Data Sheet
-95-
192. Capacitor Polarity
Build the circuit shown on the left and turn on the switch (62). Press
the press switch (61) and you will see the colorful LED (72) light and the
alarm (78) will sound. Release the press switch (61) and the colorful
LED (72) will stay bright for a while then turn dim and the alarm (78)
will stay on for a while then turn off.
The capacitors in your set have polarity, just like the LEDs. If you look
closely at the capacitor in your 470mF capacitor (74), you will see a
white band marked with a “–” sign along the side of them. This indicates
that the 470mF capacitor (74) should always be placed in the circuit so
that lower voltage in on the “–” side of the 470mF capacitor (74), like
in this circuit.
193. Capacitor Voltage Rating
Replace the 470mF capacitor (74) in project #192 with the 100mF
capacitor (73) and turn on the switch (62). Press the press switch
(61) and you will see the colorful LED (72) light and the alarm (78) will
sound. Release the press switch (61) and colorful LED (72) will stay
bright briey and then turn dim and the alarm (78) will sound briey
and then go off.
If you look closely at the 100mF capacitor (73) you will see that it has
a voltage rating of 10V on the side. This capacitor should not be used
in any circuit that could product more than 10V across it. The battery
module (91) only provides 4.5V (and at most 5V with brand new
batteries) so there is no need to worry about ever going above 10V with
the components in this set.
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