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[Netleyned]

The pos and neg pins on the receiver are on common rails
i.e all pos on one rail and all neg on the other
so every channel has a voltage on the pos and neg pins allthe time the rx is switched on
Control is achieved by pulses on the third pin connected to a servo amp, esc or switcher unit.

Ned

[Corposant]

Ned

I have been assuming that the third pin gives a pwm signal for the proportional channels and either 4.8V or 0V for the switched channel. Is the control pin not held constantly at the positive rail voltage when switched on?

Mike

[Netleyned]

You need someone better versed in the black art than me.
I just thought if it was that easy why bother with the expense of switcher units.


Ned

[Corposant]

Ned

That was the thought which prompted my initial question! And here was me thinking you were going to give me the definitive answer!

Mike

[BigA]

Servos do not 'give out' voltage


Ned

It not a switchable voltage it is constant

I meant r/x...... And, yes, the output does depend on the voltage input to the r/x.

[BigA]

Ned

I have been assuming that the third pin gives a pwm signal for the proportional channels and either 4.8V or 0V for the switched channel. Is the control pin not held constantly at the positive rail voltage when switched on?

Mike

The control pin doesn't matter - as long as you wire up the LED/bulb to both the positive and negative pins - ie you can dispense with the white (signal) wire if using a standard servo connector including an on/off switch in the +ve line and you can switch the lights on when required (perhaps even via a servo-controlled micro-switch).  Ned makes a good point, though - the r/x voltage output depends on the output of the battery pack used - in my case, I'm using a 6V pack, so can connect two 3V LEDs in series from the r/x channel 

A.

[BigA]

And the voltage supplied to the r/x may depend on the ESC used! Although I guess most ESC's are standardised on output..... Before connecting things up, I checked the output voltage from the r/x with a multimeter. I use Mtroniks ESC's and Cirrus 40MHz FM r/x's.

A.

[Martin (Admin)]

"Some time ago, I thought of cutting a slot in the mast for the end of the aerial but then decided it would be difficult to remove if one needed to take the receiver out of the hull. " - You could alway install a small straw up the mast so the aerial lead would be removeable but as you WILL be using shiny new 2.4Gig radio it won't need one!

"Powering the LEDs from the r/x is fine, providing it can output the necessary voltage and current" - An additional benefit would be that if the lights get very dim, you would know to bring the boat in pretty quick!

[Corposant]

BigA

If I use the positive and negative pins, I'll need another controlling switch, as you say - but I don't have any spare channels (I'm using all five proportional channels for other things). My ESC doesn't have a BEC, so it would be simpler to use another small battery rather than put the extra load on the Rx pack. My hope was to use the Rx as a switched circuit without any extra electronics.

I'll just have to drag the 'scope out of the loft and see what the signal looks like!

Mike

[Netleyned]

The other drawback is , if you get a short on your lighting circuit and the Rx is supplying the power,
it could turn out to be a very expensive fuse

Ned

[Corposant]

Martin

"A shiny new 2.4Gig radio" Now that would be nice!

Using the lights as a battery indicator - good thinking - but not too reliable if the sun is shining!

Thanks again for your thoughts!

Mike

[Corposant]

Ned

And it would happen in the middle of the pond! I could (would) install a 100mA fuse in the circuit though.

Mike

[Corposant]

We have a definitive answer!

I went on a sortie to the loft and raked out the 'scope - it still works!

And the answer is: the switched Rx output is a PWM signal. (Same as a proportional channel at full throw.)

So a P43 would be needed......... unless, of course, LED's don't mind a PWM signal. Flicker might be a bit fast though!

Mike

[ooyah/2]

Mike,
In my Puffer SKYLIGHT I used Grain of wheat 12 volt bulbs from a 6v battery for the mast head light and the Navigation lights.
12v bulbs on 12v give a very bright light where the 12v on 6v give a more realistic oil type light.
I made the mast from brass tube with the top section in wood and threaded the wires up the inside to the lantern which was made from a piece of 1/4" dia tube with brass plates soldered top and bottom.
As the mast was collapsible I made the Tabernacle from brass with a pin thro' as a pivot which allowed the boat to be stowed in the car and the wires came up from below deck thro' a hole in the tabernacle base plate so that they were all hidden.
The derek boom was made from brass tube with wooden end plugs and a swivel pin which located in 2- lugs soldered to the brass part of the mast.

Some of the Puffers had this collapsing mast as they had to get under several bridges on the Clyde to get access to the city center.
I think that some time after 1945 the boats had generators which powered the lights and the new fangeled telephones that were installed, much to the annoyance of the skippers as they no longer could hide.

My lights were operated by a mini servo below deck and I never used all the electronic switches that were available as I am not electronic wise I used tha simplest of switches, hope this is of some help.

Look close and you can see the brass part of the mast and Derek boom.

 Tabernacle with hing pin and mast head light

Derek boom with swivel pin attachment.


Hope that this is of some help.
How is Mrs C keeping ?
George.

[BigA]

We have a definitive answer!

I went on a sortie to the loft and raked out the 'scope - it still works!

And the answer is: the switched Rx output is a PWM signal. (Same as a proportional channel at full throw.)

So a P43 would be needed......... unless, of course, LED's don't mind a PWM signal. Flicker might be a bit fast though!

Mike

Do you mean the output from the signal pin - the pin (normally the middle pin) that would connect to, say, the white wire of a servo? The output from the +ve pin should be at a constant (supply) voltage - it's the signal pin that provides the modulation. Although an in-line fuse is a good idea, the same shorting risk applies to any electrical unit/component connected to the r/x. I personally don't worry about lights shorting with this set-up - the Cirrus r/x is cheap.

