Thanks in large part to Bill_Marsden's comprehensive guides to the 555, I have finally come to understand how to set up a 1/10 duty cycle with a Tm of 1ms.
However, this brings out another oddity that I am having trouble wrapping my head around:
Driving several LEDs with a 555, without using current limiting resistors, I expected to see a total current draw of ~300mA in my circuit.
LEDs are 2.6 Vf, 30 mA If units, wired in parallel, driven with a 2N5088 transistor. Without limit resistors, I expected to see a lot higher total current than just 30mA for the entire circuit.
What gives? I think I understand that the It (how do you do subscripts?) will be an average, but still, shouldn't the circuit draw a lot more than this? I don't have access to a wigglescope [oscilloscope] to see the actual peak instantaneous draw when the output is high.
Can anyone give me a clue here?
However, this brings out another oddity that I am having trouble wrapping my head around:
Driving several LEDs with a 555, without using current limiting resistors, I expected to see a total current draw of ~300mA in my circuit.
LEDs are 2.6 Vf, 30 mA If units, wired in parallel, driven with a 2N5088 transistor. Without limit resistors, I expected to see a lot higher total current than just 30mA for the entire circuit.
What gives? I think I understand that the It (how do you do subscripts?) will be an average, but still, shouldn't the circuit draw a lot more than this? I don't have access to a wigglescope [oscilloscope] to see the actual peak instantaneous draw when the output is high.
Can anyone give me a clue here?