Re: Will this circuit work?
Nice to hear some experience. I have only ever used supercaps with a rear light.
How about connecting the mid-point of the caps to the midpoint of the leds and not needing the resistors.
And isomax, not all GoldCaps are the same.
Some have high internal impedance so charge and discharge slowly - 'uA' types
others have low internal impedance so charge and discharge quickly - 'A' types
and there are 'mA' types in the middle
see www.panasonic.com/industrial/components/capacitive/cap_gold.htm
It is mostly the same for other super-cap brands.
Does anyone want 4 (or 5) component circuit that will charge your super cap quickly, and control the current into the bottom led? It will waste 5mA (1%)
If you stay at 20mA in standby, you will get a dim light, but it will be last for a predictable and useful time.
I would draw it and scan it now, but I can't remember how to post pictures here.
Steve
....If you want an even better standlight use two gold caps in series in place of the smoothing capacitor.....If you do this you should use some voltage balancing resistors (10K ohms or so) across each goldcap to make sure the caps discharge fully overnight, this will prevent the caps from charging unevenly.
Nice to hear some experience. I have only ever used supercaps with a rear light.
How about connecting the mid-point of the caps to the midpoint of the leds and not needing the resistors.
And isomax, not all GoldCaps are the same.
Some have high internal impedance so charge and discharge slowly - 'uA' types
others have low internal impedance so charge and discharge quickly - 'A' types
and there are 'mA' types in the middle
see www.panasonic.com/industrial/components/capacitive/cap_gold.htm
It is mostly the same for other super-cap brands.
Does anyone want 4 (or 5) component circuit that will charge your super cap quickly, and control the current into the bottom led? It will waste 5mA (1%)
If you stay at 20mA in standby, you will get a dim light, but it will be last for a predictable and useful time.
I would draw it and scan it now, but I can't remember how to post pictures here.
Steve
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