MP3Car.com - View Single Post - Anyone want to help me with the tank battery

Ricky327 · 06-09-2004, 01:20 PM

Curiosity

Your idea can work if I picture it correctly from your descriptions. Basically the relay will switch over from main to backup battery when you crank?

As you are already aware the relay switching from main to backup can have problem. That split second the relay switching over may cause your PC to reboot or crash. True a capacitor will help the situations but then thats just making things complicated...a big capacitor is not cheap thought, they are quite bulky. I cant see it not working but the solutions is not cheap.

UPDATE :

I do agree with the zero voltage drop concept, as you said it is ideal. I have posted a zero voltage drop circuit before...basically its based on diodes as well as relay switching over from main to battery as you crank.

The diodes are there so the PSU doesnt loose the supply completely as the relay switches over. The diodes keep the voltage into the PSU at full amount at any time (less the 0.3-0.7V drop of course). Once the relay switches over then thats when theres no voltage drop at all since it shorts the diode.

As you can see the diodes are only at work for split second...so hardly any heat is generated. The resistor is placed that way so full amount of charging voltage always enter the tank battery...as well as it serve as a current limit.

I have to post all over again as I couldnt find the zero voltage drop tank circuit I posted months and months ago.

06-09-2004, 01:20 PM	#14
Ricky327 Raw Wave Join Date: Jun 2003 Location: London UK Vehicle: 1992 Ford XR2i Posts: 1,818 My Photos: ()	Curiosity Your idea can work if I picture it correctly from your descriptions. Basically the relay will switch over from main to backup battery when you crank? As you are already aware the relay switching from main to backup can have problem. That split second the relay switching over may cause your PC to reboot or crash. True a capacitor will help the situations but then thats just making things complicated...a big capacitor is not cheap thought, they are quite bulky. I cant see it not working but the solutions is not cheap. UPDATE : I do agree with the zero voltage drop concept, as you said it is ideal. I have posted a zero voltage drop circuit before...basically its based on diodes as well as relay switching over from main to battery as you crank. The diodes are there so the PSU doesnt loose the supply completely as the relay switches over. The diodes keep the voltage into the PSU at full amount at any time (less the 0.3-0.7V drop of course). Once the relay switches over then thats when theres no voltage drop at all since it shorts the diode. As you can see the diodes are only at work for split second...so hardly any heat is generated. The resistor is placed that way so full amount of charging voltage always enter the tank battery...as well as it serve as a current limit. I have to post all over again as I couldnt find the zero voltage drop tank circuit I posted months and months ago. Attached Images Last edited by Ricky327 : 06-09-2004 at 02:00 PM.