Lots of solders available with much higher melting points. Any reason you can't use those? On Jan 16, 2018 17:31, "mbaum7901" wrote: > I have seen the electrical connections to heating elements be spot welds. > > -----Original Message----- > From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf > Of > Allen Mulvey > Sent: Tuesday, January 16, 2018 17:08 > To: 'Microcontroller discussion list - Public.' > Subject: RE: [EE] Resistor temperature rise > > If I recall correctly there was some Korean War era stuff that had spot > welds. > > Allen > > -----Original Message----- > From: piclist-bounces@mit.edu > [mailto:piclist-bounces@mit.edu] On Behalf Of mbaum7901 > Sent: Tuesday, January 16, 2018 5:18 PM > To: 'Microcontroller discussion list - Public.' > Subject: RE: [EE] Resistor temperature rise > > One approach is a mechanical rather than solder connection to the resisto= r > lead. > 1. Tack or spot weld > 2. Crimp > 3. Screw terminal > > The resistor wattage rating and corresponding temperature rise curves > describe what you can do with the resistor before the resistor fails (bur= st > into flames). The actual resistor wattage selection is then a function o= f > the system design. > > The 5 watt resistor is really good for 5 watts if the system usage has th= e > resistor body and leads in contact with surfaces that can withstand the > resulting temperatures. > > I am currently repairing a Ford F-250 overhead display console which has > 1206 resistors that run so hot that they melt the solder and fall off the > board. > > -----Original Message----- > From: piclist-bounces@mit.edu > [mailto:piclist-bounces@mit.edu] On Behalf Of David C Brown > Sent: Tuesday, January 16, 2018 15:54 > To: Microcontroller discussion list - Public. > > Subject: Re: [EE] Resistor temperature rise > > High melting point solder? > > On Tuesday, 16 January 2018, Bob Blick > wrote: > > > What techniques are most effective in keeping power > resistors from > > desoldering themselves from PC boards? I'm thinking there > are > > basically three methods: > > > > 1. Don't use them at anywhere near their rated power. > That's fine > > except if you need to tolerate the occasional overload > condition. > > > > 2. Pour extra copper on and around the pads. > > > > 3. Use as much length of the wire leads as possible. That > could really > > decrease the rigidity of the mounting. > > > > 4. ?? > > > > Attached is a picture of the temperature chart. I'm using > the 5 watt AC05. > > Note the 260 degree K rise at rated power. > > > > If I fold or clinch the leads it will keep the resistor > from falling > > out, but the solder is going to melt. I imagine that won't > give the > > greatest electrical connection :) > > > > Datasheet here: > > > > http://www.vishay.com/docs/28730/acac-at.pdf > > > > Thanks, > > > > Bob > > > > -- > __________________________________________ > David C Brown > 43 Bings Road > Whaley Bridge > High Peak Phone: 01663 733236 > Derbyshire eMail: dcb.home@gmail.com > SK23 7ND web: www.bings-knowle.co.uk/dcb > > > > > *Sent from my etch-a-sketch* > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change > your membership options at http://mailman.mit.edu/mailman/listinfo/piclis= t > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change > your membership options at http://mailman.mit.edu/mailman/listinfo/piclis= t > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change > your membership options at http://mailman.mit.edu/mailman/listinfo/piclis= t > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .