How to circuit several caps to one powersupply

[morten]

For a batterybackup for a burglar alarm I would like to use supercaps. The alarm runs 12 V and the supercaps are around 5 V max. I would like to ask if some one knows a simple way to konnect 2 or 3 supercaps so that they get charged (each only with nominal V) by the powersupply from the alarm (12 V), and so that if the power fails, they are connected in serie and give the combined V to the alarm?

I am a hobbyist :???:

Morten

 

[kam1787]

maybe best to arrange a resistor divider to ensure each cap is charged at the rate set by the resistors

 

[morten]

Hi Kam.

Thanks for your answer. I would think that solution uses a lot of power. But with resistors big enough, thats ok. But how do I circuit 3 supercaps so that no to large current occurs or overvoltage? I have thought of using zener diodes in stead of resistor divider?

Morten

 

[kam1787]

why worry about high current or over-voltage? is your power supply that bad?

I think you worry too much, but if it keeps you from sleeping, then put in a proper power supply

 

[GUMY]

Just put 3 caps in series.

 

[Pha5e]

You'd be better off using a Sealed Lead Acid battery (SLA) as it will be able to deliver the power required by the panel in the event of power failure. Supercaps will most likely not be able to supply the required power for a sustainable period. Remember the panel backup battery also has to be able to charge a backup battery in the siren and possibly power it too if sounding.

On another thread you mention using lead acid batteries:

https://www.edaboard.com/threads/293918/

 

[tpetar]

For a batterybackup for a burglar alarm I would like to use supercaps. The alarm runs 12 V and the supercaps are around 5 V max. I would like to ask if some one knows a simple way to konnect 2 or 3 supercaps so that they get charged (each only with nominal V) by the powersupply from the alarm (12 V), and so that if the power fails, they are connected in serie and give the combined V to the alarm?

I am a hobbyist :???:

Morten

You cannot replace battery with supercapacitor for this role. Supercaps cant keep electricity on longer time, lets say tomorrow will be empty. For now is that situation, but we will see what they cooking in labs for newer supercapacitors.

Best battery backup is another battery, which is dedicated only for that purpose. :smile:


Best regards,
Peter

:wink: