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Pull-string Generator from
Potenco |
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I suggested that this product be developed years
ago. Now someone has actually done it. Potenco’s product was originally
designed to provide third world countries with a means to produce electrical power for
low power devices, using human muscle. The power would typically be used to
charge a battery, which would then be used to power LED lights for nighttime
illumination. |
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By pulling on the string attached to their device, this
thing can generate 20 watts of peak power. This is plenty of power for a variety
of portable electronic devices. Cell-phones, laptop computers and battery powered
lights could all be charged by their device. I can image all kinds of other
applications. Perhaps a smaller version could be attached directly to the back
of a cell phone. A few quick pulls could give you more talk time. When
connected to a dead car battery, a few minutes of pulling on the string could put
enough juice in the battery to start a car. |
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| Tiny Solid State
Relay Handles High Power |
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Panasonic has a new line of
“PhotoMOS” relays, which provide 5000 volts of isolation and can switch a sizeable
amount of bidirectional AC or DC power. Their AQY212GH can switch up to 1 amp of
current with a voltage of 60v. It takes just 5ma of LED current to fully switch
the device. Their line of parts also includes devices which can handle higher
voltages at lower current. These light coupled relays are handy when a computer
needs to control power to an external device. They are available from Mouser.com. |
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Tiny Shock Sensor from Murata |
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This tiny sensor is only about the size of a 1206
surface mounted resistor. I have used this part on a couple new products I
designed. Murata’s PKGS-00LD is quite small but produces a sizeable voltage
whenever the circuit board assembly, which houses the surface mounted device, receives
a mechanical shock. It can detect machine vibrations or object impacts. I
used one to detect when the hammer of a handgun fell after the trigger was pulled for
a weapons training system. The devices are available from Mouser. |
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Datasheet |
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| User Friendly Adjustable Voltage
Regulator from Linear Technology |
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Linear’s LT3080 voltage requires just one
external resistor to set the output voltage. The 1 amp rated device can easily
be stacked in parallel with other devices, to increase the output current. The
input can range from 1.2v to 30v and it has a voltage drop of only 0.3v at full
current. The really neat feature of this new part is its ability to have its
output voltage set to zero volts. This makes it very handy for many applications
where a DC voltage of less than one volt is desired. It is available from
Digikey.com. |
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Data Sheet Link |
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| High Voltage
Schottky Diodes From Cree |
| Schottky diodes are generally used
when a lower voltage drop and higher switching speed is needed. These parts
can often lead to some real energy savings. However, most Schottky diodes
are not offered in voltages greater than about 60v. Cree has developed a new
line of high speed silicon carbide Schottky diodes with much higher voltage
ratings. Their CSD10060A device is rated at 600 volts and can handle 10 amps of
current. Although standard silicon power diodes can provide a slightly lower
voltage drop than Cree’s device, they can’t touch the super fast 50ns recovery
time of the Cree parts. I expect these devices to show up in high power switching
regulators and battery chargers. The parts are available from
www.digikey.com. |
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Aimtec Power Supply Modules
Replace 78XX Regulators |
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There are many circuits which call
for a 78XX type voltage regulator. However, in some applications, these
linear type regulators can be quite inefficient and may require a heat sink to
operate properly. Aimtec has a line of DC to DC converters, which are drop
in substitutes for the linear regulators. These converters offer a wide
input voltage range, a 2.5 watt output rating and up to 90% efficiency. This
can add up to a huge energy savings. It also means that no heat sink is needed.
They can be purchased from www.digikey.com. |
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Datasheet |
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Fisher
Electric Motors Provide Compact Power |
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Some 12 years ago I worked with an inventor by the name
of Gene Fisher. Gene developed a new electric motor that really shocked the
motor industry. His permanent magnet brushless motor design could crank out 10HP
in a device smaller than a standard Ľ horse motor. It weighed just seven pounds.
