START
Daily Sprint
1.What is Ohm’s Law?
2.A circuit is measured and has a voltage
of 6.04v and current of 0.0004A. What is
the total resistance in the circuit?
3.What is a capacitor? (make a prediction)
MSA Prep
Solve:
4 x 3 +2 x 5 – 6 ÷ 2 + 32
Capacitors
Capacitors
• Capacitors
• Charging the Capacitor
• Discharging the Capacitor
This presentation is intended to be used with Activity 4.2.5 Capacitors.
Capacitors
Capacitor: An electrical device used to
store electrical charge
Symbol for Circuit
Diagrams
Capacitors
Capacitors allow DC
current to flow through a
circuit as they fill with a
charge.
_
DC
+
When the capacitor’s
voltage supply matches
the power source,
current stops flowing.
Capacitors
• Stored energy in the capacitor is released in a quick burst
unless slowed by resistance.
• Capacitors are found in almost all electronic devices.
– They store energy, provide quick bursts of power, even out power
if there is a small loss, etc.
• Capacitors are used for the flash in cameras.
Charging the Capacitor
Gather a 12V power source, a lamp, and a
4700uF capacitor. Leave a spot for the capacitor
but do not attach it yet.
_
DC
+
You may need to wire more than one power source in the
circuit in order to reach 12V.
Just as an LED is polarity-sensitive, many capacitors are
too. Look for an indication on the capacitor to verify.
Charging the Capacitor
Plug in the capacitor.
_
DC
+
What did the LED do after the
capacitor was plugged in?
Discharging the Capacitor
Build a circuit with a pushbutton switch, a 6V /
.5A (or higher) lamp, and a place for the charged
capacitor to be placed.
Will the polarity of the capacitor affect this circuit?
Explain.
Discharging the Capacitor
Plug in the capacitor.
What did the lamp do?
Conclusion Questions
1.
Describe something other than the
examples you’ve been given that you
believe uses a capacitor and its function in
the device.
2.
What do capacitors have to do with the
dangers of older television sets?
Image Resources
Microsoft, Inc. (2009). Clip Art. Retrieved January 22, 2009, from
http://office.microsoft.com/en-us/clipart/default.aspx