[Corposant]

George

I agree grain of wheat bulbs look much better than LEDs (where you have to "rough them up" in an attempt to get the same effect). Run at half voltage, they're never going to burn out but five of them would draw significantly more current than LEDs. However, I now know that it is not feasible to run the lighting directly off the Rx, so, with an alternative power supply, a slightly greater current drain would be no problem. Plus no calculations to get the right resistor!

My first thought for a hollow mast was aluminium tube but, as it was for the aerial, I quickly thought "you twit", the RF signal would struggle a bit here! Hence the change to plastic. I might try this, although Martin's channel up the side has great appeal (now the mast is going to be fairly easy to remove - but I'm still jealous of your Skylight's and Brian's Sealight's folding arrangement!).

It seems, from what you say, that oil lanterns are the order of the day - there can't have been many puffers built after 1945!

Thanks for the pictures - good to be reminded of your superb build! Thanks too for asking about Mrs C. She is doing brilliantly. We had a few days on the Isle of Wight last week and she mananaged to walk from Freshwater Bay over Tennison Down to the Needles and back - round trip of a good seven miles! The trouble is she is now back to nagging me to get my puffer finished!

Mike

[Corposant]

BigA

Yes the output from the signal pin, not the power supply rails. I had thought (i.e. hoped!) that, for the switched channel, the receiver would simply pull the signal pin up from 0V to supply voltage - hence my original question. In fact, it obviously uses the same circuitry as the proportional channels (there is a certain logic here!), simply missing out the pot. driven by the stick. The peak voltage is around 3.5.

I agree the chances of a short are remote with a simple lighting circuit such as this but I'm rather tickled by your idea of using the Rx as a fuse!

Mike

[BigA]

BigA

Yes the output from the signal pin, not the power supply rails. I had thought (i.e. hoped!) that, for the switched channel, the receiver would simply pull the signal pin up from 0V to supply voltage - hence my original question. In fact, it obviously uses the same circuitry as the proportional channels (there is a certain logic here!), simply missing out the pot. driven by the stick. The peak voltage is around 3.5.


Mike

Ah - now I understand where you're coming from. In any case, why not just power the lights from constant supply voltage of the +ve and -ve pins of the r/x with optional manual switch and/or fuse?

[Corposant]

BigA

Now I know what's available from the Rx, I agree it could be used as a power supply - the only drawback being the additional (very small and for limited periods) current drain. So, my options for switching are a) use R/C with additional circuitry (ACTion's P43), b) a light sensitive switch or c) use your suggestion (simplest of all!) switch them on at the pond side.

Many thanks for your responses.

Mike

[ooyah/2]

Mike,
This is a pic of Skylight in her last days, she was left to rot in the dry dock at Port Glasgow, I will post some more pics as this was a trial run.
George.

[ooyah/2]

Mike,
Skylight was built at Fergusons yard along with her sister ship Starlight in 1937.
Starlight was broken up in 1967 and Skylight at a later date was converted to a Motor launch and renamed SITKA.
I had the notion of a Puffer about 1999 and Skylight drawings were obtained from M.A.P. and redrawn to 1/2" Scale.
I then discovered that she was lying in dry dock at Port Glasgow and was rotting away, I was able to get the general picture of some of the fittings
About 6-7 years ago the frontage at Port Glasgow was being re developed and she was broken up and the dock filled in, but I was fortunate that I took some pics before the breaker came in.

Pic No1, lying in flooded dock.


Pic No 2 , looking down at the hold,
 .

Pic No 3 , you can just see the name SITKA which is a Norwegian Fir Tree



Pic No 4, shown at bottom.


Pic No 5, the stern light bolted to the stern rail.



Pic No 6 Toilet on Starboard side.



You are quite correct in saying that there wasn't a lot of steam puffers after 1945 but there were quite a few VIC's built with steam engines, but alas so few left.

Last pics of how she would have looked after Launching





Mast folded for transportation.




Pic No 4, don't know what happened but pic is out of numerical order, Tabernacle with lugs to hold the swivel pin of the derrick



Glad to hear that Mrs C is much better.
George

[Corposant]

George

Thanks for the nostalgic pictures - she looks just about restorable at that stage. Isn't her engine in the Scottish Maritime Museum?

Your model really does look "the business" - I still can't believe you sold her!

Mike

[ooyah/2]

Hi Mike,
You are very well informed, her engines are in the David Elder shed at the museum in Irvine along with a few other big steam engines.
The Museum is well worth a visit if you are ever in the area.
I sold the Puffer as I was made an offer that I couldn't refuse besides I wanted to develop my Flash Steamer and I have just completed a D10 for my tug CERVIA which I still have to run in and I was running out of storage space so some thing had to go.
If I ever wanted another I still could make one but as I am more of an engine and boiler builder, than a boat builder I have no regrets.

I look forward to you completing your Puffer and some pics.

George

[Corposant]

George

I'd love to pay a visit - bit of a trek from Hampshire though! We seem to visit Scotland about every five years, so there's hope. It would be great to go aboard Spartan and I assume that's where the VIC32's boiler ended up (which I had the privilege of stoking, briefly, many years ago).

My ultimate ambition would be to make a steam plant small enough for a 1:32 model - but it will have to stay as a pipe dream! (Pardon the pun!)

Mike