37,092
edits
No edit summary |
No edit summary |
||
Line 85: | Line 85: | ||
The −12.4 V regulator is transistor-based. | The −12.4 V regulator is transistor-based. | ||
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 + | 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 +170 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. | ||
==Links== | ==Links== |