LED Sensor Electronic Tracker

8/6/2019 LED Sensor Electronic Tracker

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LED3 LED Sensor Electronic Tracker with H-Bridge Drive.

LED3I decided to make a commercial surface mount PC board using the LED2 sensorconcept. It is quite sensitive and can track to a few degrees of accuracy in brightsunlight. If a blocking shadow is used the accuracy is better then 1/4, that's about asgood as you can get with an active feedback sensor. The board is a tiny .7"x1.4".Note! I have replaced the LED3 with the much more capable LED3X series of solartrackers. See below.This circuit uses power MOSFET drivers and is designed to operate satellite dishlinear actuators, however most any DC motor can be used. The power drivers arecapable of delivering about 10 amps of peak current, maybe more. When bettertransistors become available this current can be increased. The drivers operate theactuators in pulses of about .3 second every 3 seconds or a 10% duty cycle. Thiseliminates the needed for a heat sink on the transistors. Neat huh!

I haven't decided if 10% is the best duty cycle to use. Less will make the trackingslower but, we don't need speed anyway. I will determine this when I get betterweather. Slow tracking speed helps in partly cloudy condition. This prevents thetracker from making unnecessary movements when clouds move by.No electrical adjustments are required. The LEDs can be mechanically adjusted foroptimum tracking performance by aiming them after the circuit board is mounted.led3shadow

To improve accuracy, ie. with concentrators such as troughs or dishes, a blockingshadow can be placed in front. The shadow just covers the two inner LEDs whenaimed at the sun. Similar to the shadow on the Chace Tracker.I have used a band of metal about .5" in width at about 6" from the LED3. If theLED3 is used for E-W tracking the band is oriented N-S. Conversely, if the LED3 isused for N-S tracking the band is oriented E-W. The shadow device is not particularly

critical. For instance, I have used black electrical tape on the weather dome and itworked well.led3specifications

Power Supply Voltage

8 Volts to 22 Volts inclusive.The 8V minimum is specified to prevent damage to the MOSFETpower drivers. The damage is due to operating them in the linearregion with a load. This causes excessive power to be dissipated in theMOSFET with a resultant damaging temperature rise.The 22 volt maximum is defined by the voltage tolerance of 24Vprotection zener. This zener protects the power MOSFETs fromseeing damaging breakdown voltages. During testing I had severalfailures when operating from a car battery while the alternator was

Alternate Energy Page 1


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running. It was determined that the alternator was producing voltagespikes in excess of the 30V breakdown specification of the MOSFETs.The 24V zener has an initial tolerance of 5%. So the maximumcontinuous voltage that can be applied before conduction can occur is22.8V or so.Most PV panels don't output more than 22V in open circuit. Youshould check for sure. If they do go to high in voltage a simple powerregulator should be added to limit the maximum voltage.

Load Cu

rrent Continuous

5 Amp resistive.

The power MOSFETs are rated at over 10A at 25F. A conservativederating of 50% is prudent especially in hot weather conditions.

Load Current Intermitant

10 Amp intermitant at 10mS width once per timing cycle.The Power MOSFETs have an absolute maximum current rating of30A, but this is with ideal conditions where the temperature is 25Fand very fast gate rise times. The LED3 has a relatively slow gate risetime and may be operated at quite high temperatures sue to theweather. I think 10A at about 10mS is adequate for normal trackingapplications.If higher current motors are required a power amplifier may beneeded. See:http://www.redrok.com/electron.htm#power

I should note that the satellite dish actuator I use normally consumesabout 290mA of current at 13.8VDC. This actuator is capable ofdriving a 15' dish with 1500lb of force. You don't need a highpowered drive, just a slow forceful one.Think slow!

Operating Temperature

-40F to 185F or -40C to 85C

semiconductor

Transistor's I've Used

mosfet

nch ------ ------ ------ ------ ------ ------ ------IRFB59N10D

100V 59.00A

25m 5.5Vth Single N-Ch TO-220,TO-262

withintegr

al100VZener

+-30VGate

$2.99

IRFP460

500V 20.00A

270m

4.0Vth Single N-Ch TO-247

withintegr

al500V

Zener

$6.28

IRF840

500V 8.00A 850m


withintegr

al500VZener

$2.79

FQP46N15

150V 45.60A

42m 4.0Vth Single N-Ch TO-220

+-25VGate

$2.08

STP40NF12

120V 40.00A


withintegr

al

$1.87



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120VZener

IRF520N

100V 9.70A 200m


withintegr

al100VZener

$1.23

NDP708AE

80V 60.00A

22m 4.0Vth Single N-Ch TO-220,T0-262AB

withintegr

al80V

Zener

$?.??

