Path: utzoo!attcan!uunet!fernwood!oracle!news
From: oparadis@oracle.uucp (On G. Paradise)
Newsgroups: sci.electronics
Subject: Re: Light Dimmer
Message-ID: <1990Dec12.001342.6799@oracle.com>
Date: 12 Dec 90 00:13:42 GMT
References: <2570007@hppad.HP.COM> <3450@exodus.Eng.Sun.COM> <1990Nov27.201653.4865@hayes.ims.alaska.edu> <713@ginger.dfrf.nasa.gov> <1990Nov29.135257.24309@specialix.co.uk>
Reply-To: oparadis@oracle.UUCP (On G. Paradise)
Organization: Oracle Corporation (Federal Division), Bethesda, MD
Lines: 21

Most of the problems with el-cheapo dimmers in those $40 halogen
lamps can be solved by:

1. Adding a resistor in series with the triac gate, to get rid of
   potentiometer backlash.

2. Getting the diac trigger voltage through a double RC network,
   to obtain zero through 360 degrees of conduction.

3. Adding a pi (CLC) network to reduce RFI.

Way back in the '70s, RCA had schematics and values for these in
one of their triac data books. They also mentioned:

4. Connecting a snubber network across the triac (MT1 - MT2) for
   dV/dt control of inductive loads.

My old RCA databooks are long gone.  Can anybody look thses up and post
the values?

On