Old field generator?

[TheReturnOfHightower]

Was at a county show today and they had this old beauty on display. Old field generator?

Anyway, thought some of you may appreciate me sharing it.

 

[DPG]

I'm guessing an oil heater, as from experience with old gen sets (never anything like this). Heavy viscous oil due to cold weather would stall the engine on starting.

But the power won't be there if the engine hasn't yet started.

 

[davesparks]

I'm guessing an oil heater, as from experience with old gen sets (never anything like this). Heavy viscous oil due to cold weather would stall the engine on starting.

It's connected to the output, so I don't think it would have any power until after the engine is running,

 

[DPG]

Perhaps it's for heating water to make a brew

 

[Bobster]

But the power won't be there if the engine hasn't yet started.

There could be an aux supply connected though, to pre-start.

Hence not being used in operation.

Also used similar on large gennys and slip ring motors. Some would run a DC voltage through the winding's of the motor to heat everything up. Including the oil surrounding and labyrinth seals.

 

[DPG]

There could be an aux supply connected though, to pre-start.

Hence not being used in operation.

Also used similar on large gennys and slip ring motors. Some would run a DC voltage through the winding's of the motor to heat everything up. Including the oil surrounding and labyrinth seals.

You'd have to be careful not to close the main switch when the aux supply was active.

 

[davesparks]

There could be an aux supply connected though, to pre-start.

Hence not being used in operation.

Also used similar on large gennys and slip ring motors. Some would run a DC voltage through the winding's of the motor to heat everything up. Including the oil surrounding and labyrinth seals.

Where would the aux supply come from? If an aux supply was available for starting wouldn't they have a starter motor rather than hand crank?

Also it isn't used for the Gardner engine, only the original lister. If it was part of the dynamo, which remained unchanged, wouldn't it still be used with the later engine?

Also it would presumably not be connected via the main output switch if connected to an aux supply, the wiring diagram on the brass plaque shows the knife switch output going direct to the output terminals via the fuses

 

[Bobster]

You'd have to be careful not to close the main switch when the aux supply was active.

I may be completely off base, but you're right.

Just like turning the ignition key again on an already running car engine. (Think new models stop you from doing this).

 

[DPG]

Good point, why is it only needed for one type of engine?

 

[Bobster]

Where would the aux supply come from? If an aux supply was available for starting wouldn't they have a starter motor rather than hand crank?

Also it isn't used for the Gardner engine, only the original lister. If it was part of the dynamo, which remained unchanged, wouldn't it still be used with the later engine?

Car battery?

Possibly not enough umph to turn the unit over via a starter motor.

It was only a guess.

 

[marconi]

Is there some sort of automatic voltage regulator (we can see a big black knob on the panel) for setting output voltage which use the output voltage related Ohmic heating of an element as part of a voltage reference device? Did not old car's with dc dynamo have a Lucas black box called a regulator with a heating element inside? I have not a clue how they worked - I vaguely remember taking one apart.

 

[davesparks]

Car battery?

Possibly not enough umph to turn the unit over via a starter motor.

It was only a guess.

We're all guessing here I think, it's certainly turned into an interesting thread.
[automerge]1567514304[/automerge]

Is there some sort of automatic voltage regulator (we can see a big black knob on the panel) for setting output voltage which use the output voltage related Ohmic heating of an element as part of a voltage reference device? Did not old car's with dc dynamo's have a Lucas black box called a regulator with a heating element inside? I have not a clue how they worked.

View attachment 51863

Wouldn't that need to be connected whilst the main output was live if its for voltage regulation?

 

[Lucien Nunes]

Perhaps it's for heating water

Correct.

to make a brew

Not correct!

It's not so much that one type of engine needs it and the other doesn't (although there is a bit of truth in that) as that the Lister was on there when it was a searchlight generator and the Gardner was put on when it was repurposed to power a fairground ride. At fairgrounds, the ride operators have the luxury of choosing when to open for business.

 

[DPG]

To clear condensation or something?

Or some sort of fog clearance?

 

[Lucien Nunes]

There are only two output terminals, not counting the worklight socket and the optional paralleling terminal. The 'fog clearance device' would therefore have to be mounted on the genny trailer for it to be separately switched. I am not seeing such a device...

 

[DPG]

They use water in carbide lamps I believe, but not in wwii arc lamps. Mmm, puzzling.