Download Moon Jellyfish Datasheet

Moon Jellyfish
Frequency Analyzer and Display Driver
Narkidae.com
Revised May 2015
1 Features:
•
•
•
•
•
•
•
•
One Frequency Band Per Board
o Easy to Set 5th Order Band-pass
Filter
o Set With Two Resistor Values and
One Capacitor Value
On Board AC–DC Filter for:
o Voltage Controlled Display
o Microcontroller Sampling
Selectable AC or DC Output
o Jumper Can Bypass AC–DC Filter
PWM Brightness Control for Voltage
Controlled Displays
Adjustable Output Gain
o 1V/V to 101V/V
Wide Power Supply Range
o Single Supply 4.8V to 30V
o Dual Supplies 2.4V to 15V
Daisy Chainable
o Up to 16A Total System Current
All Standard Components Included
o User Provides Frequency Setting
Resistors
o Band-pass Filter Capacitor
Provided
2 Applications:
•
•
•
Frequency Band Visualizer
Microcontroller Frequency Analysis
General Purpose 5th Order Band-pass
Filter
3 Description:
The Moon Jellyfish is a frequency
analyzer and display driver board.
Frequency analysis is accomplished with
a 5th order band-pass filter. This filter is
easy to set, with only two resistance
values and one capacitance value
necessary. Following the band-pass
stage, the signal can either be fed strait
to the output or filtered to a DC value for
microcontroller sampling or display
driving. This selection is made with a
simple solder jumper. Also on board is a
parallel set of n-channel MOSFETs that
can be used to PWM a display to control
the brightness. The Moon Jellyfish is
designed to be daisy chained with a
maximum of 16A total system current.
Moon Jellyfish
Frequency Analyzer and Display Driver
Revised May 2015
4 Table of contents:
1 Features
2 Applications
3 Description
4 Table of Contents
5 Kit Contents
6 Specifications
7 Pin Configurations and Functions
8 Detailed overview
9 Application Information
10 Schematic
1
1
1
2
3
4
5
6
7
8
Narkidae.com
Moon Jellyfish
Narkidae.com
Frequency Analyzer and Display Driver
Revised May 2015
5 Kit Contents:
Qty
1
1
Value
BAT85
Green
Parts
D1
LED1
1
100Ω
5% 1/4W
680Ω
5% 1/4W
1,000Ω
5% 1/4W
10,000Ω
5% 1/4W
18,000Ω
5% 1/4W
100,000Ω
10% 1/2W
R12
2
BS170 (note 1)
Q1, Q2
1
LM324
IC1
2
2 position
5mm Pitch17.5A
JP1, JP2
2
3 position
3.5mm Pitch 17.5A
JP3, JP6
2
0.01uF
5% 100V 5P
C1, C2
1
0.1uF
10% 50V 2.5P
1uF
10% 25V 5P
C6
47uF
20% 35V 2.5P
C3, C4, C8
1
3
6
1
1
2
3
Picture
Brown Black Brown
R6
Blue Gray Brown
R4, R5, R8
Brown Black Red
R7, R9, R10, R11,
R13, R14
R15
Brown Black Orange
Brown Gray Orange
R16
C5, C7
(1) See “Moon Jellyfish BS170 pin-out to PCB” note
Moon Jellyfish
Narkidae.com
Frequency Analyzer and Display Driver
Revised May 2015
6 Specifications:
Absolute Maximum Ratings (Ta = 25C)
All voltages referenced to GND
Min
-0.3
Supply Voltage [VCC]
Large Screw Terminal [VCC], [GND] (1)
Small Screw Terminal [VCC], [GND] (1)
Signal Input [SIG_IN]
PWM Input [PWM_IN]
-18
PWM Output Current [PWM_OUT]
Operating Temperature (Ta)
TBD
(1) Total Vcc or GND current should not exceed 17.5A
Recommended operating conditions (Ta = 25C)
All voltages referenced to GND
Min
Supply Voltage [VCC]
4.8
Large Screw Terminal [VCC], [GND]
Signal Input [SIG_IN]
PWM Input high [PWM_IN]
4.5
PWM Input low [PWM_IN]
0
PWM Output Current [PWM_OUT]
Max
32
17.5
14
VCC/2.2
20
-1
TBD
Unit
V
A
A
Vpp
V
A
°C
Max
30
16
(Vcc-3)/2.2
18
0.8
-0.8
Unit
V
A
Vpp
V
V
A
Moon Jellyfish
Frequency Analyzer and Display Driver
Narkidae.com
Revised May 2015
7 Pin Configurations and Functions
PIN Name
Name
No
GND
1
SIG_IN
2
PWM_IN (1) 3
Type
Power
Input
Input
Description
VCC (large
connector)
GND (large
connector)
PWM_OUT
4,7
Power
Used for connecting ground of signal source
Input signal to be analyzed
Pulse width modulated signal input for controlling
display brightness. This pin can be left floating if
Vcc > 7 (PWM_OUT low)
Positive power supply
5,6
Power
Negative power supply
8
Output
SIG_OUT
9
Output
Used for controlling return current from the
display. State controlled by PWM IN.
