Harbor Freight
Model 90729

First posted
Sunday November 18, 2012 12:52
Monday December 17, 2012 10:41

Dear readers,

Battery Charging AA, AAA, 9V NiCd and NiMH pages complements this solar light discharging/chargiing page.

Large-scale solar generation of electricity may be a scam, we were told from two sources. So we're investigating by experimention, field trips, sales pitches, and reading.

fast neutron's post piqued our interest in solar generation of electricity.

fast neutron
Santa Fe, NM
January 12, 2009

From actual experience, wind farms produce 1.2 watts per square meter. Solar Thermal and Photovoltaic methods capture 5 to 6 watts per square meter. There is no economy of size in either technology. Dividing the watts you need by those values gives the land area in square meters needed to produce the juice. The numbers are astronomical

[Bill's post just before fast neutron's may have caused above post? :)]

MorganStanley VP was next stating that large-scale solar generation of electricity is a fraud.

MS lost $24 with the bankruptcy of Eclipse Aviation. Guess was going to be more careful about possible investments in New Mexico solar ventures.

Schott solar left Albuquerque.

Thursday December 13, 2012 08:54

How does the 90729 1) detect dark 2) turn on the LED?

Schematic drawn

from updated

Schottky diode drop from solar cell measured 198 mV.

Drop of several tenths of volts measured at test point 9 observed when LED illuminates.

But how does circuit work?

Dark detection appears to be done with voltage divider of the photoresistor [14, 8] on the and
R2 [11, 1].

Link to Fig. A circuit with explanation of how it works is analogous to what is seen here.

158-162 k Ohms measured between test points 14 and 18 when dark and 5 k Ohms when CDS photoresistor illuminated.

Output appears to go into pin 13 of the 66010.

NiCAD inserted in on-board holder. Ground from battery attached to free [ :) ] Harbor Freight digital low-side probe.

Solar cell covered in below photo and LED illuminated.

Only about 1.3x V or less comes out of the AA NiCAD.
Pin 14, input to the photoresistor, voltage!

This is output at pin 12 from the 66010.

Inability of measure on-board resistance of R!, R2 and R troubles us. So does the resistor color bands.
Monday December 10, 201 15:16


Author of Embedded Controller Forth of the 8051 Family reverse engineered 8085 forth with help from Forth Encyclopedia by Derik and Baker to learn how it worked.

Over a year was required.

Then Jerry Boutelle and the author ported 8085 forth to the 8051 as a Sandia National Laboratories job assignment.

Point is that if you want to intelligently work with a technology, then figuring out how it works is important.

Solar generation of electricity ... and possible large-scale fraud ... is under investigation.

Solar water pumping may be cost competitive with windmill pumping. AND no battery is required in most application because water can be stored in tanks.

No climbing of a tower is required to repair a solar water pumping system.

Pacific Hydrostar solar water pump examination

started with disassembly of pump with a belt grinder.!/bill.payne.790?fref=ts 

Message sent to Ms Mazhari from Cannon Beach, OR.

Municipalization: Boulder sees both sides now

Message sent to Ms Sahar Mehrrioz from Williams, AZ..

Solar POWER-GEN Keynote Session

Tweet link

Heart Hacker

Contact result of Ms Mehrroz's work.

Transparency and Better Forecasting Tools Needed for the Solar Industry
By Jennifer Runyon, Managing Editor,

billp37 a 10 MW solar PV array takes up about 7 acres. no long term damage to land. That is 10,000,000 watts / 28,000 sq meters = 353 Watts / sq meter no water resources used. Germany has 30 GW's installed = 30,000 MW / 10 MW x 7 acres = 21,000 acres In Ontario, Canada we have 105,000 acres of golf courses As well most solar goes on un-used rooftop space. China figures they have 100 million sq ft of flat roof commercial. equal to 23 GW's. Solar produces power at 31 grams of CO2 over lifetime, nat gas 600 grams/ kwhr. Most studies are done by people that do not fully understand the technology.

Response: none :)

Friday December 14, 2012 10:49

Albuquerque Journal appears to be pushing large-scale solar generation of electricity?

Where do journalists come from? They are manufactured in America's universities in a liberal arts curriculum.

Mark Mathis

Whitman college taught me:
Liberal arts 'educated' 'think' different. Most memorize, speculate, emote, then interpret.

Logic and reason does not work with them.

Ignoring facts is a liberal arts ploy.

Public scrutiny of them trying to ignore facts can get them to deal with facts. Grudgingly.

