I have the following circuit with a 10k 0.5w trim potentiometer.
The voltage after the bridge rectifier is maintained at ~8.6 Vdc. The voltage is fine when I do not fully turn the pot to 270°. At 270° turn suddenly the voltage begins to fluctuate wildly between ~2 - ~5 V as shown by the picture below.
What is causing this effect? Is this an issue with the pot, capacitors, etc?