Maglev Diagram

Electromagnetic Levitation System
1. Description
The electromagnetic levitation system controls the magnetic field generated by an electromagnet
to levitate a small magnet in midair. The small magnet levitates in the air indefinitely without any
disturbance. The vertical position of the levitating magnet is measured using a linear Hall effect sensor
and the current in the electromagnet iscontrolled using a digital signal controller. The system has three
push buttons to adjust the vertical position of the levitating magnet and to apply a sinusoidal, square or
sawtooth reference signal. Both the amplitude and frequency of the reference signal can be adjusted
using the push buttons.
2. Circuit Schematic
The circuit diagram of the system is as shown in Figure 1.
U3

L1
15 mHA1321

SI S- S+

+5 V

+5 V

U2
P+
C4
1u

B1 +
9V

+5 V

LM780 5

E-

C3
1000 u

Q1
NTD4858N

R2
1k

C2
1 00 n

18 1 7 1 6 15 14 13 1 2 1 1 10
P-

+5 V
D1
1 N58 17

D2

+5 V

C1
100 n

E+

R1
10 k

d sP IC3 0F201 1

U1
1

23

4

5

6

78

9

ABC

PC B

+5 V

Figure 1. Circuit diagram of the system.
3. OperatingConditions
• Supply voltage range: 7.5 V DC to 12.0 V DC
• Ambient temperature: 10 °C to 60 °C (50 °F to 140 °F)
4. Operating Instructions
Connect a standard 9 V battery or 7.5 V DC power adaptor to the system. The LED should light
up when power is applied. Hold the small magnet about 2 cm (3/4'') away from the electromagnet
while the power is on. If the orientation of the magnet is correct, themagnet will levitate in the air. If
the orientation of the magnet is not correct, it will try to turn around.

1

The system has three push buttons labeled as A, B and C to operate it in four distinct modes.
These modes are shown in Figure 2 as circles. They are called “constant”, “sinusoidal”, “square” and
“sawtooth”. Transition from one mode to another is enabled by Button A. In “constant”mode, the
small magnet levitates in the air without any disturbance. The vertical position of the magnet can be
controlled within a range by pressing Button B (up) and Button C (down). In “sinusoidal”, square” or
“sawtooth” mode, the small magnet moves up and down within a range in accordance with a
sinusoidal, square or sawtooth reference signal. The amplitude and frequency of the referencesignal
can be adjusted using Button B (amplitude) and Button C (frequency). The system initializes itself in
“constant” mode after each power up.

Abbreviations
amp
dec
dis
frq
inc
max
mid
min

amplitude
decrease
distance
frequency
increase
maximum
mid point
minimum

Figure 2. Flow chart for the operation of the system.
2

5. Kit Assembly
The electromagnetic levitationkit requires both electrical and mechanical assembly. Assembly
instructions are detailed below.
5.1. Items Required (not included)
9 V battery

7.5 V power adapter

Screw driver

Diagonal cutter

Needle-nose pliers

Soldering iron

Solder wire

Super glue

5.2 Parts Included
1 x dsPIC30F2011 controller

1 x A1321 Hall effect sensor

1 x 7805A 5 V regulator

1 x NTD4858NMOSFET

U1

U3

U2

Q1

1 x 1N5817 Schottky diode

1 x LED

D1

D2

R2

R1

2 x 100 nF capacitor

1 x 1 µF capacitor

1 x 1000 µF capacitor

1 x 15 mH inductor (coil)

C1, C2

C4

C3

L1

3 x tactile switch

1 x 9 V battery snap

1 x magnet (either)

1 x 7'' 2-conductor cable

A, B, C

B1

M1

K1

1 x 6'' 3-conductor cable

1 x 2'' x 2'' PCB1 x aluminum base

1 x aluminum piece

K2

P1

A1

A2

4 x nylon spacer

5 x self-adhesive rubber

6 x 4-40 screw

1 x 8-32 screw with nut

H1, H2, H3, H4

F1, F2, F3, F4, F5

S1, S2, S3, S4, S5, S6

S7, N1

1x1k

3

resistor

1 x 10 k

resistor

5.3 Assembly Instructions
Electrical assembly
• Mount the components U1, U2, Q1, D1, D2, C1, C2, C3, C4, R1,...