So, two little switching power supplies, one for the DOB-50 and CTC-5 as they have similar operating voltages, and one higher voltage one for the DOB-80, a simple op-amp comparator to output the pulses to an Arduino to process and display the results.
The power supplies are controlled using two MC3406AD’s, driving an IRF840. I’ll just refer to the component numbers on the top supply, the bottom one is almost identical. The back EMF from the inductor L2 is rectified by a UF4007. There’s a feed back loop, R14,15 & 16 and the pot is used to adjust the HT..
More details on Doz’ blog.
Check out the video after the break.