Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Help selecting transistor

Status
Not open for further replies.

R2-D2

Member
I don't know if such exists...

I'm looking for an NPN transistor with a collector current of about 150mA when saturated at 5mA to its base (β = 30). The collector voltage needs to be 12V when 8V applied to its base.
It also needs to handle a current increase of 15mA to its base via a selector switch.

Thanks
Jeff
 
Last edited:
I don't know if such exists...

I'm looking for an NPN transistor with a collector current of about 150mA when saturated at 5mA to its base (β = 30). The collector voltage needs to be 12V when 8V applied to its base.
It also needs to handle a current increase of 15mA to its base via a selector switch.

Thanks
Jeff
8 volts from base to emitter will destroy a transistor.
 
Hi Ron,

Thanks for the response.
I forgot to consider that there will be a resister applied directly to its base which drops majority of the voltage to it for safe operation. I think a 2N3904G would do for what I need according to its specs but not sure:

Collector Emitter Saturation Voltage, Vce(sat):0.3V
Power Dissipation, Pd:0.625W
DC Current Gain Min (hfe):40
C-E Breakdown Voltage:40V
Collector Current:0.2A

Datasheet:
https://www.electro-tech-online.com/custompdfs/2009/01/2N3903-DPDF.pdf

Jeff
 
I would use PN2222A. Most BJTs specify saturation voltage with forced beta=10, which means Ib=Ic/10. With Ic=150mA and Ib=5mA (forced beta=30), it will almost certainly work, but saturation voltage is not guaranteed.
 
Good morning Ron,

Thank you for that link to the data sheet.
The PN2222A looks good - I'll definitely try that one out.

Happy New Years! :)
Jeff
 
Status
Not open for further replies.

New Articles From Microcontroller Tips

Back
Top