1,537
edits
555: Difference between revisions
m
Expanded Power supply/Filament Regulation Section
m (555 Power Supply Pics) |
m (Expanded Power supply/Filament Regulation Section) |
||
| Line 52: | Line 52: | ||
The upper-beam sweep and lower-beam sweeps are, in fact, totally independent. | The upper-beam sweep and lower-beam sweeps are, in fact, totally independent. | ||
== Filament Supply Regulator == | == Power Supply and Filament Supply Regulator == | ||
The external power supply unit generates all the B+ Voltages (-150,+100,+225,+330,+350 and +500V) required by the indicator unit. | |||
This is fed to the indicator unit through the interconnect cable. | |||
The heater/filament supply for all the tubes inside the indicator unit are generated by a transformer inside the indicator unit. | |||
Output of this heater/filament transformer is regulated by the external power supply unit by controlling the primary voltage to it. | |||
There are two transformers inside power supply unit. One to generate heater voltage for all the tubes which dont get a regulated heater voltage from Indicator unit. | |||
Second transformer is used to generate all the B+ plate voltages. There is also a saturable reactor inside the power supply, which is part of AC regulator for heater transformer inside indicator unit. | |||
Regulation of the filament supply happens as follows: | Regulation of the filament supply happens as follows: | ||
There is a feedback loop that is formed between the indicator unit and the power supply unit. | The power supply sends and control AC to the primary of the filament transformer in the indicator unit through the interconnection cable . | ||
There is a feedback loop that is formed between the indicator unit and the power supply unit. This is achieved by sending one 6.3V winding output of the heater/filament transformer in the indicator unit through the interconnection cable (part number [[012-032]]) back to the power supply unit. | |||
This performs two functions. | This performs two functions. | ||
First, | First, it is used to heat the cathodes of specific tubes in the power supply unit - V624,V634,V664,V684,V694. | ||
Second, this filament voltage is the feedback signal to a regulator in the power supply | |||
to the filament transformer. One of the consequences of this scheme is that it | Second, this filament voltage is the feedback signal to a filament voltage regulator in the power supply. | ||
the indicator unit | A regulator Tube - 2AS-15, a Temperature Limited Diode - is used to sense this filament voltage and uses it to control DC current through a saturable reactor. | ||
The voltage to the primary of the heater/filament transformer in the indicator unit is fed through this saturable reactor and send to the indicator unit via interconnection cable (part number [[012-032]]). This forms a closed loop to regulate heater voltage in the indicator unit. | |||
One of the consequences of this scheme is that it the power supply unit will not energize the plate voltages (except +100V) without the indicator unit connected. | |||
This is because of the following reasons: | |||
1. Heater to V624,V634,V664,V684,V694 are taken from the 6.3V feedback line coming from filament transformer in the indicator unit. Even though the main series pass (6080s and 12B4s) are heated from a local heater transformer, the 12AX7 comparators and 6AU6 error amplifiers are heated from the indicator unit. | |||
2. The Primary of the plate voltage transformer inside the power supply unit is looped via the thermal cutout in the indicator unit. So the plate voltage transformer in the power supply will not get power unless the indicator unit is attached. | |||
== Vertical Amplifier == | == Vertical Amplifier == | ||