40:
286:, also called vampire power if the device in standby is not doing anything useful such as being prepared to wake under timer control. Many meters only have a resolution of 1W when reading power; the Kill-a-Watts read down to 0.1W, but this is still too coarse for measuring low standby power. Modification to read standby power has been described and discussed in detail (with
28:
244:
One shortcoming of the Kill-a-Watt range of devices is that they do not have the ability to store, transmit or transfer the readings, thus limiting their usage for any ongoing monitoring purposes. To counter this shortcoming, a couple of openly available modifications have been published on the Web,
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The power setting displays instantaneous power, and the kilowatt-hour setting displays energy consumed since last reset. When electricity is disconnected, the P4400's measurements and meters are reset. To reset Kill A Watt models that store values, press Volt and Amp together, or press the Reset key
96:
receptacles, and a model compatible with 100 VAC for the
Japanese market (2022-04, marketed there as the Watt Checker Plus by other companies). The basic models support current up to 15 A, power up to 1,875 W (the 230 VAC equivalents also allow up to 15 A, corresponding to
202:
This is an enhanced version, based on the
Prodigit 2022, which includes a backup battery to store measurements even when disconnected from electricity. It has the same capabilities as the P4400, and can be programmed with electricity cost information, which enables it to display the cost of the
273:
chip known as the
Moteino, making this version much cheaper, and requires much less soldering than the original design. Further optimizations on the design were done by Mike Tranchemontage, his designs featured a more robust power supply unit to the moteino chip, avoid problems capacitors which
260:
chip, the creator was able to get readings for voltage and current and transmit to a computer, which then sent this to
Twitter via handle @tweetawatt. At the time it gained quite a lot of interest on the Web, but interest waned after some time. The last tweet from this handle was in March 2010.
294:, used to generate a voltage proportional to load current, is replaced by a much larger value, typically 100 times larger, with protective diodes. Readings of the modified meter have to be divided by the resistance factor (e.g. 100), and maximum measurable power is reduced by the same factor.
786:
The low power factor means that the DRSSTC was drawing awful peak currents, but the two meters still agreed well. I conclude that the
Prodigit wattmeter sold by Maplin works fine for Tesla coiling. It also seems to be fairly resistant to RFI, although I didn't let the coil arc to ground
83:
plug and receptacle, and rated for 115 VAC (maximum 125 VAC), the Kill A Watt is sold for the North
American market. The unit is manufactured by the Taiwanese company Prodigit, which also makes 230 VAC models of similar appearance and functionality for European
235:
Although identical externally, there have been several different versions of the Kill A Watt and
Prodigit equivalents, all essentially of the same design, but with different PCB layout, packaging, and components.
269:
Following the usefulness of the Tweet-a-Watt, designs for the WattMote were released on the Web by another hobbyist, Felix Rusu at LowPowerLab. The modifications use a customized clone of the
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shows voltage; current; true, reactive, and apparent power; power factor (for sinusoidal waveform); energy consumed in kWh; and hours connected. Some models display estimated cost.
546:
795:
745:
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manufactured by
Prodigit Electronics and sold by P3 International. It measures the energy used by devices plugged directly into the meter, as opposed to
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The Tweet-a-watt is a hacked version of the standard Kill-A-Watt Plug in Power Meter. By piggybacking on the device's on-board LM2902N
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This is the original, most basic version, based on the
Prodigit 2000M. From the time it is plugged in, it measures:
43:
Prodigit Model 2000MU (UK version), shown in use and displaying a reading of 10 Watts being consumed by the appliance
646:
69:
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219:, has a configurable overcurrent shutdown limit, and also measures earth leakage current; one version acts as an
215:. Unlike the other models, it does not display frequency or apparent power. It protects against surges and
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electricity consumed since reset. From this, it can calculate cost per hour, day, week, month, or year.
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This model, based on the
Prodigit 2024, is integrated into an eight-outlet
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Saving energy: is it better to start with utility bills or a Kill A Watt?
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17:
31:
This Kill A Watt model P4400 is displaying a current draw of 10.27
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532:, but informative technical description of the features provided.
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52:
543:"The Kill-a-Watt: Not all versions are created equal :)"
72:, which display the energy used by an entire household. The
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waveforms and measurements). Essentially, the meter's shunt
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to enable these devices send data wirelessly to a receiver.
353:"Kill A Watt Meter - Electricity Usage Monitor | P3"
332:
Edwin Kee (2008-05-26). "Cost-saving and handy devices".
