6 volt down to 3.5 volt dc

[tommylee]

Can anyone tell me how to reduce a 6volt lantern battery down to 3.5 volt for a led light?
Thanks

 

[MikeMl]

A single resistor will do it. How many mA is the LED rated for? How bright do you want it?

 

[Mosaic]

Check spec. for LED Vf , eg 2V
Check spec for continuous forward current eg. If=20mA.
Calc 6-2 =4V
Calc 4/.020 = 200Ohms.

Use a resistor in the 220 Ohm to 330 Ohm range based on brightness desired (smaller is brighter)

 

[tommylee]

Mike it is a 20ma and voltage is 3.2 thru 3.8 as fare as brightness I dont care, as bright as it turns out will be fine. thanks for your help.

 

[tommylee]

Mosaic, so a 220 to 330 wouldd get me in range of 3.2 to 3.8 volt ?? Its a 20ma LED

 

[alec_t]

so a 220 to 330 wouldd get me in range of 3.2 to 3.8 volt ??

You don't set the voltage; you set the current (by choice of resistor) knowing Vbattery and the Vf range, as Mosaic explained. 220 will be fine in this case.