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Required parts: 9V battery*, 1000 ohm resistor (brown black red ), red LED,
push-button
How it works:
pressed, a closed circuit is formed that makes the
current
flow
Current flows from the (+) of the battery to the
push-button, resistor, (+) of the LED and via the (-)
of the LED back to the battery.
Using a 1000ohm resistor the current will be about
0.007A (7mA).
Calculation of the resistor:
resistor = battery voltage – LED voltage
LED current
resistor = 9V - 1,8V = 1000ohm
0,007
www.vellemanprojects.com
As long as the push button is
and
the
LED
Time to experiment:
What happens when you swap (+) and (-) of the led?
What happens when you replace the 1000 ohm resistor
with a 100K ohm resistor (brown black yellow gold) ?
lights
up.
Pag. 11
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