{"id":1439,"date":"2016-12-26T01:39:21","date_gmt":"2016-12-26T01:39:21","guid":{"rendered":"http:\/\/avitech.com.au\/?page_id=1439"},"modified":"2016-12-26T01:39:21","modified_gmt":"2016-12-26T01:39:21","slug":"dec-871b-power-controller","status":"publish","type":"page","link":"https:\/\/avitech.com.au\/?page_id=1439","title":{"rendered":"DEC 871B Power Controller"},"content":{"rendered":"

\"\"<\/a>The 871B Power Controller is a single-phase 240VAC power controller found in some PDP-11 systems. It has 6 switched power sockets.<\/p>\n

It has a small ON-OFF-ON double-throw centre-off toggle switch. With this switch in the OFF position, there will be no mains power at the power socket.<\/p>\n

Power can be switched on manually (to all sockets simultaneously) by moving the small switch to the “LOCAL ON” position. <\/p>\n

The “AUX ON\/OFF” switch on the front panel of a BA11 cabinet can also be connected to the J1 or J2 connectors on the 871B. If this is done, power can be switched ON\/OFF from the front panel of the BA11, if the 871B’s small switch is in the “REMOTE ON” position.<\/p>\n

Inside the 871B is a small DC power supply, which is always on whenever the circuit breaker is in the ON position. This power supply closes the large relay inside the 871B, to switch mains voltage to the 6 power sockets.<\/p>\n

Power Sockets<\/h4>\n

The power sockets on the 871B seem to be DEC’s standard connector for single-phase 240VAC equipment. Note that the two power pins are turned at 90 degrees, relative to the standard U.S. 120VAC power connectors.<\/p>\n

DEC’s LSI-11 Systems Service Manual<\/a> shows (at page 60) that the part numbers are as follows:<\/p>\n