walkman
Well Known Member
I want to use a transistor to switch an LED on and off that I'm dimming with a PWM dimmer.
I'll be using the +12v output of a toggle switch to drive the logic.
First question, will a regular PNP work or do or do I need a MOFSET or something.
I have 4 options total. Two regarding where the LED does, and two regarding where the PWM input vs logic switching input goes.
I'm using the LED's from MPJA with the dropping resistor built in. Does the LED (load) go on the collector or emitter side of the transistor?
Second, I can wire the +12v output side of the toggle switch to the base, and the PWM output to the collector, and use the toggle switch output to essentially switch the PWM output through. Or, I can wire the +12v toggle switch output to the collector, and the PWM output to the base. This option leaves the transistor "working" all the time, constantly switching the collector to emitter on and off with varying duty cycle based on dimmer position, except that most of the time the collector will be at 0.
Input solicited from those more electronic than I.
(Vern?
)
I'll be using the +12v output of a toggle switch to drive the logic.
First question, will a regular PNP work or do or do I need a MOFSET or something.
I have 4 options total. Two regarding where the LED does, and two regarding where the PWM input vs logic switching input goes.
I'm using the LED's from MPJA with the dropping resistor built in. Does the LED (load) go on the collector or emitter side of the transistor?
Second, I can wire the +12v output side of the toggle switch to the base, and the PWM output to the collector, and use the toggle switch output to essentially switch the PWM output through. Or, I can wire the +12v toggle switch output to the collector, and the PWM output to the base. This option leaves the transistor "working" all the time, constantly switching the collector to emitter on and off with varying duty cycle based on dimmer position, except that most of the time the collector will be at 0.
Input solicited from those more electronic than I.
(Vern?