Path: csiph.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Kallu Wiegand Newsgroups: comp.sys.raspberry-pi Subject: Re: controlling a mains-powered oven Date: Sun, 20 Dec 2015 23:21:57 +0100 Lines: 28 Message-ID: References: <0CLay.46526$051.33662@fx28.iad> <9kg*YMWMv@news.chiark.greenend.org.uk> <_I4cy.38$xz4.32@fx12.iad> <5534ef7698Spambin@argonet.co.uk> <5535055297Spambin@argonet.co.uk> <20151220175452.5ac29e53@debian> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Trace: individual.net UhKmZxxt9SiMNS1X59WIzAVWUoo+ZejPJyR+3L0+EMq8uVFTWa Cancel-Lock: sha1:N6RgNHXF2FFf1bOpFmbfAsXvetg= User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 In-Reply-To: <20151220175452.5ac29e53@debian> Xref: csiph.com comp.sys.raspberry-pi:10166 Am 20.12.2015 um 18:54 Folderol wrote: > On Sun, 20 Dec 2015 16:26:54 +0000 (GMT) > Stuart wrote: > >> In article , >> Kallu Wiegand wrote: >>> My suggestion would be a Solid-State-Relais. >> >> Yes, of course, but you will still generate less of an arc than if the >> contacts open at Max volts. Zero crossing is easy enough to detect and >> anticipate so you cut the relay holding current a few milliseconds before >> zero. > > A relay capable of of safely breaking that kind of current takes upwards of > 15mS to fire, so you would be (variably) about 3/4 the way though a complete > mains cycle. A (theoretical) solution would be a propper treshold. If that dammned^hbad mechanical part wouldn't alter its behavier in such a short time! Some thousend switchings and the timing is far from good and ever changing. -- Have a nice day! Kallu