Article View: sci.electronics
Article #17680Re: info on clocks using battery backups
From: fish
Date: Fri, 19 Jun 1987 21:22
Date: Fri, 19 Jun 1987 21:22
17 lines
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1366 bytes
In article <3622@cisunx.UUCP>, nf165636@cisunx.UUCP writes: > > How do the clocks (and clock radios) that run on main power (110/60 Hz) > count the time ? Especially those that use battery backups. In this case > do they use a quartz crystal ? Does that mean that these can be used > on 110/50 Hz or any other frequency ? Any info will be appreciated. Most cheap digital clocks and clock radios with battery backup use the line frequency as a primary time base, and have an internal oscillator as the backup. The oscillator is not crystal-controlled, and will drift considerably, causing the clock to lose or gain several minutes in a day. However, they are usually accurate enough to maintain the correct time during brief power outages. -- __ / \ Bob Fishell \__/ ihnp4!ihlpa!fish
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!ihlpa!fish From: fish@ihlpa.UUCP Newsgroups: sci.electronics,misc.consumers Subject: Re: info on clocks using battery backups Message-ID: <4323@ihlpa.ATT.COM> Date: Fri, 19-Jun-87 17:22:23 EDT Article-I.D.: ihlpa.4323 Posted: Fri Jun 19 17:22:23 1987 Date-Received: Fri, 26-Jun-87 01:53:32 EDT References: <3622@cisunx.UUCP> Organization: AT&T Bell Laboratories - Naperville, Illinois Lines: 17 Summary: Battery backups not accurate