Google 'us food's s. valley warehouse show off roof array' to view full article.

Tapping Into Sun’s Power
By Richard Metcalf / Journal Staff Writer on Thu, Dec 13, 2012

The PNM electric meter was running backwards Thursday afternoon at US Foods’ 135,000-square-foot distribution facility, which recently installed a 430-kilowatt solar power array on the roof.

Mr Spiller explains why the meter does not spin backwards in New Mexico.

Displayed at The National Museum of Nuclear Science & History


RTECC conference attened on Tursday December 6, 2012.

Failed electronics in wind and solar generation of electricity systems may be irreplacable, we discussed.

Friday December 14, 2012 10:11

Hello RTECC.

A comment but first some background.

RTECC conference December 6, 2012

and I discussed


mechanical problems with wind generation of electricity, and obsoleting embedded controller products so as to force customers to upgrade to new systems.

Scam allegations in large-scale solar generation of electricity in New Mexico are under investigation.

Inclusion of embedded controller products where replacement parts may unavailable may also point to a scam?

Suppliers of smart meters, smart grid components, wind turbine and solar generation of electricity controllers systems may find that they are forced to upgrade embedded controller product and may not be able to supply their customers with replacement parts?

RTECC should issue a position statement on the embedded controller industry practice of deliberately obsoleting its products for business reasons for this could have bad consequences for power industries?

Reason is that non-technically educated individuals make decisions to include smart embedded controller products when they do not understand how most of the electronics and software industries work.

Please ack if you receive this email.

Please respond by January 7, 2013.


Tue, Dec 11, 2012

Public Service Company of New Mexico will add 20 megawatts of industrial-scale solar energy and 10 megawatts of its first-ever geothermal generation to utility’s electric grid.

That’s enough new capacity to supply electricity to 17,400 average homes.

The Public Regulation Commission on Tuesday unanimously approved PNM’s plan, which outlines the utility’s renewable procurements for 2013 and 2014. ...

Wednesday December 5, 2012

Solar panel .00 V, battery .67 V, battery drain -1.5 mA.

LED anode voltage .67 V? Mistake here?

Tuesday December 4. 2012

Solar panel .01 V, battery 1.34 V, current into LED -25.4 mA.

1.26 V should be at the anode of the LED. But why the voltage is present when the solar panel is charging the battery is puzzling. A mistake in test point placement?

Monday December 3. 2012

Full sun.

61.6 mA at 1.34 V is applied to AA NICD battery by solar panel outputing 1.77 volts.

1.48 V is apparently applied to the anode of the LED. LED is off. Mistake by us here?

Solar panel voltage is apparently reduced by .43 V by Schottky diode.

Low illumination charging.

Solar panel voltages are suprising high even with dim light. But little current it output.

Night. LED is on. Battery discharging.

Monday November 19, 2012

Sunday November 18, 2012 13:04

How does One Stop Gardens manage to show a profit on

Solar cell has plastic protective cover. Solar cells directly exposed to weather in our other 26 solar charging systems.


Stalk just above chip apparently is a CDS light sensor.

Light sensor fits in hole above back of solar cell.

7X scanner magnification.

Insulation on leads of CDS light sensor and tethering of apparent grounds at right of scanned image as well as clear plastic cover over solar cell indicated better construction than solar fence lights and stalk garden lights.

Monday November 19, 2012

Daylight photo of old 90729.

Night photo.

Single LED 90729 appear to produce as much light, if not more, the two LED fence lights.

Early evening photo of some of backyard solar lights.

Failure of a solar light causes us to disassemble it to find out failure cause.

Solar lights stayed on until dawn during summer. They do not in November 2012. Colder, shorter sun cycle.

Tuesday November 20, 2012

Point 4 [white wire] and 8 [blue] test points for voltages.

Battery current and voltage measured by insertion of an external AA NICAD.

NIMH experiment too? :)

Wednesday December 12, 2012 12:06

Harbor Freight solar fence lights model 67729 have all 4 failed, including the modified light illuminating scorpion silhouette James.

Rcently deployed fence light.


CDS light sensor seen above solar panel.

Deployed fence light after months of service.

Sun damaged solar panel.

Stopped working. Cause was low battery volatage. Charged battery installed and fence light resumed working. Old battery charged with Harbor Freight UNIVERSAL FAST BATTERY CHARGER.
Old battery charged to 1.38 volts. Solar cell charging system may be at fault.

This page is formatted with CSS by the author