Archive for June, 2013

Video: Product Review

 

Video: Testing & Teardown

 

Links:

LED datasheet

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.

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.

http://www.theamphour.com/

 

Dave Jones’s EEVBlog electronics tutorials and product reviews.

http://www.eevblog.com/

 

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