I often see whistle counts mentioned in recipes from the country but all of the more local recipes I have seen relied more upon strict timings.
Does the pressure-temperature relation of the combined gas law hold in the steam regime, considering the weight clamps the cooker to a maximum pressure? It seems like the whistle frequency would be a function of heat input to the system (or rather heat lost) while temperature would mostly be determined by the letoff pressure value. You'd think a longer time or higher temperature would shorten cooking time, not the amount of heat escaping the system. Below the letoff pressure, temperature is a great proxy for pressure (via the combined gas law), and indeed this is how many of the electric pressure cookers "sense" pressure; they have thermistors thermally coupled to the cook pot. Could it be that pressure recovers to the letoff value more quickly at higher temp? That would make whistle counting for temperature roughly similar to the light measurement method of the modulo camera that was discussed a couple days ago[2]. It seems like the diameter of the pot might impact pressure recovery time though.
All that said, it is GREAT to see more cooking tech, OP. Anything that helps people to cook more (or better) can only be a good thing.
Perhaps worth knowing is that there are three types[1] of pressure cookers, and it seems like OP's product could only potentially work for one (?) of them: old-school weight-clamped. Fagor-type pressure cookers release steam constantly, old-school weight-on-top pressure cookers release steam intermittently, and Kuhn Rikon pressure cookers release no steam at all (best for flavor since no volatiles are lost to the kitchen with escaping steam).
If the weighted valve and letoff system is succeeding in staying close to a constant pressure/temperature surely a simple timer would be a better solution.
Mine just releases steam constantly through a valve once it gets to a certain temperature/pressure... but I might just be using it wrong :P
I have a pressure cooker that I've never used. Am I understanding (from the rest of this thread) that I could be attempting to make some sweet Indian dishes with it?
Schematic - https://github.com/s-gv/cookoo/blob/master/schematic/whistle...
