Electronics

This is an old trick to save batteries from draining when you don’t have an on/off switch and don’t want to take out your batteries between usages.

Plus I take a few current measurements to show the current usage is ~200uA when not used for charging. This stand-by current is just to power the circuit when not being used.

An on/off switch would have prevented this ~200uA stand-by current but would have complicated the build and increased the product price. So slipping in a bit of paper between two batteries or an end connector does just the same as a switch. This trick brings the stand-by current to 0A and the batteries are good even a year later instead of being dead.

Yes, taking the batteries out works and is better but is more difficult and you have to find your batteries when you need to use your MintyBoost.

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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.

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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

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