using a capacitor/diode to keep presets?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=33695
Printed Date: May 28, 2024 at 11:10 PM
Topic: using a capacitor/diode to keep presets?
Posted By: southpawboston
Subject: using a capacitor/diode to keep presets?
Date Posted: June 11, 2004 at 3:22 PM
i have to disconnect my battery a lot to work on the car, and i hate having to constantly re-program all my head unit's settings each time.
i'm thinking of hooking up a capacitor and a diode to the const. 12V lead. very little current runs through it since it only powers the memory. could i just hook up a standard 1N4001 1A diode, followed by a small capacitor inline with the constant memory lead? the capacitor would hold a small charge to feed the memory (couple of milliamps probably), while the diode would prevent the capacitor from discharging back through the car's electrical system. it almost seems too easy. am i correct in this design? what value (in µF) would you recommend for the capacitor to give me about 1 hour of memory backup?
Replies:
Posted By: southpawboston
Date Posted: June 11, 2004 at 3:24 PM
almost forgot: sequence would be 12V-->diode-->capacitor-->HU
Posted By: xetmes
Date Posted: June 11, 2004 at 3:26 PM
it would work, but the capacitor would have to be large, bigger than uF... check out this thread.. https://www.the12volt.com/installbay/forum_posts.asp?tid=22462&KW=battery+backup
Posted By: DYohn
Date Posted: June 11, 2004 at 3:34 PM
You'd be better off looking for a head unit that has non-volitile memory... a capacitor in place of the backup battery would not provide much capacity. ------------- Support the12volt.com
Posted By: sandt38
Date Posted: June 11, 2004 at 10:14 PM
Buy a memory saver. Any tool truck will have one, and likely most part stores. All it is is a 9 volt battery connector attatched to a lighter plug. Plug it into the lighter and it will keep your juice without issue.
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Posted By: auex
Date Posted: June 11, 2004 at 10:25 PM
Does anyone know what size cap is needed to keep a cva 1005 on during cranking? That is a good question and is probably not enough to keep your memory for an hour.
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