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This PSU comes from a Vacuum Tube amplifier design I have worked with a few times, and I decided it would make a great demonstration of an increased voltage DC PSU!
Uses a transformer to convert 120 V-RMS to ~160 V-RMS (153.6 V_RMS here) which is then passed through the full-bridge rectifier diodes:
V_DC = 1.414(V_RMS) - 2(V_k)
With V_k typically being 0.7 V for Silicon diodes, 1.2 V for GeAs, and 0.3 V for Germanium diodes.
The 68 uF capacitor smooths the waveform to create a much more steady output.
For this example, a Zener diode with a V_z equal to 50 V was used, and the regulating effect of the output. The ripple voltage can be seen on the output waveforms from the rectifier and across the Zener diode, and the Zener voltage has a significantly improved ripple compared to before the capacitor.
The largest downside to this design would be that the voltage across the capacitor (after the rectifier) shoots up at power on, way above the operating point of this linear power supply. It is crucial when building a linear power supply to account for this, and choose a capacitor that is rated at least for double the expected operating voltage to avoid critical failures of components.
This is an outdated PSU design and should not be used unless you are well aware of the risks and have explored modern alternative options, such as switching mode PSU's.
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