Hi all,
I've a CarPC installed in my car and it's powered from the cars' 12v so it's a simple setup. However, after turning off the ignition, I want to power the PC for a further 5 minutes for the purpose of being able to make quick stops (like a petrol fillup) without having to shut the PC down. I have installed a Turbo Timer which looks after the countdown but I have a problem with a momentary loss of power between the ignition Off and the Timer power On.
I think my best bet is a capacitor to just bridge the potential 0.5 second (or less) gap - but what size of capacitor do I need ? The voltage is obviously about 12v (since the engine and alternator will be off at this point). The PC (a thin client model) could be pulling up to 3A. I bought a 16v 4700uf cap but once I connected it to the feed supply 12v wire, at the minus leg of the cap, it only measured just over 4v.
So do I need three of them ? In series or in parallel ? Or something else ?
I've a CarPC installed in my car and it's powered from the cars' 12v so it's a simple setup. However, after turning off the ignition, I want to power the PC for a further 5 minutes for the purpose of being able to make quick stops (like a petrol fillup) without having to shut the PC down. I have installed a Turbo Timer which looks after the countdown but I have a problem with a momentary loss of power between the ignition Off and the Timer power On.
I think my best bet is a capacitor to just bridge the potential 0.5 second (or less) gap - but what size of capacitor do I need ? The voltage is obviously about 12v (since the engine and alternator will be off at this point). The PC (a thin client model) could be pulling up to 3A. I bought a 16v 4700uf cap but once I connected it to the feed supply 12v wire, at the minus leg of the cap, it only measured just over 4v.
So do I need three of them ? In series or in parallel ? Or something else ?