1
00:00:00,170 --> 00:00:04,400
One of my favorite things in life is when
I discover an unexpected piece of technology

2
00:00:04,400 --> 00:00:06,770
in everyday household items.

3
00:00:06,770 --> 00:00:10,830
Many of us have so many interesting things
around us that may go unnoticed.

4
00:00:10,830 --> 00:00:12,700
Take kitchen appliances, for example.

5
00:00:12,700 --> 00:00:17,400
They’re often a lot simpler than at first
they seem, but in at least one particular case,

6
00:00:17,400 --> 00:00:21,000
that simplicity is accomplished with
wondrous ingenuity.

7
00:00:21,000 --> 00:00:23,340
I’m talking, of course, about toasters.

8
00:00:23,340 --> 00:00:26,910
Yes, the toaster, perhaps the silliest household
appliance.

9
00:00:26,910 --> 00:00:31,160
A single-purpose receptacle in which you place
sliced carbohydrate media to be partially

10
00:00:31,160 --> 00:00:32,980
burned for your enjoyment.

11
00:00:32,980 --> 00:00:34,300
Delicious.

12
00:00:34,300 --> 00:00:38,240
Electric toasters have come a long way from
their 19th century roots--

13
00:00:38,240 --> 00:00:40,180
good grief that’s terrifying--

14
00:00:40,180 --> 00:00:42,379
wonder no more when the toast
will pop up.

15
00:00:42,379 --> 00:00:47,469
The jumpscare potential has been completely
eliminated with this digital display.

16
00:00:47,469 --> 00:00:49,299
And wanna toast more than bread?

17
00:00:49,299 --> 00:00:50,539
What about a bagel?

18
00:00:50,539 --> 00:00:55,559
Be amazed as the side elements turn off, toasting
only the cut side.

19
00:00:55,559 --> 00:00:57,219
Innovation at work!

20
00:00:57,219 --> 00:01:01,429
Of course, if you actually go back a mere
70 years in time, you’ll discover a toaster

21
00:01:01,429 --> 00:01:04,920
that is better than modern toasters in nearly
every single way.

22
00:01:04,920 --> 00:01:07,729
You’re right, sally, it is like magic.

23
00:01:07,729 --> 00:01:11,740
But ignoring the surprising backward steps
we seem to have made in the tantalizing territory

24
00:01:11,740 --> 00:01:15,350
of toaster technology, let’s get to the
point of this video, shall we?

25
00:01:15,350 --> 00:01:18,460
This toaster was a mere $8.88.

26
00:01:18,460 --> 00:01:20,800
That’s only $4.44 per slice!

27
00:01:20,810 --> 00:01:25,659
Now, perhaps it’s not surprising to you
that a toaster can be manufactured so cheaply.

28
00:01:25,659 --> 00:01:28,920
It is after all simply a small box with a
bit of nichrome wire

29
00:01:28,920 --> 00:01:31,040
(that’s an alloy of nickel and chromium)

30
00:01:31,040 --> 00:01:33,710
forming bread-singeing
heating elements.

31
00:01:33,710 --> 00:01:35,039
How complicated can it be?

32
00:01:35,039 --> 00:01:37,960
All it has to do is turn on the heating elements for a while,

33
00:01:37,960 --> 00:01:40,710
then shut them off and lift the bread.

34
00:01:40,710 --> 00:01:44,939
Ah, but see, it’s the way the simplicity
is accomplished that’s so ingenious.

35
00:01:44,939 --> 00:01:49,479
First, have you ever tried to push the lever
down while a toaster is unplugged?

36
00:01:49,479 --> 00:01:53,219
If you do, you’ll notice that it simply
won’t stay down.

37
00:01:53,219 --> 00:01:57,399
No matter how hard you force it, the lever
simply springs back up.

38
00:01:57,399 --> 00:01:58,399
Why is that?

39
00:01:58,399 --> 00:02:02,600
Well, it turns out that this single lever
is performing the roles of bread lowering

40
00:02:02,600 --> 00:02:07,689
and lifting mechanism, power button, switch
contact, retention latch, circuit breaker,

41
00:02:07,689 --> 00:02:11,840
and thing-that-moves-the-little-bread-squeezing--centering-things-in-and-out.

