Power resistors are often spaced off the board with two short pieces of spaghetti tubing. If you use metal-housed resistors you can bolt them to a heatsink. Regards, Mark On Tue, Jan 16, 2018 at 12:48 PM, Richard Prosser wro= te: > The old-school way was as shown below - bend the leads around in a loop a= nd > space the resistor off the pcb to permit airflow. But not very vibration > friendly! Adding a topside solder fillet may make the joint more rugged > > Or use a larger resistor that can be properly clamped & heatsunk. > > RP > > On 17 January 2018 at 08:15, 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 AC0= 5. >> 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 >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> >> > > -- > 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 Regards, Mark markrages@gmail --=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 .