- #1
phlegmy
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Hey guys
i'm putting together a shopping list for my first microcontroller project.
One thing i need is a slotted photoswitch (to count rotations of an anometer)
The project will be powered by a 9v battery, regulated to 5v.
The photoswitch has an led on one "post" and the other post has a photo transistor to detect the light from the led.
The switch I'm looking at has a this data sheet
http://www.farnell.com/datasheets/9111.pdf
and the product is here:
http://ie.farnell.com/optek-technology/opb610/opto-switch-slotted/dp/1497899
I'm finding some info a bit difficult to interperut
On page 2, it says the reverse input voltage is 3v (drop across the led on input post?)
with a forward dc current of 50mA
This means i need a resistor in series of (5-3)/.05 = 40ohms? for the input led
CONFUSION:
It also says that the collector-emmiter voltage is 24V with a collector-emitter current of
30mA,
this is what confuses me. i have no idea if i can just hook up the collector to the 5v supply and connect the emmiter to ground through a resistor, and measure the output on the switch side of the resistor?i suppose i could just buy one and see if it will work, but words of wisdom at this stage would save me some troubel and potentially some €'s!
i'm putting together a shopping list for my first microcontroller project.
One thing i need is a slotted photoswitch (to count rotations of an anometer)
The project will be powered by a 9v battery, regulated to 5v.
The photoswitch has an led on one "post" and the other post has a photo transistor to detect the light from the led.
The switch I'm looking at has a this data sheet
http://www.farnell.com/datasheets/9111.pdf
and the product is here:
http://ie.farnell.com/optek-technology/opb610/opto-switch-slotted/dp/1497899
I'm finding some info a bit difficult to interperut
On page 2, it says the reverse input voltage is 3v (drop across the led on input post?)
with a forward dc current of 50mA
This means i need a resistor in series of (5-3)/.05 = 40ohms? for the input led
CONFUSION:
It also says that the collector-emmiter voltage is 24V with a collector-emitter current of
30mA,
this is what confuses me. i have no idea if i can just hook up the collector to the 5v supply and connect the emmiter to ground through a resistor, and measure the output on the switch side of the resistor?i suppose i could just buy one and see if it will work, but words of wisdom at this stage would save me some troubel and potentially some €'s!
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