42
00:02:11,840 --> 00:02:15,930
Uh, to explain how it does all those things,
we’ll need to take this apart.

43
00:02:15,930 --> 00:02:20,909
And through the magic of buying two of them,
I have an already-taken-apart one right here.

44
00:02:20,909 --> 00:02:24,890
Under the plastic covering is a sheet metal
box containing the heating elements, as well

45
00:02:24,890 --> 00:02:27,159
as a small circuit board.

46
00:02:27,159 --> 00:02:30,640
This circuit board doesn’t do all that much,
but the way it has been integrated into the

47
00:02:30,640 --> 00:02:33,600
device as a whole is simply fascinating.

48
00:02:33,600 --> 00:02:35,900
First, notice these two pairs of contacts.

49
00:02:35,900 --> 00:02:38,629
These are what actually provide power to the
toaster.

50
00:02:38,629 --> 00:02:41,620
In this state, there is no completed circuit.

51
00:02:41,620 --> 00:02:46,080
If you look at where the power comes in on
the board, it goes right to this contact,

52
00:02:46,080 --> 00:02:48,340
and then it’s got nowhere to go.

53
00:02:48,340 --> 00:02:51,500
This contact must be pushed down to complete
the circuit.

54
00:02:51,500 --> 00:02:55,600
Actually both pairs of contacts must be, as
the other one breaks the connection on the

55
00:02:55,610 --> 00:03:00,480
neutral side as well, a smart move to protect
against the potential for a power outlet with

56
00:03:00,480 --> 00:03:02,440
the hot and neutral wires reversed.

57
00:03:02,440 --> 00:03:05,960
If, when it’s plugged in, I manually engage
the contacts using these

58
00:03:05,960 --> 00:03:10,080
high-tech insulated poking devices, now power can flow through the toaster.

59
00:03:10,090 --> 00:03:13,770
You’ll hear a slight buzz and see that the
heating elements begin to glow.

60
00:03:13,770 --> 00:03:15,440
[buzzing of toaster]

61
00:03:15,440 --> 00:03:19,640
Not only do the elements
receive power, but so does the rest of the board.

62
00:03:19,640 --> 00:03:23,280
But what is responsible for normally engaging
those contacts?

63
00:03:23,280 --> 00:03:25,840
Why, the lever of course.

64
00:03:25,840 --> 00:03:28,700
Also, I’ve just realized this isn’t technically
a lever.

65
00:03:28,700 --> 00:03:29,900
Why do we call it a lever?

66
00:03:30,540 --> 00:03:33,420
Wait, do we call it a lever?

67
00:03:33,420 --> 00:03:35,720
Let’s double-check that Sunbeam ad.

68
00:03:36,460 --> 00:03:37,900
Yeah, lever.

69
00:03:38,360 --> 00:03:39,080
Hmm.

70
00:03:40,180 --> 00:03:43,720
Anyway when the lever reaches the bottom,
a set of its own insulated poking devices

71
00:03:43,720 --> 00:03:46,950
press the contacts down, and thus complete
the circuit.

72
00:03:46,950 --> 00:03:50,019
That’s not the interesting part, though,
ho no.

73
00:03:50,019 --> 00:03:52,680
The interesting part is how it stays down.

74
00:03:52,680 --> 00:03:57,180
Remember, with the toaster unplugged, the
lever refuses to stay in the down position.

75
00:03:58,960 --> 00:04:00,760
It just pops right back up.

76
00:04:00,769 --> 00:04:03,469
But with it plugged in, now it will.

77
00:04:03,469 --> 00:04:04,599
How?

78
00:04:04,600 --> 00:04:06,940
Well, watch closely.

79
00:04:13,920 --> 00:04:17,280
Did you see that metal plate suddenly stick
to the yellow thing?

80
00:04:17,280 --> 00:04:18,350
Watch again.