IRFZ48V

60V 72.00A


withintegr

al60V

Zener

$2.13

IRFZ44N

60V 55.00A

16.5m


withintegr

al60V

Zener

$1.68

RF1S50V60

60V 50.00A

22.0m

4.0Vth Single N-Ch TO-262AA

withintegr

al60V

Zener175C

$?.??

MTP50N06V

60V 42.00A


withintegr

al60V

Zener

$?.??

IRFZ34

60V 30.00A


withintegr

al60V

Zener

$1.38

IRF1405

55V 169.00A

5.3m


withintegr

al55V

Zener

$3.02

IRF3

315

150V 27.00

A

70m 3.21Vt

h@3

4.0Vth

Single N-Ch TO-22

0

with

integral120VZener

IRF3315 Ron vs. Vgs

$1.86

IRF7313

30V 4.00A 29m 3.0Vth Dual N/N-Ch

SO-8 withintegr

al30V

Zener

$2.37

2N7002

60V 0.30A 5000m

2.5Vth Single N-Ch SOT-23

Phillips

NXP

$0.41



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+-30VGate

VN2222LL

60V 0.23A 7500m

2.5Vth Single N-Ch TO-92 $0.57

2N7000

60V 0.20A 5000m

2.45Vth

@303.0Vth

Single N-Ch TO-92,SOT-23

+-20VGate

2N7000 Ron vs. Vgs

$0.42

VN0106 60V 2.50A 5000m 2.4Vth Single N-Ch TO-92

VN0106 Ron vs. Vgs

$?.??

ZVN3306A

60V 0.30A 5000m


VN2106

60V 0.30A 6000m


HUF76137P3

30V 75.00A

9m 2.15Vth

@33.0Vth

Single N-Ch TO-220AB

withintegr

al30V

Zener

HUF76137P3 Ron vs. Vgs

$?.??