594:"Tweet-a-Watt! A safe and simple wireless power monitor"
282:
Most plug-in wattmeters are not useful for measuring
519:
Power Safer — New Safety Revolution For Power Strip
793:The Latest Public Library Loan? Electricity Meters
647:"Meet the WattMote (Moteino based Tweet-A-Watt)"
274:discharged too slowly with the original design.
112:There are several models of Kill A Watt meters:
757:Kill A Watt EZ electricity usage monitor review
227:, minimizing current surges and interference.
223:(ELCB). It switches power on or off at an AC
748:Wireless communications added to Kill A Watt.
416:"Prodigit 2000M 8-in-1 Plug-in Power Monitor"
8:
731:P4400 Kill A Watt - official product website
569:"Kill A Watt P4400/P4460 circuit diagram"
100:The device can give an indication of the
347:
345:
343:
324:
741:Sparkfun: Cracking open a Kill A Watt
653:from the original on 15 December 2013
600:from the original on 17 November 2013
549:from the original on January 21, 2021
434:P4400 Kill A Watt TM Operation Manual
248:A circuit diagram has been drawn up.
7:
626:from the original on 7 November 2013
451:"Prodigit 2022 Energy Cost Monitor"
771:"Kill-A-Watt vs. analog wattmeter"
700:"Measuring standby power - Page 1"
476:"Prodigit 2024 8 Port Power Safer"
25:
400:"Gadgets that help save energy".
645:Rusu, Felix (28 December 2012).
710:from the original on 2020-10-21
674:"Moteino Kill-A-Watt: Hardware"
575:from the original on 2011-12-11
482:from the original on 2011-07-15
457:from the original on 2011-07-15
363:from the original on 2014-04-24
1:
221:earth leakage circuit breaker
769:Conner, Steve (2005-08-30).
309:Nonintrusive load monitoring
404:. 2008-05-04. pp. F02.
70:in-home energy use displays
836:
820:Electrical test equipment
620:"tweetawatt @tweetawatt"
509:Manufacturer's web site.
390:Manufacturer's web site.
672:Tranchemontagne, Mike.
357:www.p3international.com
44:
36:
42:
30:
500:P4320 Kill A Watt PS
207:P4320 Kill A Watt PS
198:P4460 Kill A Watt EZ
104:used by appliances.
680:on 14 December 2013
545:. August 22, 2011.
304:Home energy monitor
815:Electricity meters
798:2015-04-11 at the
762:2009-05-11 at the
736:Kill A Watt models
524:2009-04-21 at the
505:2009-04-16 at the
386:2011-07-15 at the
240:User modifications
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334:New Straits Times
16:(Redirected from
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97:3,750 W).
92:and Australian
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725:External links
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175:Apparent power
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159:Kilowatt-hours
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278:Standby power
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66:usage monitor
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35:in this mode.
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779:. Retrieved
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746:Tweet-a-watt
712:. Retrieved
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694:
682:. Retrieved
678:the original
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655:. Retrieved
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628:. Retrieved
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602:. Retrieved
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577:. Retrieved
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551:. Retrieved
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484:. Retrieved
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459:. Retrieved
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420:the original
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365:. Retrieved
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288:oscilloscope
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252:Tweet-a-watt
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189:Elapsed time
185:Power factor
179:Volt-amperes
119:
111:
99:
78:
56:
48:
46:
684:12 December
657:12 December
213:power strip
63:electricity
49:Kill A Watt
809:Categories
781:2009-07-16
775:Tesla Coil
714:2022-06-19
630:1 November
604:1 November
579:2014-04-29
486:2009-07-16
461:2009-07-16
367:2014-04-29
320:References
231:Variations
530:chinglish
439:(Report).
314:Wattmeter
165:Frequency
81:NEMA 5-15
79:Having a
18:Killawatt
796:Archived
787:heavily.
760:Archived
708:Archived
651:Archived
624:Archived
598:Archived
573:Archived
553:June 19,
547:Archived
522:Archived
503:Archived
480:Archived
455:Archived
384:Archived
361:Archived
298:See also
292:resistor
265:WattMote
61:) is an
58:kilowatt
271:Arduino
139:Amperes
135:Current
125:Voltage
94:AS 3112
90:BS 1363
88:, U.K.
33:Amperes
258:op-amp
157:Used (
155:Energy
108:Models
86:Schuko
437:(PDF)
169:Hertz
149:Watts
145:Power
129:Volts
116:P4400
686:2013
659:2013
632:2013
606:2013
555:2022
47:The
217:EMI
74:LCD
55:on
53:pun
51:(a
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342:^
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127:(
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
