Transistor as switch, power saving from switching current source?

Thread Starter

Thecomedian

Joined Oct 12, 2013
22
https://learn.sparkfun.com/tutorials/transistors/applications-i-switches

Are there any complications from making the resistance as high as possible to limit power consumption from the control source? I can make an identical circuit and put 50k into R(b), receiving a negligible current loss for the LED/I(CE), and greatly improving the power consumption for the switching control source.

Is the gain of the transistor a factor in using a transistor as a switch?
 

crutschow

Joined Mar 14, 2008
23,296
Yes, the transistor gain is a factor. Good engineering practice is to use a base current no lower than 1/10th of the collector current to fully turn on a BJT transistor.
If you want a lower control current than that, you could use a MOSFET which requires zero gate current to turn on.
 
Top