[TriEmbed] SSR sources: was Re: T-962 reflow oven notes

[Michael Fulbright]

I'm going to hijack this thread slightly as I was about to ask this 
question and it is related to reflow ovens...

I'm starting to build a reflow solution and I've been researching solid 
state relays.  There are some nice "brand name" relays on Digikey 
(Panasonic, Omron, etc), but then there are a bunch of low-end 
alternatives that are 1/3 the cost.  If you read reviews and look at 
other reflow projects on the web they seem to do OK - but since we're 
controlling main voltage I'm more than happy to spend more money for 
some insurance against a disaster.

Could anyone comment on their personal experience with SSR devices?  I'm 
looking at 25A and 40A.

For now I figured I'd mess around with a homegrown PID solution just so 
I could learn more about it.

Thanks,
Michael Fulbright


On 9/24/2014 6:24 PM, Rick wrote:
> Good evening all,
>
> Pete ... I'd suggest a nice 1/4" aluminum plate upon which you place 
> your PCBs. Your thermocouples can either be taped to your board 
> (kapton is great for this), or permanently fastened to the aluminum. 
> You need some nice thermal mass to reduce your setpoint oscillation.
>
> Does your PID controller have a training mode? If so, install the 
> aluminum with the thermocouples, train it, and then run a profile with 
> an external thermocouple not tied to the system watching as well.
>
> You probably want a HEPA filter on the exhaust port ... though I'd 
> provide some cooling in the form of an aluminum vent pipe before the 
> filter ... no need to get the filter hot. You can buy a large HEPA 
> filter and cut it down to make multiple small ones if you wish (the 
> local home improvement stores carry a few HEPA filters ... beats 
> ordering and waiting for the boat from overseas). You probably don't 
> want to spend the money on an automotive "cabin" filter ... very 
> expensive for what it provides.
>
> Cooling the exhaust also helps condense the volatiles and helps reduce 
> the filter loading ('cause you can shake the filter off rather than 
> replace it every x hours).
>
> Hope this helps,
>
> Rick
>
>
>
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