pbilous Member Joined 2011 Paid Member 2022-03-30 9:15 am #61 2022-03-30 9:15 am #61 I think I figured it out. Attached is the model that includes all three LEDs in series. Running it in spice showed acceptably small current ripple on each LED - from 8.7mA to 10.5mA. Turn off delay should be short too - because of 47uf cap. Attachments delay-2n3904.asc delay-2n3904.asc 2.1 KB · Views: 88 sch-2.PNG 8.4 KB · Views: 163 sch-r1.3.PNG 25.8 KB · Views: 161 Mooly Moderator Joined 2007 Paid Member 2022-03-30 9:48 am #62 2022-03-30 9:48 am #62 You have 70ma but it is an AC quantity and very spiky in nature. The rms value is just 24 milliamps giving approximately 60 milliwatts dissipation. Attachments Screenshot 2022-03-30 094126.jpg 301.3 KB · Views: 110 Prev 1 2 3 4 First Prev 4 of 4 Go to page Go You must log in or register to reply here.
I think I figured it out. Attached is the model that includes all three LEDs in series. Running it in spice showed acceptably small current ripple on each LED - from 8.7mA to 10.5mA. Turn off delay should be short too - because of 47uf cap.
Mooly Moderator Joined 2007 Paid Member 2022-03-30 9:48 am #62 2022-03-30 9:48 am #62 You have 70ma but it is an AC quantity and very spiky in nature. The rms value is just 24 milliamps giving approximately 60 milliwatts dissipation. Attachments Screenshot 2022-03-30 094126.jpg 301.3 KB · Views: 110
You have 70ma but it is an AC quantity and very spiky in nature. The rms value is just 24 milliamps giving approximately 60 milliwatts dissipation.
