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Sat 2021.05.15
from post #1
re: 'By the way the MDBT42 stop crashing if I add two big capacitors'While I don't have that hardware to test, It is likely that:
As a motor is inductive and requires an initial massive draw to get going, that after the caps charged, there was sufficient current to start the motor turning. A coin cell isn't designed for high current spikes. see spec p.1 'Standard Continuous Discharge Current 0.3 mA'
re: 'but the MDBT42 crashes'
As E = I x R as current draw goes up, voltage goes down. It is likely that battery voltage fell too low for the MDBT42Q to operate.I agree with @AkosLukacs at around ~260mAhr a CR2032 coin cell wont last that long
https://www.duracell.com/wp-content/uploads/2016/03/CR2032JCS0820.pdf
Robin
Hi everyone,
I have a circuit with a PuckJS, a motor driver and a motor DC powered by the same CR2032 battery. I would like to replace the PuckJS with an MDBT42 but the MDBT42 crashes when the motor is powered. Everything works fine with PuckJS.
Does anyone know why ?
By the way the MDBT42 stop crashing if I add two big capacitors (1000uF 25V), one at board terminal, one at the battery terminal. But those capacitors are too big for the space I've got. I tried with smaller capacitors or just one but it doesn't work. I can't get why.
The motor draws 10-25mA.
Thanks a lot