I'm trying to get a dynamo-run headlight/taillight pair up and running. I've got a test circuit working on a little bottle dynamo, but I'd like to get feedback on it (i.e. will this blow up and spray battery acid on me?) before committing it to a circuit board.
The basic idea is this: I have a rectifier that that goes straight to some power LEDs (nothing fancy) on the headlight, and then, in series with that circuit, I run the following schematic as a blinky light for the rear. The little X1 set of terminal is just run in series with the front LEDs. That is, the positive terminal of the rectifier leads to X1:1, and the X1:2 leads to the positive terminal of the next white LED. Assume that the transistor, capacitor and resistor values are appropriate (I didn't include the front light in the schematic because I'm really slow at making schematics).
I found initially when I ran this without the battery that it would cause the front to pulse in time with the blinking in the back. Then I hooked up the battery (3xAAA Ni-MH, because that's what I had) in parallel with this and it made the pulsing in the front go away and also made a nice blinky stand lamp (bonus!). **Obviously, this guess and check method of testing should not be tried by anyone**
I ran it for a few seconds just on a bottle dynamo in my truing stand and it worked beautifully - is there anything dangerous or stupid about this setup that will fail if I run it on a bike?
LEDs are Luxeon K2 red emitters (Vf typical = 2.95).
EDIT: I should mention, without the dynamo aspect of this, this is a pretty standard blinky circuit. I was inspired by this: http://www.instructables.com/id/Two-transistor-LED-Flasher-Circuit/step3/Circuit-Diagram/
The idea is that, rather than having one light blink and disrupt the entire circuit by drawing, and then not drawing, power, it has two lights that light in sequence (when one is off, the other is on), so that the power draw is more or less constant for the circuit, as a whole.
The basic idea is this: I have a rectifier that that goes straight to some power LEDs (nothing fancy) on the headlight, and then, in series with that circuit, I run the following schematic as a blinky light for the rear. The little X1 set of terminal is just run in series with the front LEDs. That is, the positive terminal of the rectifier leads to X1:1, and the X1:2 leads to the positive terminal of the next white LED. Assume that the transistor, capacitor and resistor values are appropriate (I didn't include the front light in the schematic because I'm really slow at making schematics).
I found initially when I ran this without the battery that it would cause the front to pulse in time with the blinking in the back. Then I hooked up the battery (3xAAA Ni-MH, because that's what I had) in parallel with this and it made the pulsing in the front go away and also made a nice blinky stand lamp (bonus!). **Obviously, this guess and check method of testing should not be tried by anyone**
I ran it for a few seconds just on a bottle dynamo in my truing stand and it worked beautifully - is there anything dangerous or stupid about this setup that will fail if I run it on a bike?
LEDs are Luxeon K2 red emitters (Vf typical = 2.95).
EDIT: I should mention, without the dynamo aspect of this, this is a pretty standard blinky circuit. I was inspired by this: http://www.instructables.com/id/Two-transistor-LED-Flasher-Circuit/step3/Circuit-Diagram/
The idea is that, rather than having one light blink and disrupt the entire circuit by drawing, and then not drawing, power, it has two lights that light in sequence (when one is off, the other is on), so that the power draw is more or less constant for the circuit, as a whole.
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