I am trying to drive a 1W LED from 4 1.2V NiCd cells. My intent is to cut off the power to the LED when the battery falls below 4.2 V and light up a RED LED to let everyone know that the batteries need to be recharged.
My circuit is attached. Please let me know what am I doing incorrectly.
The transistor Q1 is driving the 1W LED well by pumping around 200mA of current, but when the transistor Q1 cuts-off I hope that at that point Q2 would turn on, thus lighting up the RED LED. Am I missing something?
The latter part does not seem to work.
Any help is greatly appreciated.
-AM
My circuit is attached. Please let me know what am I doing incorrectly.
The transistor Q1 is driving the 1W LED well by pumping around 200mA of current, but when the transistor Q1 cuts-off I hope that at that point Q2 would turn on, thus lighting up the RED LED. Am I missing something?
The latter part does not seem to work.
Any help is greatly appreciated.
-AM
Attachments
-
5.5 KB Views: 59