2n2222 question

[strokedmaro]

Would a 2n2222 be able to safely operate 2 of these 5vdc relays? If Im reading the 2n2222 datasheet correctly, it says the collector current (DC) or "Ic" is max 800 mA....that would mean I could roughly use a single 2n2222 to switch 10 of these relays at 72 mA a piece??? Does not seem right or is it? Attached is a pic of the coil data for the relays Im trying to operate...an omron G5V-2-H. THANKS!

If Im totally wrong, please let me know what Im looking for so I know in the future...THANKS AGAIN!!

 

[bananasiong]

Hi,
Can you elaborate more?
i think if you're driving the transistor with 720 mA I think it's okay. But as the collector current gets higher, Vce is increased too. So the voltage across the load is not 5 V anymore.
How many relays are you going to drive? From a microcontroller?

 

[mneary]

Although Ic max is 800 ma, you can see on the data sheet that the 2N2222 is almost useless even at 150mA (two relays). The gain falls off rapidly long before the max current is reached. The much more popular 2N2222A should drive two relays. It will need 15mA of base current to do this.