81
00:04:18,350 --> 00:04:21,660
That yellow thing is an electromagnet, and
so long as it has power,

82
00:04:21,660 --> 00:04:25,240
it will hold the lever in place which keeps the contacts pushed in

83
00:04:25,240 --> 00:04:28,100
and allows power to flow through the heating elements.

84
00:04:28,100 --> 00:04:31,360
Now you may have already figured out the double
whammy of genius here.

85
00:04:31,360 --> 00:04:35,730
If the only thing holding the lever down is
an electromagnet, and the only way the toaster

86
00:04:35,730 --> 00:04:40,320
will work is with the lever held down, then
by shutting off the electromagnet, it will

87
00:04:40,320 --> 00:04:45,160
let go of the spring-loaded lever, shut off
the power, and of course eject the bread,

88
00:04:45,160 --> 00:04:48,320
now toast, in a violent fashion without warning.

89
00:04:48,320 --> 00:04:49,370
Fascinating.

90
00:04:49,370 --> 00:04:51,470
Which brings us to the other stuff on the
circuit board.

91
00:04:51,470 --> 00:04:55,550
Though we don’t need much in the way of
circuitry in here, we do need a way to determine

92
00:04:55,550 --> 00:04:59,860
how long to hold down the lever, and thus
how long to toast the bread.

93
00:04:59,860 --> 00:05:02,660
These days it’s handled with specialized
components, like this

94
00:05:02,660 --> 00:05:07,160
(in a high-pitched, altered voice)
“MULTIPLE FURNACE DISABILITIES TIMING IC”,

95
00:05:07,160 --> 00:05:11,930
which features
such marvels as CMOS, TO-94, and Bagel.

96
00:05:11,930 --> 00:05:15,720
Google Translate wasn’t much help here,
but in any case we do know this is suitable

97
00:05:15,720 --> 00:05:21,470
for all types of toaster, and it appears to
support a bagel mode but I can’t see exactly

98
00:05:21,470 --> 00:05:26,770
how the chip itself is going to handle a bagel
mode given that it only has the one output.

99
00:05:26,770 --> 00:05:30,600
In any case, the main thing this chip is doing
is looking at the output from the potentiometer

100
00:05:30,600 --> 00:05:33,580
here to determine how long to stay on.

101
00:05:33,580 --> 00:05:39,300
And as we know from the datasheet, roast the
development of the time interval: 0-300 seconds.

102
00:05:39,300 --> 00:05:44,320
Also, let’s just get it out of the way that
these numbers do not correspond to minutes.

103
00:05:44,320 --> 00:05:47,990
Tom Scott already did a video on this, but
this should give you further proof because

104
00:05:47,990 --> 00:05:55,180
if the max time is 300 seconds, that’s 5
minutes, not 6, so these are just arbitrary numbers.

105
00:05:55,180 --> 00:05:59,560
And funnily enough the box suggests there
are only 6 settings, when in reality there

106
00:05:59,560 --> 00:06:06,250
are probably 300, as this is not a 6-position
switch, it is an infinitely variable potentiometer.

107
00:06:06,250 --> 00:06:07,250
But I digress.

108
00:06:07,250 --> 00:06:10,900
Anyway, most of the other stuff on the board
is support equipment for the main IC, such

109
00:06:10,900 --> 00:06:15,580
as its power regulator and smoothing capacitors,
though surprisingly there is a diode connected

110
00:06:15,580 --> 00:06:18,880
straight up to this yellow lead going into
the toaster body.

111
00:06:18,880 --> 00:06:22,690
This might be designed to halve the available
current to part of the element through half-wave

112
00:06:22,690 --> 00:06:27,030
rectification, and indeed the middle section
doesn’t glow as intensely as the outermost

113
00:06:27,030 --> 00:06:31,530
sections so perhaps that connects to the middle
section, but I can’t say for sure.

114
00:06:31,530 --> 00:06:35,500
If I’m following my traces right, the actual
electromagnet is connected to this little

115
00:06:35,500 --> 00:06:39,561
transistor on the bottom, which is itself
connected to the output of the main IC we

116
00:06:39,561 --> 00:06:40,740
were looking at earlier.