IRLI2203N

30V 61.00A

7m 2.01Vth

@32.5Vth

Single N-Ch TO-220InsulatedFullpack

withintegr

al30V

ZenerIRLI2203N Ron vs. Vgs

$1.70

IRL540N

100V 36.00A


withintegr

al100VZener

$1.23

VN10LP

60V 0.30A 5000m

1.92Vth

@302.5Vth

Single N-Ch TO-92

VN10LP Ron vs. Vgs

$0.68

SI3442DV

60V 4.00A 70m 1.8Vth Single N-Ch TSOP-6

+-8VGate

$0.66

IRLZ44N

55V 47.00A

22m 1.76Vth

@32.5Vth

Single N-Ch TO-220

withintegr

al55V

ZenerIRLZ44N Ron vs. Vgs

$1.67

BS107PT 200V 0.10A 28000m 1.76Vth

@302.5Vth

Single N-Ch TO-92E-line

BS107PT Ron vs. Vgs

$0.91

RFP30N06LE

60V 30.00A

47m 1.75Vth

@32.0Vth

Single N-Ch TO-220TO-263AB

withintegr

al60V

ZenerGate

Protection

RFP30N06LE Ron vs. Vgs

$1.09



5/9

Zener

IRF3708

30V 62.00A

12m 1.67Vth

@32.0Vth

Single N-Ch TO-220TO-262

withintegr

al30V

ZenerIRF3708 Ron vs. Vgs

$1.74

ZVN2106A

60V 0.45A 6000m

1.65Vth

@302.4Vth

Single N-Ch TO-92E-Line

ZVN2106A Ron vs. Vgs

$0.72

2SK3065

60V 2.00A 320m

1.5Vth Single N-Ch SC-62 GateProtec

tionZener

$0.83

ZVNL120A

200V 0.20A 10000m

1.35Vth

@301.5Vth

Single N-Ch TO-92

ZVNL120A Ron vs. Vgs

$0.78

DMN5L06

VAK

50V 0.30A 2000m

1.0Vth Dual N/N-Ch

SOT-563

withintegr

al50VZener

$0.58

DN2530

300V 0.17A 12000m

-1.0Vth


Depletion

Mode

$0.71

DN3545

450V 0.20A 20000m

-1.5Vth


Depletion

Mode

$0.82

CPC3

703

250V 0.36A 4000

m

-1.6Vt

h

Single N-Ch SOT-

89

Deplet

ionMode

VSG vs IS @ VDG of15V,10V,5V

$0.95

nchpch ------ ------ ------ ------ ------ ------ ------

Si4539ADY

30/-30V

4.90/-3.70A

36/53m

1.0/-1.0Vth

Dual N/P-Ch

SO-8 $2.06

Si4511DY

20/-20V

5.80/-3.710

A

33/500m

1.8/-1.4Vth

Dual N/P-Ch

SO-8 $2.06

Si450

0BDY

20/-20

V

5.30/-

3.10A

30/10

0m

1.5/-1.

5Vth

Dual N/P-

Ch

SO-8 $1.46

pch ------ ------ ------ ------ ------ ------ ------

Si1023X

-20V -0.40A

1200m

-0.8Vth

Dual P/P-Ch

SOT-563

$0.52

IRF7410

-12V -13.00A

7m -0.9Vth

Single P-Ch SO-8 withintegral -12

VZener

$2.03

Si4947ADY

-30V -3.90A

80m -1.0Vth

Dual P/P-Ch

SOIC-8

$1.22



6/9

SPP18P06P

-60V -18.60A

130m

-2.34Vth

@30-2.8Vt

h

Single P-Ch TO-220

SPP18P06P Ron vs. Vgs

$1.31

MTD5P06V

-60V -5.00A

340m

-2.86Vth

@30-4.0Vt

h

Single P-Ch DPAC 3pin

withintegral -60

V

Zener

MTD5P06V Ron vs. Vgs

$1.07

VP0610T

-60V -0.12A

10000m

-3.5Vth

Single P-Ch SO-23 -+30VGate

$?.??

IRF7316

-30V -4.90A

58m -3.0Vth

Dual P/P-Ch

SO-8 withintegral -30

VZener

$1.17

IRF9Z34

-60V -18.00A

140m

-3.13Vth

@30-4.0Vt

h

Single P-Ch TO-220

withintegral -60

VZener

IRF9Z34 Ron vs. Vgs

$1.39

IRF4905

-55V -74.00A

20m -3.30Vth

@3-4.0Vt

h

Single P-Ch TO-220

withintegral -55

VZener

IRF4905 Ron vs. Vgs

$2.81

IRF5305

-55V -31.00A

6m -4.0Vth

Single P-Ch TO-220

withintegral -55

VZener

$1.61

IRF5210 -100V -18.00A 60m

-4.0Vth

Single P-Ch TO-220 withintegral -10

0VZener

$2.66

bipolarnpn ------ ------ ------ ------ ------ ------ ------

KSC2330YBU

300V 0.10A 1.0W 120Hfe

Single NPN TO-92L

$0.11

2SD667

80V 1.00A 0.9W 160Hfe

Single NPN TO-92MOD

$?.??

