Power panel fire

[Former Member]

[This posting has been removed]

[Martin McIntosh]

Rather than reply to the PM`s I shall try to publish it on here for all to see. Only three simple components plus a switch and an ammeter if you wish. I use a separate 1S Lipo rather than the 4S starter supply.

[Nigel R]

No simple mods that I'm aware of.

Google for "AAM glow driver" to find the ultimate solution. A driver that uses the plugs resistance to sense the plugs temperature and drives a pwm chopper accordingly . Add per the rcats unit percy mentioned.

Somewhere I have a diagram for the panel I made which had a simpler circuit that compensated for any voltage input to keep the glow constant when the starter is used. Will post when I can.

[trebor]

Looks a bit complicated Nigel **LINK**

[Geoff S]

Posted by Don Fry on 24/06/2018 19:11:20:

To my mind you will need, a starter with a 4s lipo for power, a 2000 mah will do for anything to 30 cc. And a glo starter. I am a traditionalist, a 2 v lead acid, an ammeter, and resistance( variable). I accept , while being right, I am in a minority.

I charge everything, when I burn a gallon of fuel.

I'm primarily an electric flyer these days but I have a couple of petrol engined models. One has a magneto Zenoah 26 the other a Mackay 30cc with electronic ignition. I've flown both this year and found to my delight both could be easily started using a puffed 3S 2200 LiPo as the energy source for my geared electric starter. The LiPo I used is one I wouldn't dream of using in any of my 3S powered aircraft as an energy source.

So almost any old LiPo will do the job. There's a huge advantage that there's no trailing wire liable to get caught in the prop.

Geoff

[Martin McIntosh]

Here are the details as promised.

The LM388K adjustable regulator can be rather expensive for a genuine Texas Instruments one but ebay will yield these for 2 or 3 £. The capacitor values are not critical and these could possibly even be dispensed with for this application.

The minimum output voltage is 1.25V which is just what we want. A very low value resistor could be added at point R`x` if you wish this to be a bit higher. I often use a switch to toggle between a high and low value but 1.25 is fine since the regulator will maintain this under all conditions. Note that although you can use any i/p voltage up to 37V, anything much above a 1S Lipo will generate a large amount of heat which needs to be dissipated.

I have mounted mine on 2mm alloy and an insulator kit has been used so that the plate is not live. These bits can be bought from CPC. The meter is from an old car battery charger.

Do not omit the switch or the battery will slowly discharge.

The switch and connectors on the right are for the separate starter and fuel pump.

[Former Member]

[This posting has been removed]

[Martin McIntosh]

My starter and pump run from a completely separate 4S2P Lipo with the connectors mounted on the same panel as the glow unit for convenience. Don`t try to run the glow from the starter supply or there could be smoke!

I also have one mounted in a separate box with a cheapo plastic regulator but this needs a thick alloy heat sink. Powered by 3S2P Eneloops.

[Nigel R]

ok, as promised, a link to the plug driver I made

http://www.webx.dk/rc/glow/glow.htm

version 3 has input voltage compensation

I did mine on veroboard, the 20 or so components were quite easy to arrange.

Although I found the values for the resistors which dealt with that portion of the circuit were wrong, I did figure out some values which worked although I would have to dig through my notes at home to find them.

With that fixed it works very well. Its intended for a single 12V battery type setup.

There is also a nice page on the same website detailing a complete panel project with pump switches and a field charge output for old style 4 and 8 cell nicad packs .

http://www.webx.dk/rc/glow/powerpanel.htm

[Former Member]

[This posting has been removed]

[Martin McIntosh]

If you go that way then there is no need for a regulator. The whole idea is that you can use up old puffy Lipos which will then last for years more and require only an infrequent recharge. The regulator chip needs a minimum input voltage or it cannot work.

I have seen many complex circuits for these over the years including resistors and none of them did the job.

[Nigel R]

Not sure what you mean by 'none of them do the job'?

All the various solutions around will 'do the job' of lighting the plug. But if a sub-C type stick is the basic nutcracker, there are many ways to turn the thing into a sledgehammer. The end result is still a cracked nut.

[Geoff S]

I've used a few of those sub C type so called glow sticks and they certainly work but I was never very happy with them teetering clipped to the plug but in danger of falling into the prop. I just fitted a 2v Cyclon into a plastic Maplin's project box with an ammeter etc and used a suitable clip on the glow plug.

However I do like Martin's simple and elegant solution and would certainly make one if I were flying glow powered models regularly.

Geoff

Edited By Geoff Sleath on 29/06/2018 13:08:27

[Nigel R]

My effort, mounted on a 6"x4" bit of aluminium plate.

The glow driver I linked fits on that small bit of veroboard at top right:

Mental note, I really should get around to fitting a proper knob to that glow drive adjustment pot. The ammeter needed a bypass resistor to get it to read around 2.5A when "the average plug" glows nicely.

Sockets on the left are for starter (x2), and external pump (x3, one is for 6V output via a big resistor). Two switches in middle do pump direction & on/off. At some stage I must tidy the pump switches up into a single fill/off/drain switch, wire the pump internally to the box and remove or blank off the sockets.