Problem with constant dc supply by capacitor

[Apache]

I have a problem
how can i obtain a constant value of dc voltage from a capacitor(dynamo) to supply a device..
As we know if the capacitor is directly connected to the device, the voltage will drop and the device will not have enough voltage to function.
what is a better way?

 

[Simon Bridge]

voltage regulator.

 

[nsaspook]

5vdc boost regulator example: http://www.bodhilabs.com/vpackbareaaa.html

 

[berkeman]

I have a problem
how can i obtain a constant value of dc voltage from a capacitor(dynamo) to supply a device..
As we know if the capacitor is directly connected to the device, the voltage will drop and the device will not have enough voltage to function.
what is a better way?

Or you can use a SEPIC DC-DC converter, which would allow you to have the capacitor voltage initially above the output regulated voltage, and as the capacitor discharges, its output voltage can fall below the output regulated voltage:

http://en.wikipedia.org/wiki/Single-ended_primary-inductor_converter

.

 

[Simon Bridge]

@Apache: any of this help at all?

 

[Apache]

Yup, I have fix a voltage regulator in my circuit, thanks!