Archive for June, 2013
Video: Product Review
Video: Testing & Teardown
Links:
Product website CandelabraBulb.com or just search Amazon for Sexy LEDs
Another great YouTube channel that reviews LED blubs is ElectronUpdate’s YouTube channel
Features:
Candelabra bulb style in E12 sockets
4 Watt LED with 50 Watt equivalent light output 400 Lumens
Style is flame or round tip
Comes in gold or silver base
Dimmable
Life span is 12 years at 6.8hrs/day or 30,000 hours.
80% more efficient then incandescent
Soft, warm white light (2700 k)
Hidden heat sink
Return on Investment:
5 watt x 6 hours per day usage x 365 days = 10.95 kWh.
At 12 cents per kWh it will cost $1.32 a year to operate.
Subtract that from the $10.50 cost to run a 40 watt bulb saves you $9 per yr.
I have 16 bulbs so I will save $144 per year.
The current cost for 16 bulbs is ~$416 so I would get 100% ROI in 2.8 years.
Photo Gallery
CLICK PHOTO for gallery view and click a SECOND time for hi-resolution image. Click thumbnails on lower right and lower left of gallery to navigate gallery photos.
- Sexy LED for review and teardown
- One Sexy LED full on
- One Sexy LED dimmed to lowest setting
- Marking on packaging
- Current test
- 1 minute trend on current shows 74 mA
- Zoom in on current trend to see small ripple.
- Current average was 74 mA
- 120V x 0.074A give 8.76 watts. Higher than advertised 5 watts!
- K type temperature probe on metal heat sync to read operating temperature.
- Used in my hall for 3 months. Look very nice!
- Probing operating temperature.
- operating temperature trend started
- operating temperature trend finished.
- K type temperature probe set to read operating temperature of glass bulb
- operating temperature of glass bulb is 51.6C
- Close up of the six LEDs once glass is removed.
- Setup to read operating temperature of LED substrate
- operating temperature of LED substrate was 71.5C after 10 minutes.
- operating temperature of LED substrate trend plot.
- Thermal conductive pad between LED substrate metal and metal heat sync.
- Removing the electronics package
- Some kind of SMPS circuit
- power circuit
- power circuit with large cap and transistor removed
- power circuit
- power circuit
- power circuit
- Large Cap
- Transformer
- LEDs See datasheet for LEMWH51W80MZ30_5152
- LEDs See datasheet for LEMWH51W80MZ30_5152
- LED substrate
- LED substrate
- LED top view
- Testing just LEDs using bench power supply
- Testing just LEDs using bench power supply. Ran at 18A 300 mA but normal light output was 15V 40 mA
- Thanks for joining!
This is 2 part of the TENMA 72-7745 multimeter product review. (Link to Part 1).
Here I cover the poor but usable PC logging software. Then I spend some time on evaluating the battery performance before a complete teardown. In the teardown I found that the PCB is actually for a UNI-T UT60E. If you want to know as much as possible about this meter or the UNI-T UT60E for that matter then check out the specifications listed in part 1 and watch both videos.
http://www.newark.com/tenma/72-7745/multimeter-digital-handheld-3-3/dp/02J5542
$54.49 promo sale, normal $90.45
Microprocessor used: FS9721_LP3
http://www.datasheets360.com/pdf/6170317308701690972?comp=3143&query=fs9721
Learn everything you need to know about good multimeter input protection:
EEVblog #373 – Multimeter Input Protection Tutorial
Photo Gallery
CLICK PHOTO for gallery view and click a SECOND time for hi-resolution image. Click thumbnails on lower right and lower left of gallery to navigate gallery photos.
In this 2 part product review I examine in detail all the features and performance of the TENMA 72-7745 multi-meter. Part 1 is an intro with a full feature and performance review excluding the PC software and battery performance, which are in part 2. Also in part 2 is a complete teardown where I find that the PCB is actually for a UNI-T UT60E.
If you want to know as much as possible about this meter or the UNI-T UT60E for that matter then check out the below specifications and the two videos.
http://www.newark.com/tenma/72-7745/multimeter-digital-handheld-3-3/dp/02J5542
$54.49 promo sale, normal $90.45
The price has went up to $64 but that is still a great price for a meter with these features that includes PC data logging. The temperature probe and the meter probes where very poor but once replaced the meter performed quite well and I was very happy with this multimeter.
Weekly radio podcast on electronics.
Dave Jones’s EEVBlog electronics tutorials and product reviews.
Battery Capacity Tutorial
http://www.eevblog.com/2011/01/23/eevblog-140-battery-capacity-tutorial/
MJ Lorton YouTube channel for lots of multi-meter reviews
https://www.youtube.com/user/mjlorton
Doug’s Voltage Standard site where he sales the PentaRef and DMM Check Plus
http://www.voltagestandard.com/
TENMA 72-7745 (UNI-T UT60E) Specifications:
Auto ranging: yes
Manual ranging option: yes (but not in capacitance mode)
Meter count: 4000 counts
True RMS: yes
DC volts: 400mV ±0.8%+3, 4/40/400V ±0.8%+1, 1000V ±1.0%+3
AC volts: 4/40/400V ±1.0%+5, 750V ±1.2%+5
DC amps: 400/4000µA ±1%+2, 40/400mA ±1.2%+3, 4/10A ±1.5%+5
AC amps: 400/4000µA ±1.5%+5, 40/400mA ±2%+5,4/10A ±2.5%+5
DC + AC measurement mode: no
Resistance: 400Ω ±1.2%+2, 4k/40k/400k ±1.0%+2, 4M ±1.2%+2, 40MΩ ±1.5%+2
Conductivity: no
Diode test: yes (1.48v)
Continuity test: yes (not latched but fast)
Capacitance: 40nF ±3%+10, 400nF/4/40µF ±3%+5, 100µF ±4%+5
Frequency: 10Hz – 10MHz (< 30v rms) (5Hz-400Hz on V/A switch range)
Duty cycle: 10Hz – 10MHz (< 30v rms) (5Hz-400Hz on V/A switch range)
Temperature: yes (Celsius only) -40C to 1000C
Min/Max options: no
Data hold: yes (not auto, have to press hold button)
Relative mode: yes (only auto ranges in Cap mode)
Automatic power off (APO): no
Overload protection: yes (not the best, I say CAT II or lower only!)
Input Impedance for DC Voltage ~10M ohms
Battery life: ~250 hours
Battery low indication: yes (< 3.6v)
Powered: 9v battery
Fuse protected: yes (All ranges uA, mA and A)
PC interface connection: yes (rs232 optical linked)
PC data logging software: yes (very