VOLTMETER TYPE S78.3.587
LEADING PARTICULARS
| Stores Ref. No.: | 5Q/107 (and later 5Q/4347724) |
| Manufacturer: | Sangamo Weston |
| Attachment: | 28D/1213896 | AS.3295/2B | Bolt, 4 BA phillips recess, 90° csk |
| Connection: | Screw terminals |
| System: | Electrical Distribution |
DESCRIPTION
DC voltmeter to indicate the voltage of main DC distribution busbar, circuit ID: 'PL'.
It was fitted to all Mk's of Lightning, however the T5 and T55 were fitted with two, one on panel A1, the other on panel A2-ext.
The voltmeter(s) will read around 24V or less when just the battery is connected to the bus bar, an when either external power is conncted or the main generator is online, it will read about 28V.
SIMULATION
Busbar PL is energised if:
- Battery Master switch is on, connecting the battery busbar PE to busbar PL via the battery isolating relay.
- External power is connected supplying to busbar PL via the ground supply relay.
- Main DC generator is in operation and connected to busabr PL via the main contactor.
- Standby DC generator is in operation and connected to busabr PL via the standby generator contactor.
It would be nice to show the battery voltage drop and recover when DC loads are switched on/off but so far I have only modelled the voltages of the DC electrical system, not yet the currents.
This initial test video shows the genuine performance of the indicator as 28V is applied and removed as a step change, the pointer overshoots and settles down, exactly as it does in the real Lightning aircraft.
CIRCUIT DIAGRAM
The T Mk.5 aircraft wiring diagram taken from AP101B-1005-10 Sheet 41, Fig 1A, A.L.3, Nov. 1981.
WANTED
I have one of these. As you can see above, the T5 and T55 used two, so am looking for another, please see support if you can help.
REFERENCES
T Mk.5 electrical "Vol. 1":
A.P.101B-1005-1B, Sect 6, Chap 9, A.L.49, July 1971 - DC power supplies - Paragraph 29