder Transmitter Installation
The Motion Encoder Upgrade Kit includes the parts to convert an existing dynamics
cart to a Motion Encoder Cart. Either a Standard Cart (CART-S) or a Plunger Cart
(CART-P) can be converted.
1. Remove the four end cap screws using the 3/32-inch Allen wrench.
2. Remove the end cap.
3. Place the cart upside down and press the wheels down towards the body to
compress the springs. Remove the pins holding the axle in place.
4. Lift out the axle and wheels.
5. Slide the encoder transmitter assembly into the cart body, battery end first, so the
power button and LED will be at the open end of the cart.
6. Replace the axle and pins.
7. Tighten the four bottom screws holding the encoder assembly, but leave them a bit
loose for now to allow it to align properly with the end cap.
8. Take note of the LED. It will be parallel to the circuit board. The tip projects
about 2
3 mm past the circuit board.
9. Install the end cap, being careful to allow the LED and power button to find their
places in the end cap. There should be no force required at all.
10. Replace two of the screws from the original end cap into the new cap using the
Allen wrench.
11. Tighten the four bottom screws the rest of the way so everything is held tightly in
place.
12. Insert two AAA batteries as indicated on the circuit board.