Signal after analyzing. Can be either AC or
filtered DC (for driving voltage controlled display)
by using the solder jumper on the bottom of the
board
Used for supplying positive power to the display
VCC (small
10
Power
connector)
(1) PWM IN Can be left floating: PWM OUT will be low if Vcc > 7
Moon Jellyfish
Frequency Analyzer and Display Driver
Narkidae.com
Revised May 2015
8 Detailed Description:
Setting the Frequency:
The frequency is set by using the equations. R1, R2, and R3 depend on frequency
and will need to be supplied by the user. C1 and C2 have been provided and are
0.01uF 5% capacitors. Solve the first equation for R by plugging in your desired
center frequency (F0) and 0.01uF for C. Then solve the remaining equations. R1
should be at least 5*R but should be close to 5*R.
F0 = 1/(2πRC)
R1 > 5R
R2 = R3 = R
C1 = C2 = C
Setting the Output Type:
The output can be set to either the signal after the band-pass filter (AC) or the signal
after the AC-DC Filter (DC). The output is set using the solder jumper on the bottom of
the board. The AC output may be useful if you want to look at the filter response on
an oscilloscope. The DC output is useful if you want to drive a voltage controlled
display or sample the data with a microcontroller.
Setting the AC–DC Filter:
The AC-DC filter response can
be changed by adjusting the
value of R6, R7 and C4. R6 sets
the charging characteristic and
R7 sets the discharging
characteristic.
Vc = Vac pk(1 – e^(-t/((R6||R7)*C4)))
It is usually easiest to just test different values until the desired level of filtering is
reached. Example values of R6, R7 and C4 (680Ω, 10kΩ, 47uF Respectively) have
been provided and give reasonably good results if used to drive a voltage controlled
display.
Adjusting the Output Gain:
The output of the AC-DC filter is passed through a gain stage that can be set between
1V/V to 101V/V by adjusting the trimmer resistor labeled “Output Gain”
Moon Jellyfish
Frequency Analyzer and Display Driver
Narkidae.com
Revised May 2015
9 Application Information:
Example Voltage Controlled
Display:
A voltage controlled display can
be created such as the one on the
left. It consists of several cascaded
sets of LEDs, transistor, diode and
resistors, with each set feeding a
signal to the next. Each set shares
common supply rails making
construction simple. As the signal
voltage rises, it is able to pass
through more diodes and turn on
more transistors which sink the
current for LEDs. The ground of
this circuit would be connected to
PWM_OUT in order to control the
brightness of the whole display.
Controlling the Display Brightness:
A voltage controlled display can be implemented such that it’s brightness can be
controlled by the Moon Jellyfish. If the display positive supply pin is connected to the
VCC pin on the small screw terminal and the display negative supply pin is connected
to the PWM_OUT pin, the display can be pulsed on and off by pulsing the PWM_IN
pin. By adjusting the duty cycle, the brightness can be controlled between fully off
(0% duty cycle) to fully on (100% duty cycle).
Moon Jellyfish
Frequency Analyzer and Display Driver
Revised May 2015
10 Schematic:
Narkidae.com