2N2222A

75V 0.60A 0.5W 35Hfe Single NPN TO-18 MetalCan

$0.96

TIP120

60V 5.00A 1000Hfe

Single NPN TO-220

Darlington.12K/8K

$0.68

BC337

45V 0.80A 0.625W

60Hfe Single NPN TO-92 $0.44

BC550

45V 0.10A 0.5W 110Hfe

Single NPN TO-92 $0.52



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BD135

45V 1.50A 12.5W

40Hfe Single NPN TO-126

$0.62

MPSA18

45V 0.10A .625W

400Hfe

Single NPN TO-92 $0.52

2N3904

40V 0.20A 0.625W

40Hfe Single NPN TO-92 $0.42

pnp ------ ------ ------ ------ ------ ------ ------

2N39

06

-40V -0.2A 0.625

W

40Hfe Single PNP TO-92 $0.46

BC327

-45V -0.80A

0.625W

100Hfe

Single PNP TO-92 $0.43

BC560

-45V -0.10A

0.5W 110Hfe

Single PNP TO-92 $0.29

BD136

-45V -1.50A

12.5W

40Hfe Single PNP TO-126

$0.62

2N2907A

-60V -0.60A

.4W 75Hfe Single PNP TO-18 MetalCan

$0.92

2SB1181

-80V -1.00A

1.0W 180Hfe

Single PNP SC-63 $0.98

TIP127

-100V -5.00A

1000Hfe

Single PNP TO-220

Darlington.12K/8K

$0.60

regulator ------ ------ ------ ------ ------ ------ ------

LM317

40V 1.50A 1.25V

adj

100A

2.5V Positive

TO-220

LM317L

80V 0.10A 1.25V

adj

100A

1.9V Positive

TO-92

LM31

7

Positi

ve

Excel

fileopamp ------ ------ ------ ------ ------ ------ ------

LM124A

32V 20mA 3000Vos

0.5mHz

0.25V/S

Quad DIP-14

LM358A

32V 20mA 7000Vos

0.5mHz

0.25V/S

Dual DIP-8

AD8639

16V 19mA 23Vos

1.3mHz

2.50V/S

Dual SOIC-8

comparato ------ ------ ------ ------ ------ ------ ------

LM339A

36V 6mA 2mVos 1.3S 300nS Quad DIP-14

LM393A

36V 6mA 5mVos 1.3S 300nS Quad DIP-8

tempsensor ------ ------ ------ ------ ------ ------ ------

LM50BIM3X

4.5V-10V

130A

100mV

@ -40C

1750mV

@125C

+-2C Analog

SINGLE

SOT-23



8/9

diode ------ ------ ------ ------ ------ ------ ------

1N5404

400V 3.00A 1.00V@3A

3.00W

150C DO-201AD

Silicon

1N4004

400V 1.00A 1.10V@1A

3.00W

175C DO-201AD

Silicon

HSS82

200V 0.125A

1.00V@

100m

A

0.40W

200C DO-34

Schottky

1N4148

100V 0.30A 1.00V@

10mA

0.50W

175C DO-35

Silicon

PMBD7000

100V 0.215A

0.82V@

10mA

0.25W

150C Dual SOT-23

Silicon

BAW56

85V 0.200A

0.855V@

10mA

0.35W

150C Dual SOT-23

Silicon

MMBD4148

75V 0.200A

1.00V@

10mA

0.35W

150C SOT-23

Silicon

BAS416

75V 0.20A 1.00V@

10mA

0.25W

150C SOD323

Silicon

1N270

50V 0.040A

1.00V@

200mA

0.05W

90C 0.8pF DO-7 Germanium

SB540

40V 5.00A 0.55V@5A

2.75W

125C DO-201AD

Schottky

RSX501L-20

20V 5.00A 0.39V@3A

1.50W

125C SOD-106

Schottky

G331 20V 0.050A

1.00V@

5mA

0.05W

75C DO-7 Germanium

zener ------ ------ ------ ------ ------ ------ ------

2EZ110D5

110V@

4.5mA

17mA 2.00W

4000

150C 5% DO-41

Zener

1N4757 51V@250A

20mA 1.00W 1,5K 175C 5% DO-41 Zener

1N4625

5.1V@

5mA

70mA 0.40W

1.5K

175C 5% DO-35

Zener

BZX84C2V7LT1

2.7V@

5mA

83mA 0.225W

1.5K

150C 10% SOT-23

Zener

chace



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The circuit board and sensor assembly of the Chace tracker.The circuit is not water proof so a protective plastic dome is needed. I have used 2liter clear plastic soda bottles. They last a long time, at least 5 years for one I haveused, probably a lot more. This circuit will fit into the 20 Oz. size. The plastic bottlechosen needs to have a round bottom, the type that comes with the black plastic

bottom which is removed. The type with the molded in feet don't work very well asthey diffract the light too much.Glass jars are even worse optically if looking through the bottom.Any one out there with a good idea for a better weather dome?In Minnesota I have snow that builds up on the top of the dome. This snow is quitereflective and can confuse the sensors as to the correct direction for the brightestportion of the sky when in the sky is overcast. It's easy to just brush the snow of butthis is not always timely. I have experimented with putting black opaque paper insidethe dome to eliminate the light from the snow. Another paper light blocker can be putunder the sensors to stop the reflected light from the snow on the ground.dome

Dome on Chace tackerThis weather dome is made from a 2 liter pop bottle.

Pasted from

LED Sensor Electronic Tracker

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