I decided to redesign the input stage. Ive placed the batteries in parallel, and the boost after the batteries instead of before them. The new battery voltage is 1.2v, which is fine for the boost and works well for direct charging off of the full bridge rectifier. I bought two 700mAh NiMH cells. If these are trickle charged at below 1/10 their max rate, (so 70mA), they can be continuously charged without hurting them or severely reducing their lifespans. With my input stage, 3mA is about max at this voltage (see the results from my last post), so i think this will work fine. I hooked up the boost after the batteries as well, and added a switch to turn it on and off.
Here the coils are seen charging the batteries (green waveform is battery current, positive is into the battery), then the boost comes on, (yellow waveform) and then switches back off. Blue is the battery voltage. Ill add a larger input filter to the boost later. Ive now got a decent 5v supply, that runs off of rechargeable batteries. These batteries are charged with a coil through a full bridge and filter. Now i just have to design the timing and logic circuits for the LEDs. Ill probably make a few modifications to the coil/rectifier circuit (Stage 1) and the boost (Stage 2) as well, just to increase efficiency, but what I have now is enough to build the rest of the circuit off of.
No comments:
Post a Comment