Name: 做一個緊急電話充電器--MacGyver風格! (Make an Emergency Phone Charger - MacGyver Style!)
Uploaded: 2021-01-14T07:04:49.000Z
Duration: 6 min 1 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

There's no charge for this electricity. In
this project we're making a 40 watt hand cranked

generator from these common household items.

For this project, let's see if we can make
an emergency cellphone charger out of a cordless

drill. I have a USB charger that charges this phone from a USB port, and we don't really

need the USB head, so let's go ahead and cut
that off, then use some wire strippers to

remove this outer layer. The shielding can
be pulled back, revealing the 4 wires inside.

I've done this to both ends of the cable,
and stripped the plastic from the ends of

the wires. Most phone batteries need around
5 volts to charge, and we can confirm that

by plugging the USB head into the port, and
attaching some alligator clips to the red

and black wires. Using a multi-meter, you
can see just over 5 volts of direct current.

With the phone in series, the circuit is completed
when these wires touch and the phone senses

power and lights up. This little black plug
symbol shows that it's charging, and it only

appears when the phone gets around 5 volts.
Ok, Let's build our make-shift phone charger.

I have a cordless drill I think I can convert
into an electrical generator by running it

backwards. I'll remove the bit, take the battery
out, and looking up into the handle, you can

see the two terminals where the battery would
connect. For testing, I'll attach alligator

clips to both of them, and then connect the
leads to my multi-meter. When I pull the trigger

and twist the rotating end of the drill I'm
generating around 5 volts, and that's what

we need. To make this into an emergency cell
phone charger, let's round up a piece of scrap

2x4, a wooden fork, a ball of yarn, a mixing
beater, a roll of tape, and some aluminum

foil. The first thing we'll need to do is
secure the trigger in the "on" position. It

won't work unless this button is fully pressed,
so let's use plenty of yarn to secure that,

then fasten the drill to the 2x4 with as many
wraps as it takes to hold it tight. The mixing

beater gets inserted into the drill chuck,
and when it's fastened in tight we can double

check there's no slack when it rotates.
We'll need the torque setting to be at it's

highest, and confirm the drill is set to reverse.
Now it's time to rig the electrical system.

Let's rip this sheet of aluminum foil in 2
strips, then fold them into makeshift wires.

You can use copper wire if you have it, but
aluminum is still a good conductor, and this

foil will work in a pinch. These ends are
being rolled to a point, and these other ends

folded over to make them a little thicker.
Now the flat ends can be held in place under

the terminal clips of the drill, and since
we made these wires so long, let's use the

extra length to make sure they're well separated
because they'll short out if they touch. A

little tape will hold those temporarily, until
we can add some yarn to fasten them in place.

The red and black wires are stripped down
about an inch, and for this phone, we don't

need these wires at all. So one cut and they're
gone. Now the red and black wires are attached

to the aluminum leads, respecting the polarity
of the drill. In this case, red is our positive,

and the black is our negative. The wires are
secured with some more yarn, and all we need

now is some leverage for our crank handle.
My wife's salad fork will work, and now that

we've got our handle, I'm thinking this is
ready for a test. I'll start cranking to see

what happens, and look at that, the phone
lit right up. It's showing the little plug

symbol, so we know this is charging, and if
I stop, the symbol goes away. It looks like

it's working great, so I'm gonna take this
inside and clamp it down to a table for better

leverage. The crank handle gets inserted,
and the system is powered up. The charging

symbol is flashing which means I need to crank
just a little bit faster for stable power.

And there it is. I'm cranking this at about
100 RPM to develop the 5 volts this phone

needs to charge. If I crank slower, the phone
won't power up, and if I crank too fast, I

risk damaging it. Just for the challenge,
I'm going to see how long it takes to re-charge

this battery from its completely discharged
condition. It seems to be taking quite a while,

but when I think about it, it takes quite
a while even when it's plugged in with a charger.

I'm coming up on 3 hours, and I just saw the
charging symbol flash off. That means this

battery isn't accepting any more charge. It's
done. I can disconnect the charger cable and

this phone is fully ready to go. If this electrical
generator will charge a phone, I'm wondering

if it will recharge a battery. I've added
metal magnets to the ends of a rechargeable

AA battery, so that my alligator clips will
attach easily. By attaching the same wire

to both ends, we've shorted it out, and the
charge is being drained as quickly as possible,

and I can feel the battery getting hot. This
battery is completely dead now, so to revive

it, I'm adding these lead wires in parallel
with the system, and connecting them to their

respective terminals. It takes about 15 minutes
of cranking, and it's harder to turn the handle

this time, because I'm pushing a larger electrical
current into the battery. Alright, it's done,

and a quick test on the meter shows that the
battery is fully charged. Well that was educational.

I tried shorting the system out on my meter,
and got about 6 volts at 7 amps. That's over

40 watts of power. I also tried hooking up
an incandescent flashlight bulb, and got it

to fully illuminate. A white LED was also
tested, and was so bright it actually hurt

my eyes to watch. Well there's a makeshift
electrical generator that you can make in

a pinch, that will charge batteries, illuminate
lights, and generate around 40 watts on human

If you liked this project, perhaps you'll
like some of my others. Check them out at