36,479
edits
m (added delay tube Part No) |
No edit summary |
||
Line 70: | Line 70: | ||
There is a remote control cable/switch, | There is a remote control cable/switch, | ||
part number 012-0102-00 (photo below), that can erase the screen and reset the single sweep. | part number 012-0102-00 (photo below), that can erase the screen and reset the single sweep. | ||
=== | |||
549 | ===Power Supply=== | ||
The 549's power supply provides regulated outputs of −12.4 V, −150 V, +100 V, +225 V, +300 V, +350 V, and +500 V as well as a +475 V unregulated output. | |||
Line input is connected to main transformer primary via two switches, one to select 110/230V Range - (which is inside the chassis) and another switch (on the rear of the chassis) to select Low/Medium/High voltage range in both the above line voltage class. | Line input is connected to main transformer primary via two switches, one to select 110/230V Range - (which is inside the chassis) and another switch (on the rear of the chassis) to select Low/Medium/High voltage range in both the above line voltage class. | ||
Multiple secondary windings feeds diodes for rectification for different voltages. Both center-tap and bridge configuration is used. | Multiple secondary windings feeds diodes for rectification for different voltages. Both center-tap and bridge configuration is used. | ||
Transistors and/or | Transistors and/or tubes are used for regulation. | ||
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 [[5651]] VR tube. A [[12AX7]] is used as the comparator, three [[12B4]] 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 +350 V, +225 V and +100 V regulators employ a [[6080]] as the pass element. | |||
The −12.4 V regulator is transistor-based. | |||
The | The 549 power supply uses a [[delay relay|6N030 delay relay (P/N 148-0021-00)]] to control a relay that switches supply voltages on only after the tubes are warmed up. On power up, only heater voltage is applied to the tubes. After a delay of up to 60 seconds, the thermal delay relay activates the main relay (driven from unregulated +100 V). This also cuts out the delay relay, which can cool down and will be ready to delay again even after a quick interrupt in power input. | ||
This | |||
==Links== | ==Links== |