power gating boost conversion and mppt solar charging

in the top left there's a model of a solar panel which I determined the maximum power point for and created an input regulation loop to lock it at about 335 mV. This can be bypassed to accelerate charging of the storage which is a 100 mF cap. The storage has its voltage output gated by a Schmitt trigger that enables and disables the load side. The load side, when enabled, goes to a boost converter powered with the 555 timer and some comparison circuitry. This regulated output is then further smoothed by a post-regulator. Run it at 1 ms (sometimes it works with higher speeds but it's iffy) with the switch, then flip it off, sit back and watch. the power gating should kick in at about 540 mV. adjust the load resistor if you'd like and observe the effects on the orange trace (storage) in conjunction with the blue and green traces (regulated DC) I think the duty cycle is 75% after putting it into a calculator, so the maximum boost ratio should be 3x which caps the resistor ratio for the comparison op amp to 2x. Bear in mind that none of these part values are super realistic, but I think it's fun to watch. EDIT: actually I think that there is somem wackiness where the capacitor gets drained without meaningfully discharging into the load. I checked all the curreent paths it was attached to but I couldn't find anything. any thoughts?

published 6 years ago