HELP My Final Year Project.. Switchover backup and charging.

[dhorl]

Hello all..

I'm really a newbies in this electronic design world.. now i'm going to design a project that supposely to switchover to a battery backup in case of PSupply(5V regulated DC) failure. Mm.. the idea is to switch and then later charging the battery(PP3-9v NiCd) if the supply is back... The battery is label with 150mAhwith standard charge 16Hrs at 15mA... now i'm confuse to design the rechargeable circuitry.. what voltage and current should I use... Can anybody design for me the schematics.. your help is highly appreciated..

Best regards..

DhorL Jr'
dhorl@yahoo.com

 

[mesteru]

Schematic1

 

[john1]

Hi dhorl,

Best of luck designing your battery back-up system.
What did you think of the schematic that mesteru sent?

John

 

[Sebi]

The circuit is correct,but in D5 position i recommend also a schottky diode for smaller lost from batt.

 

[dhorl]

Huhu..

hello all expert..

I think ok,.. i also receive some shchematic by mail.. thank guys out there who willing to lend me a hand Well.. now I'm worry about, let say the supply down, the battery switch to backup.. what about if the supply go on again.. i'm thinking of having some sort of charging circuit also for my 9v Nicd pp3 battery.. any idea?

 

[dhorl]

Explanatin please...

LOL..

I see the circuit.. impress me much.. but can anybody explain how it work... automatic switch isn't? Mmm.... and what the value of capacitor and also inductor...

 

[mesteru]

S1.rar it is with value of all capacitor C1,C2..... and also inductor iron.
But you must wait for „Power Supply Control and Battery Charger Control” schematics.
Mmm.. isn’t there any explanation for this circuit Sir..
Maybe you tell me how it works!
OK

 

[dhorl]

Thanks mate..

Hye masteru...

Thanks pal.. o i c ,, the circuit is not completed yet, :roll: Anyway, i do have this IC MAX713 for NiCd charger control.. can it be used.. Well, I got to complete it very soon, what ur idea of battery and power supply control so that i can help also to figure it out.. hope so

 

[mesteru]

The MAX713 it's a fast-charge Nickel Metal Hydride (NiMH) and Nickel Cadmium (NiCd) batteries, and you want a normal-charge Nickel Cadmium (NiCd) batteries

 

[dhorl]

Masteru..

D4 and D5 is missing.. is that you wanna replace with switch.. mm can't we use some sort of relay like when supplyy off change top the battery.. and then after battery voltage decrease its voltage to certain limit, it will begin rechagre and then stop when it is full? An idea... from a beginner..