Starter-Generators. 2 thingies in one.

[cardiffrob]

Starter-Generators.

Has anyone had any dealings with these things? The technology has been around since the 1920s to use a starter that, after start, reverts to becoming a genny to recharge the batteries. I'm working with such a system right now.

I can't get my head around how they switch between roles. Any thoughts on how they switch over and what logic is needed to do so?

Ta.

Confused, of Burgess Hill.

 

[Robotstar5]

@GRW is probably the man to answer this.

I've only been involved with them in the stationary engine world, I have a lighting set which uses the generator to start by pulling a switch.

You could also google "Lister Startomatic" but it looks a lot more complicated.

 

[daleyd]

A motor and a generator are, at a basic level, the same thing. When I worked in the printing industry we used servo motors and an inverter drive to spin up a 3 tonne roll of paper and then once it was spliced and pulled under tension the same motor would switch to work as a brake/generator. The only mechanical brakes used were when it was at a standstill.

Do you have a particular type you are looking at, as there are likely many different types. Narrowing it down a bit might help in getting the correct info.

 

[dutch2u2]

I have the one of the same units it is called a Tiny Tim came out of WW2 American tank and has 4 carbon brushes
2 used to make it a motor and the other 2 used as the genarator I belive.

 

[George A2Y]

Can you give some more info on the equipment you have?
The Lister Start 'O' Matics have a combined generator/starter, the starter side is usually 24v D/C.
The system was designed as a source of 'on demand ' power, primarily lighting, for a house or building. It was a stand alone system prior to mains electricity being available not intended to be linked with a grid supply.
When the plant was not running & no lights required, all switches off, the batteries could monitor the 240v side and when it detected continuity (light switched on) it would start the generator.
The load on the 240v was then monitored and when it ceased, everything switched off, the plant shut down and then reverted to monitoring with the batteries again.
All battery charging was done during the lighting demand period.

 

[Melvyn Best]

Dynamotor , as used on the Bullnose Morris. I had to remove /refit one last year for repair

 

[sako243]

I can't get my head around how they switch between roles. Any thoughts on how they switch over and what logic is needed to do so?

As @daleyd says in short you don't need to do anything aside from ensure the electronics driving it can handle it.

If you look up and get an understanding of 4Q (four quadrant) motor control then they're doing a weird 2Q variant (driving and braking in one direction, 2Q normally refers to diving forwards and backwards, I.e. Directional control but not braking).

If we think of a starter motor scenario (but exclude the clutch mechanism that engages / disengages the gear). When the engine is not running and power is applied to the starter motor then huge currents are drawn because the motor, at stationary, is basically a dead short. Once it starts to rotate the engine then the current draw becomes less as the torque required is reduced.

Once the ICE engine fires up it basically overpowers the starter motor and the current required by the electric starter drops off to zero. However if the starter stays engaged in the flywheel then the ICE engine will keep powering it. This generates a voltage at the output terminals and if you provide somewhere for this to go (e.g. A battery) then current flows and it becomes a generator.

 

[OJCar]

A Volvo Penta boat engine I had had a starter/generator.
It was just a couple of relays controlled when it was a start and when a dynamo.

I'll look and see if I still have the Workshop Manual as it had a very good description of how it worked.

 

[eddie49]

My first motor vehicle was a Messerschmitt KR200 bubble car. The 191cc engine was fitted with a SIBA "Dynastart" electric starter, which worked as a 12v generator when the engine was running. It could also start the 2-stroke engine backwards ( two contact breakers were fitted ), giving 4 reverse gears....

 

[Ubique]

Lots of hybrid cars have them, typically the 'starter' operates at 48VDC to reduce the size of winding required, some, but not all also output at 48VDC with the 12V side supplied and the separate battery charged via a DC-DC converter.

 

[CompoSimmonite]

I found, by accident, if you "fiddle" about with the voltage regulator on old cars with a dynamo then it spins like a motor Petrol golf cars often have a dyna-start system

 

[500e]

Old Dodge, Rio, vehicles used them , I have one on the bench at present
Also RR Alison, turbine engines use them.

 

[cardiffrob]

It's on a Learjet 45 fitted with a TFE-731 jet engine and , presumably, a Lear starter-gen. They don't like Pilots to know too much in case they start to 'tinker'. Engineering diagrams are not readily available unless you dip into your pocket for a fat wedge of cash. It should run off of 2 big 24-28 v batteries and then cut out at 50% rpm before instatly turning into a 300+ amp generator.
It's shaft driven off of the engine core.

