Other Parts Discussed in Thread: TL431
Hi,
I built up the circuit from SLUA625, Fig. 15, but it does not work correctly. I noticed that the auxiliary coil for T1 was not labeled correctly (should be ZCDA, not ZCDB), so I corrected that before I built the circuit.
The chip seems to be working, as VREF is putting out 6V when I inject 18V from a separate source into the VCC pin.
VSENSE is reading: 2.84V
COMP is reading: 0.675V
HVSENSE is reading: 2.84V
VINAC is reading: 4.95V. For some reason, the rectified 120VAC is coming out as 310VDC. Would this cause issues? I can change the VINAC resistor network as a bandaid.
I expect to see ~60V on my output, since I changed the FB resistor network to regulate the TL431 around 2.5V @ 60V DCBUS voltage.
Let me know what I can do.
Thanks!