FUNCTION GENERATOR
IME 458
BY KRISTOFER RAUNBORG
ELECTRONICS-DIY
•
Ordered parts from Electronics-DIY
•
Shipped within 10 days.
•
Total cost for the kit was $40
•
$50 total after tax and shipping
•
Came with the components, PCB, and a
piece of paper with schematics and
some instructions
http://electronicsdiy.com/product_details.php?pid=537&
name=1Hz%20%202MHz%20XR2206%20Function%20
Generator%20Kit
BILL OF MATERIALS
RefDes
FG
FAO
SW1
SW2
SW3
U1/2H1
3H1
P1
P2
P3
C1
C2, C4
C3, C7
C5
C6
Value
R1, R4, R5
R2
R3
6.8K Ohm
200 Ohm
1k Ohm
B100K
B10K
B100K
100uF
100nF
10uF
1nF
150pF
Count
1
1
1
1
1
2
1
1
1
1
1
2
2
1
1
3
1
1
Description
XR2206 Function Generator
RCA Connector/Output
4 DIP Swich
(Sine/Triangle)/Square Switch
Sine/Triagle Switch
2 Pin Header
3 Pin Header
Course AdjustmentPotentiometer
Fine Adjustment Potentiometer
Amplitude Control Potentiometer
Polar Capacitor
Capacitor
Polar Capacitor
Capacitor
"
1% Tolerance Resistor
"
"
Package Type
DIP
RCA Female
DIP
Switch box
"
Header
"
Pdial
"
"
Aluminum Electrolytic
Ceramic/Film
Aluminum Electrolytic
Ceramic
"
Film
"
"
DESIGNING ON DIPTRACE
•
DipTrace was used to design the Function Generator PCB.
•
Component and pattern libraries were made for each part.
•
Checked Function Generator IC datasheets.
• Only basic information found on Digi-Key such as max voltage and frequency.
•
Measurements were based on personal measurements taken with a caliper
rented from the lab. Triple checked.
•
Arranged PCB design with a 3 inch X 3.75 inch board cutout; set patterns first
and then used autorouter; cleaned up autorouter and checked circuit
•
Used a bigger board design so that soldering would be easier.
•
Final PCB design was printed out in 1:1 scale to determine if parts would fit.
•
Gerber files and NC Drill files were then created and sent to manufacturer.
PROTOTYPE
• Bought bread board and wire from IEEE
total fee of 5 dollars.
• Tested circuit at senior electronics
project lab BLDG 20 RM 111
PROTOTYPE
•
The initial prototype had a messy
signal especially at higher frequencies.
•
This was most likely caused by the
induction of the wires setup
throughout the circuit and due to flimsy
connections
•
Hoping that solid solder joints would fix
this.
PWB
•
PWB came in the mail with
two copies
TIME TO SOLDER!!!
SOLDERING
• A standard heating element,
sponge, and solder wire
with flux were used from the
IME lab to solder the
components.
• Tape was used to hold
components on the
opposite side down in order
to solder more accurately.
• After soldering alcohol was
used to clean away the left
over flux.
FINAL TESTING
FINAL TESTING
•
Went back to senior project lab to test
the final product.
•
Worked great on the first try.
•
Interestingly it can run on as low as an
8V DC input.
•
Here is a picture of the square wave
setting to the right running around 2MHz
using an 8V DC input.
@ 1 MHz
8V DC Input
Only Changing
Switch Orientation
Sine Wave
Square Wave
Triangle Wave
(Different time step value)
COMPLETED PROJECT
•
•
Powered by 9V-18V DC
The red DIP switch controls major
frequency setting. 100Hz to 2MHz
• FG IC only rated to 1MHz but 2MHz
setting works
•
Left most potentiometer controls
course adjustment (best in the
middle of bandwidth)
•
Middle potentiometer is Fine
adjustment
•
Right potentiometer is Amplitude of
signal (only changes very slightly
unless all the way down CCW)
COMPLETED PROJECT
•
RCA out located next to input for
power supply.
•
One switch on two headers used to
change signal from sine or triangle
to a square wave.
•
One switch on three headers used
to switch between sine wave and
triangle wave outputs. (If square is
set this switch does nothing.)
WHAT WAS LEARNED
•
The switches do not protrude enough from the PCB board to be able to mount
them inside the project box where they will be easy to reach.
• The potentiometers do extend past the board enough to reach once placed in the
box.
•
The RCA out is also in an awkward position on the board.
• It would have been easier to arrange all of the input/output components on one
side of the board to fit any container chosen later better.
• Can add wires that lead to outside of the box for inputs.
•
Frequency Switch box is unusable inside the box.
• Would have to totally redesign PCB in order to be able to use the generator from
inside the box.
Moral - *Plan Ahead*
FUTURE PLANS
•
Resolve problems occurring from PCB orientation with project box.
• Off PCB routing.
•
Intend to machine project box and mount function generator inside.
• Will add open section so that you can adjust the frequency switches.
•
May figure out how to hook up function generator to a computer and test using
National Instruments LabVIEW.
•
Decorate box with flames and other cool decals.
•
Add internal power supply to the projective housing and an on switch.
THANK YOU
REFERENCES
• http://electronicsdiy.com/product_details.php?pid=537&name=1Hz%20%202MHz%20XR2206%20Function%20Generator%20Kit
• http://www.digikey.com/product-detail/en/XR2206CP-F/10161305-5-ND/2411237