I built a 10W multi-output flyback all of my outputs are reasonable except one my -12V output, it varies widely over line and load from
-12.5V full load to -18.7 no load.
I've been tinkering in spice trying to come up with a low parts solution but I'm not having any luck. I know I can buy an LDO but I don't want to place an order just for that.
Here is the Flyback schematic. U10 being fed off the +5Vdc output is a
3.3 V LDO. The -7Vdc output feeds a MC7905 on another PCB which is bolted to the front of the enclosure. Oddly enough the -7Vdc hardly moves over line load variations go figure. The negative outputs are for 0.150A full load.If anyone has any suggestion fire away please: