A
[email protected]
- Jan 1, 1970
- 0
Hi all.
I built (on a breadboard) the following circuit for my first
electronics project:
http://www.mightyatom.com/elec/LED_dimmer.pdf
Note that the parallel resistor array (R4-R8) is there simply because I
ran out of 1K resistors.
It works, generally; rotating the pot controls the brightness. However,
I note that the LED never actually goes out, it just gets fairly dim.
When I test the duty cycle across the LED with my DMM at the minimum, I
get 1.8% (99% at maximum).
Can anyone suggest a change that would allow me the full range of
brightness from off to bright?
Also, removing one of the resistors from the parallel array (thereby
raising the resistance of the array as a whole) brightens the LED. Can
anyone explain why? (I'm clearly just getting started with all this.)
Thanks for helping a newbie.
/afb
I built (on a breadboard) the following circuit for my first
electronics project:
http://www.mightyatom.com/elec/LED_dimmer.pdf
Note that the parallel resistor array (R4-R8) is there simply because I
ran out of 1K resistors.
It works, generally; rotating the pot controls the brightness. However,
I note that the LED never actually goes out, it just gets fairly dim.
When I test the duty cycle across the LED with my DMM at the minimum, I
get 1.8% (99% at maximum).
Can anyone suggest a change that would allow me the full range of
brightness from off to bright?
Also, removing one of the resistors from the parallel array (thereby
raising the resistance of the array as a whole) brightens the LED. Can
anyone explain why? (I'm clearly just getting started with all this.)
Thanks for helping a newbie.
/afb