117
00:06:40,740 --> 00:06:45,750
So, the IC is in control of the electromagnet
and when it decides the toast is done, it

118
00:06:45,750 --> 00:06:49,560
kills the output to the transistor, which
kills the power to the electromagnet, which

119
00:06:49,560 --> 00:06:51,320
kills the power to the everything.

120
00:06:51,320 --> 00:06:55,300
Oh, and this little switch here, activated
by turning the darkness dial all the way to

121
00:06:55,300 --> 00:06:59,440
the left, will interrupt power to the electromagnet
and immediately release the toast.

122
00:07:00,780 --> 00:07:04,200
There’s a bit of a poetic sadness to the
way this circuit works.

123
00:07:04,200 --> 00:07:07,220
When you press the lever down, it comes to
life and says “Oh!

124
00:07:07,220 --> 00:07:08,220
Hello world!

125
00:07:08,220 --> 00:07:11,180
Let’s see, first I’ve got to send power
out on pin 1.

126
00:07:11,180 --> 00:07:16,430
It looks like I’m getting 2.4 volts in on
pin 3 so I’ll just count to 137.”

127
00:07:16,430 --> 00:07:19,680
And then 137 seconds pass and it says “Time’s
up!

128
00:07:19,680 --> 00:07:22,060
Now I’ll just stop sending power out on
pin 1 and…”

129
00:07:24,300 --> 00:07:29,060
Before we were putting self-aware digital
circuits in toasters, mindless analog circuits

130
00:07:29,060 --> 00:07:31,800
would do the same thing but more crudely.

131
00:07:31,800 --> 00:07:35,250
Often the timing was accomplished through
charging a capacitor, and the setting of the

132
00:07:35,250 --> 00:07:40,760
darkness dial, being a potentiometer, would
change the rate at which this capacitor was charged.

133
00:07:40,760 --> 00:07:44,940
Once it’s past a certain voltage level,
the power gets cut to the electromagnet via

134
00:07:44,950 --> 00:07:48,210
a transistor, and pop goes weasel.

135
00:07:48,210 --> 00:07:51,470
And before that, a simple mechanical clock
timer would suffice.

136
00:07:51,470 --> 00:07:56,200
And I haven’t even gotten into this complication;
some toasters use more than just time, or

137
00:07:56,200 --> 00:07:57,870
don’t use time at all!

138
00:07:57,870 --> 00:08:01,270
Sometimes there’s a bimetallic thermostat
near where the bread sits, and adjusting the

139
00:08:01,270 --> 00:08:05,270
darkness adjust the temperature at which the
thermostat would open the contacts.

140
00:08:05,270 --> 00:08:06,860
No timer required.

141
00:08:06,860 --> 00:08:10,790
Newer toasters with digital circuits can use
use a thermocouple to determine if the toaster

142
00:08:10,790 --> 00:08:16,900
is cold and thus if it will need more time
for the first toast, and less time for subsequent ones.

143
00:08:16,900 --> 00:08:22,080
The sky’s the limit when it comes to today’s
totally technical temperature-tied toaster technology.

144
00:08:22,080 --> 00:08:25,540
In fact, if you’re looking for something
to read, check out the description for a patent

145
00:08:25,540 --> 00:08:29,860
on time-based temperature compensation circuits
from 1982!

146
00:08:29,860 --> 00:08:34,620
This design uses a second capacitor that is
charged up fully whenever the toaster is used,

147
00:08:34,620 --> 00:08:38,579
and slowly discharges after the toaster has
finished toasting.

148
00:08:38,579 --> 00:08:43,349
If the toaster is immediately used again,
it won’t have discharged much at all.

149
00:08:43,349 --> 00:08:48,720
The charge on this secondary capacitor effectively
gets transferred into the main timing capacitor

150
00:08:48,720 --> 00:08:51,120
and thus will shorten the overall toasting
time,

151
00:08:51,120 --> 00:08:54,339
helping to compensate for an already-hot toaster.

