Darlington TIP120 transistor switches

Sunflower

I am not clear on the data of switching transistors..

Are the Bases of Darlingtons pulled to ground internally?

Should I pull Stamp pins to ground when using NPN common and high-gain transistors?

How should I calculate the TIP120 Base to Stamp pin resistor? (hfe 1000 at 3 V.) (solenoid valve 12 V. 500 ma. plus spike?) Would 220 ohms cover the bases?

The data says Base max current is 120 ma. How could that happen?

I read that IN4004 snubbing diode is added to the TIP120. Is this necessary?
(I also read that the heat sink tab is grounded to the Collector.)

Newzed

Treat the TIP120 just like the 2803, except put a 1K resistor in series with the base of the transistor.· That all there is to it.

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Sid Weaver
Do you have a Stamp Tester?

http://hometown.aol.com/newzed/index.html
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Sunflower

That is so easy, thanks!