547: Difference between revisions

The 547's power supply provides regulated outputs of −150 V, +100 V, +225 V, +350 V, as well as a +325 V unregulated output for CRT HV section.

Multiple secondary windings feeds diodes for rectification for different voltages. Both center-tap and bridge configuration is used. Its a all Tube design for the regulation. There are multiple 6.3V secondary outputs for heaters, many elevated to different voltage levels based on the section/tube its used for to keep the Heater-Cathode voltage level within limits.

As is common in many Tektronix scopes, all regulated voltages are referred to the negative regulated rail (−150 V in this case) by fixed low-tolerance dividers. Only the −150 V voltage is trimmed, its reference is a [[OG3]] VR tube. A [[12AX7]] is used as the comparator, two [[6CW5]] in parallel are used as series pass tubes. A [[6AU6]] is used as an error amplifier. Most other stages replicate the same design, except slight changes in tubes used − the +225 V and +100 V regulators employ a [[6080]] as the pass element, +350 uses a [[6CW5]].  

The plate voltage delay circuit is as like in may other Teks, uses  a 6N030 delay tube (P/N 148-0021-00) to control a relay that switches plate supply voltages on only after the tubes are warmed up. Heater voltage is directly applied to tubes on Power on.