Trying to understand ESP32 GPIO triggering relay based on AdaFruit Latching Circuit

Electronics student here, new to simulation and trying to learn using Adafruit's latching relay schematic ( and could use some help.

My goal is to build my own ESP32 controller on a custom PCB that can trigger both 5v and 3v relays. Starting with this 3v latching relay schematic, ESP32 datasheet says 40 mA source current on the high level and -28 mA sink current on the low level for the GPIO pins that will be driving the transistors. I modeled the Adafruit in CL and note that the current flowing through the 2222 is over 50ma to trigger the relay coil and light the LED. My first question is: Is it OK to drive the LED with that much current?

by DDomnick
September 01, 2021

Am I reading that wrong:? I suppose the collector current of Q1 is the sum of the relay current and the LED current. If I look at the LED cathode, it shows -1.520ma. That's too low it seems.

by DDomnick
September 01, 2021

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