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Topic: can I safely ground 12v (vcc) to digitalWrite(pin, LOW); (Read 340 times) previous topic - next topic

Wawa

Fairchiled TIP120 datasheet, Figure 2.
A TIP120 has a CE saturation voltage of ~0.6volt@1Amp, and ~1volt@3Amp.
Assuming a collector/base current ratio of 1:250.
Leo..

ReverseEMF

Fairchiled TIP120 datasheet, Figure 2.
A TIP120 has a CE saturation voltage of ~0.6volt@1Amp, and ~1volt@3Amp.
Assuming a collector/base current ratio of 1:250.
Leo..
That's if the transistor is running hot.  More like 0.8V at room temp.  But, you're right, for currents that low, the VCE(sat) is much lower than I stated.  But, we really don't know what current that solenoid is going to require, and since we haven't heard from the OP for a while, we may never know ;)
1.21 GIGAWATTS?!?

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