152
00:08:54,339 --> 00:08:58,720
If it hasn’t been used in a while, the capacitor
will be fully discharged, and thus the toaster

153
00:08:58,720 --> 00:09:00,810
runs for the normal period of time.

154
00:09:00,810 --> 00:09:05,829
You may have spotted the “chip with temperature
compensation” earlier, so even our $8.88

155
00:09:05,829 --> 00:09:09,110
toasters probably have a similar hot-toaster-taming-timer.

156
00:09:09,110 --> 00:09:12,699
If anyone wants to look at this schematic
and reverse engineer how it could do that,

157
00:09:12,699 --> 00:09:17,040
be my guest, but I’ll throw my supposition
into the ring and suggest that the chip probably

158
00:09:17,040 --> 00:09:21,960
can stay awake for a while between toasts
thanks to energy stored in one of these capacitors,

159
00:09:21,960 --> 00:09:25,120
and thus can keep track of how long it’s
been between toasting sessions.

160
00:09:25,120 --> 00:09:27,560
Anywho, I think I’ve had enough toast for
one day.

161
00:09:28,280 --> 00:09:29,880
Actually, I don’t even really like toast.

162
00:09:29,889 --> 00:09:33,230
I haven’t used my toaster in close to a
year.

163
00:09:33,230 --> 00:09:37,629
In fact, I’m pretty sure the last time I
used it was to hold up the multi-colored flashlights

164
00:09:37,629 --> 00:09:41,040
in the “these are not pixels revisited”
video.

165
00:09:41,040 --> 00:09:42,040
Yikes.

166
00:09:42,040 --> 00:09:45,879
And of course, I’d like to raise a toast
to the wonderful people on Patreon who keep

167
00:09:45,880 --> 00:09:48,740
these videos and my terrible puns coming.

168
00:09:51,180 --> 00:09:56,060
With the support of people like you, Technology
Connections is about to see a pretty major upgrade.

169
00:09:56,060 --> 00:09:59,480
I’ll fill you in on the details pretty soon
but for now, if you’d like to support the

170
00:09:59,490 --> 00:10:03,360
channel with a pledge of your own and get
perks like early video access, occasional

171
00:10:03,360 --> 00:10:07,649
behind-the-scenes footage, as well as find
out what that upgrade is I’m talking about,

172
00:10:07,649 --> 00:10:09,610
please check out my Patreon page.

173
00:10:09,610 --> 00:10:12,100
Thanks for your consideration, and I’ll
see you next time!

174
00:10:12,660 --> 00:10:14,660
♫ toasty smooth jazz ♫

175
00:10:16,800 --> 00:10:21,839
And, through the magic of buying two of them,
I have an already taken apart one, right here!

176
00:10:21,839 --> 00:10:24,949
(cord hits the microphone) That went really
badly!

177
00:10:24,949 --> 00:10:27,340
Often the timing was accomplished through
charging a capacitor.

178
00:10:27,340 --> 00:10:28,580
[toaster pops up]

179
00:10:30,740 --> 00:10:33,460
So it definitely is temperature
compensated.

180
00:10:33,460 --> 00:10:35,160
We figured that one out.

181
00:10:37,340 --> 00:10:38,420
Before we were putting self...

182
00:10:38,420 --> 00:10:39,140
[toaster pops
up]

183
00:10:39,140 --> 00:10:40,620
(bleep) it’s that fast!

184
00:10:41,180 --> 00:10:45,380
Ah, but see it’s the way that simplicity
is accomplished that’s so ingenious.

185
00:10:45,380 --> 00:10:49,460
First, have you ever tried to push the lever
down while the heater is unp….

186
00:10:49,460 --> 00:10:50,480
Toaster….

187
00:10:50,520 --> 00:10:54,459
Often timing was accomplished through charging
a capacitor, and the setting of the darkness

188
00:10:54,460 --> 00:10:58,420
dial, being a potentiometer [toast pops up],
would change the rate…

189
00:10:58,420 --> 00:10:59,180
Yeah I shoulda known…