I would like to design a voltage regulator that essentially duplicates the function of the old electro-mechanical regulators but I do not understand how I can predict or control the differential between the steps. I would like to drive two relays with the output - primarily because the users would like it that way (they understand "zero charge" or "half charge rate").
The charge states are "no charge", "half charge" and "full charge" as it describes the amount of charge being applied by the generator.
I would like "no charge" at 7.4 volts, "half charge" at 7.2 volts" and "full charge" at 7.0 volts and less. The problem: as the battery charges it crosses the 7.0 volt point (or 7.2 or 7.4) and if there is not enough differential or hysterisis then the system will be unstable and might just toggle or oscillate back and forth.
I would like to know how I can design something with a predictable (and preferably adjustable) differential in order to avoid this instability. Example: if the voltage is well below 7.0 volts the system will be at full charge and as voltage rises past 7.0 volts the system will switch to half charge. In some cases the voltage may drop ever so slightly on this changeover and I don't want it to go back to full charge - I'd rather it be 6.9 volts. I know there is differential or hysterisis in most systems but I'd like to be able to predict what it is and adjust it somewhat if possible. Does anyone know how to do this??
This seems like a perfect fit for a microcontroller but I have not progressed enough yet with my learning to actually design something. I'd also like to understand how to control or predict the differential for other applications.
Thanks.
The charge states are "no charge", "half charge" and "full charge" as it describes the amount of charge being applied by the generator.
I would like "no charge" at 7.4 volts, "half charge" at 7.2 volts" and "full charge" at 7.0 volts and less. The problem: as the battery charges it crosses the 7.0 volt point (or 7.2 or 7.4) and if there is not enough differential or hysterisis then the system will be unstable and might just toggle or oscillate back and forth.
I would like to know how I can design something with a predictable (and preferably adjustable) differential in order to avoid this instability. Example: if the voltage is well below 7.0 volts the system will be at full charge and as voltage rises past 7.0 volts the system will switch to half charge. In some cases the voltage may drop ever so slightly on this changeover and I don't want it to go back to full charge - I'd rather it be 6.9 volts. I know there is differential or hysterisis in most systems but I'd like to be able to predict what it is and adjust it somewhat if possible. Does anyone know how to do this??
This seems like a perfect fit for a microcontroller but I have not progressed enough yet with my learning to actually design something. I'd also like to understand how to control or predict the differential for other applications.
Thanks.