How to determine when a hot glue gun is ready based on power draw?

Hardware
1

I’m making my hot glue gun a bit smarter by plugging it into a ESPHome-ified smart plug with power monitoring.

The hot glue gun has a variable temperature setting (dial), and presumably a thermostat.

I thought I should be able to determine when the hot glue gun is ready to use based on power/current?

The power seems to initially spike, and then taper down to a steady value.

Would anyone with knowledge of how these heating devices usually work have any thoughts on how I might infer when it’s ready from it’s power draw signature?

The gun states it will be ready in 3-5min, but it seems to come down to it’s steady state power draw after only about 1-2mins.

Here’s a plot of power. Red line indicates when the hot glue gun was on.

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(Edit: actually I measured time to steady state a bit more accurately, and it seems to be in range of stated heating times. So I think this is my answer. Ready when Power is below around 26 watts for say 20sec).

2

Actually when I was doing those initial tests, I had it on maximum temp, and it looks like it maintains that base power draw to keep it at that level.

But when set to a lower than max temp level, you get something more like I was expecting. A classic thermostat looking on/off to keep it in a temp range after it’s reached it’s target temp. Should be able to work with that.

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