 

[OJCar]

I think the Volvo Penta Dynostart is not quite in the same league as a a Learjet ...

I may have a Rover 1S60 manual somewhere...

I've realised that I sold the Volvo manual some years ago , sorry.

 

[Tinbasherdan]

It's on a Learjet 45 fitted with a TFE-731 jet engine and , presumably, a Lear starter-gen. They don't like Pilots to know too much in case they start to 'tinker'. Engineering diagrams are not readily available unless you dip into your pocket for a fat wedge of cash. It should run off of 2 big 24-28 v batteries and then cut out at 50% rpm before instatly turning into a 300+ amp generator.
It's shaft driven off of the engine core. View attachment 489138

It’s not strictly Lear, but have a look at this link, might be able to pull enough off to teach a pilot how witchcraft works!

https://www.faa.gov/sites/faa.gov/files/07_amtp_ch5.pdf

 

[GRW]

I've no direct experience of the combined alternator/starter... but as others say, the rotor and stator are the same effectively.
In an alternator you put mechanical turning motion IN to get electrical power OUT. In a starter (or electric motor) this is just reversed.
In the late 70's a Yamaha DT100 (I'm pretty sure it was) used a combination starter/charger unit (though anecdotal tars of the time said it wasn't that great, ad the bike had a backup kick-start that was generally employed from cold.

Lister Start-o-Matic really only relates to the load-sensing Start Panel, not the actual start method btw. It's true that a lot of pre-80's Listers didn't use a starter motor - but they didn't use the main alternator output winding to crank over the engine.... there was a dedicated 24v starter winding in the alternator casing that turned the rotor and cranked the engine (in conjunction with a convoluted system of twin solenoids and linkages - one engaged the fuel, while the other actuated the decompressor levers to give the starter winding an easier time).

 

[GRW]

Can you give some more info on the equipment you have?
The Lister Start 'O' Matics have a combined generator/starter, the starter side is usually 24v D/C.
The system was designed as a source of 'on demand ' power, primarily lighting, for a house or building. It was a stand alone system prior to mains electricity being available not intended to be linked with a grid supply.
When the plant was not running & no lights required, all switches off, the batteries could monitor the 240v side and when it detected continuity (light switched on) it would start the generator.
The load on the 240v was then monitored and when it ceased, everything switched off, the plant shut down and then reverted to monitoring with the batteries again.
All battery charging was done during the lighting demand period.

Most start-o-matic systems weren't used with a DC battery system (though some people did run separate 12vdc lighting circuits as well).
When Inverter/Chargers became more reliable and affordable - we'd then install battery-inverter systems in system with the site (very often a Lister twin) generator.... but we'd have to convert the genny panel from S-O-M to "Remote Start" (1. So the inverters brain could send start/stop signals as needed to the genny, but also 2. as a S-O-M panel would always "see" the inverter as a "Load" and want to run permanently).

 

[Gritineye]

I have a small BSA (Chorehorse) army petrol charging set that self starts if connected to a battery, ex reserve stock, no idea why I wanted it as it only ever gets used as it a trip hazard!

 

[chrismac]

Most start-o-matic systems weren't used with a DC battery system (though some people did run separate 12vdc lighting circuits as well).
When Inverter/Chargers became more reliable and affordable - we'd then install battery-inverter systems in system with the site (very often a Lister twin) generator.... but we'd have to convert the genny panel from S-O-M to "Remote Start" (1. So the inverters brain could send start/stop signals as needed to the genny, but also 2. as a S-O-M panel would always "see" the inverter as a "Load" and want to run permanently).

Are you referring to newer start-o-matic systems here, asking on an interested level not questioning your knowledge!, as the older (first 5hp CS engine SOM's with the direct drive alternator were called lighting plants and supplied was it 110v to a battery bank for lighting then following on from them we have the 6 hp CS engine which had the 24v battery for starting with the load sensing circuit, these are obviously early models in the SOM era and the later air cooled versions were taken into play subsequently.

Thanks, I have dabbled in the stationary engine world thats where my interest comes from.

Chris

 

[Justme]

Lots of hybrid cars have them, typically the 'starter' operates at 48VDC to reduce the size of winding required, some, but not all also output at 48VDC with the 12V side supplied and the separate battery charged via a DC-DC converter.

On mine its about 208v.