Can someone help me work out total amp draw for LEDs with an in-series resistor?
I am getting conflicting answers depending on where I look.
- One way tells me the amp draw is the total amp draw of all LEDs combined, same as supply voltage.
- Another way seems to indicate that the total amp draw is singular, as in 3 LEDs with an in-series resistor (each LED being 20mA) will still only be 20mA.
12v + ---->|---->|---->|---///---- -
LED = Vf3.8/If20mA
R = 33ohms
Would the amp draw be 20mA or 60mA?
Further on from that, for multiple chains like that running from the same source, EG, 20 chains in parallel of x3 LEDs (each with in-series resistor), 400mA or 1.2A?
Hopefully I have explained my question right, but probably got some vernacular wrong, so I apologise in advance.
PS: Apologies for the Resistor not showing correctly, having trouble getting the ASCII to display correctly