Can anyone help I want to fix a led. into the charging circuit of my battery operated screw driver. The charging system is only 3.5 V. I want to see if the charging system is working at a glance, the led is red and do I to fit a resistor in the circuit and if so what rating ? Also should the led be connected in series or in parallel.

thanks,
mike. [email protected]

 

A Led typically drops 1.5 V and a good nominal current is 20 ma. So with 2 V remaining a 100 ohm resistor would give you about 20 ma.

Regards
cww

 

thanks ccw for the info should the led be wired in series.

regards,
mike...............

 

Yes, observe polarity on the led.

Regards
cww