A while back I refitted my larger Traeger pellet grill with a new home-built controller.
Unlike my earlier attempt, which was only semi-successful, this is not trying to control the pellet feed (and thus the heat/smoke mix) by temperature control. At its heart is a simple 5 quid timer device, which allows you to set durations (in seconds) of off-states and on-states operating a 12V relay. This in turn signals a main-voltage relay already fitted in the grill, controlling the pellet feed.
I’ve already used this for medium to high temperature cooks, with no problems. But today I am using it for the first time for a long smoke of two pork shoulders. Having just sat and watched it for the last hour, with my morning cuppa, I seem to have locked it in to a steady 180-190° F on a 4:1 ratio (pellet feed 60 seconds off/15 seconds on). I’m quite pleased with this – 180° is the lowest temperature I would normally cook, good for a long slow smoke of 8-12 hours.
The very first controller this grill had, and was supplied with, was timer based, just like this. It worked fine, and although I found it occasionally limiting. But that was simply because it only had 3 settings – Low (smoke), Medium and High. My new timer has endless combinations, and is easily set. It gives me the three settings of the original – 4:1 (slow), 2:1 (medium) , always on (high); and everything in between.