Gene is no longer alive but his company still lives. They claim a “sweet spot”
range between 10KW and 100KW. These light weight devices are perfect for any electric
motor or alternator application which needs to be small yet powerful. I think
when used with a compact speed reduction gear, these would be perfect for wind
generator applications. |
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Energy Harvesting Solar Cells from Clare |
| In many wireless applications, very
little electrical energy is needed. Information is gathered from some sensor
and then transmitted to a distant receiver in short infrequent messages.
Zigbee and other wireless protocols are commonly used. Instead of using a
battery, with its limited life, some products have switched a combination of a
tiny solar energy harvesting device and a supercapacitor. |
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the capacitor, which stores enough energy to deliver the peak power needed for
many low duty cycle wireless systems. Clare has made the job of converting
sunlight into useable electrical power easier with their 4 volt and 8 volt
devices. They have placed efficient solar cells in classic 8 pin and 16 pin
surface mounted IC packages, as shown below. Their product line shows 4
different parts as shown below. If you assume an average of 6 hours of
sunlight per day, the 100uA from the 4v part can pump about 8 watt-seconds
(joules) of energy into a capacitor. Two days of sunlight would completely
charge up a 1 farad supercapacitor. Mouser lists the CPC1822 part.
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CPC1822, 4v, 50uA, 8 pin SOIC
CPC1831, 8v, 25uA, 8 pin SOIC
CPC1824, 4v, 100uA, 16 pin SOIC
CPC1832, 8v, 50uA, 16 pin SOIC |
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4v part Data Sheet |
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8v part
Data Sheet |
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| Extremely Bright
Surfaced Mounted Green LED from King Bright |
| It is not often that
I get amazed by such a common part as an LED. But, after lots of searching and
testing of various LEDs for one of my clients, I came across a very nice part.
The APD3224ZGC-F01 surface mounted part from King Bright knocked my socks off.
This thing was fantastic. It is brighter by a long shot than anything else I had
tested. It emits an absolute blinding amount of light with just 10ma of current.
It is still quit visible, even with just 100uA of current. I wired in a string of 10
of these things in a night light, which used to contain white LEDs. The bright
green light takes a bit of getting used to but I have come to like it. This part
is available from both Digikey and Mouser. |
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Wide Range Ultrasonic Microphone from
Knowles Acoustics |
| A while back I had to measure the
sound intensity of 40KHz sound coming from a large piezoelectric transducer.
Many of the classic 40KHz sensors available had a very narrow response range,
centered on 40KHz, too narrow for my application. The SPM0204UD5-2 device
from Knowles has a nice flat 10KHz to 65KHz response. The part is available
from Digikey (part number 423-1086-1). |
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| Great Night Light From
Leviton |
| OK, this is not a
high tech product, but after decades of frustration in dealing with poorly design LED
night lights and standard incandescent night lights, which last only 3 months, I
finally found a product which pleases me. This is an inexpensive compact
florescent lamp, which produces a very nice amount of light, is energy efficient and
has a very long life. The MINFL night light from Leviton, shown below, shows no
letup after three full years of 24/7 operation in my bedroom. Its simple ballast
design means fewer parts to fail. It is one of the best nightlights I have seen.
The one I have runs off 120vac but there may be 240vac versions. It draws only 1
watt of power yet emits more light than a standard 7 watt night light. I only
has an off-off switch and does not turn itself off during the day but it demands so
little power that such a feature would not be worth it. |
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| 10 Amp-hour NiMH D
Cells from Tenergy |
| When small AA
Rechargeable NiMH cells are too small for your battery power application, you might
consider a big D size battery. I don’t understand why American companies are not
cranking out larger rechargeable C and D size NiMH rechargeable batteries, but the 10
amp-hour D cells from Tenergy in China are just the ticket for higher power needs.
Their standard D cell size means you could use them in a wide variety of applications.
D cell battery holders are available in one to eight cell packs. A pack of 10
cells would yield a nice 12v battery. By using battery holders, you could
quickly replace those cells which become weak. NiMH batteries are great when you
need them to survive many deep charge/discharge cycles. |
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