Tim Cheal Posted January 13, 2019 Share Posted January 13, 2019 Hi Guys I am not sure if anyone can help me, but its a really simple question I was after some advice with. I presently use a Power Panel to drive my starter and glow plug, I can see if I have good contact with he plug by the ammeter indication. But, I also have a nice 2v battery which I can use. The only thing is I get no indication of whether the circuit is made. So, I have two thoughts for solutions. One, wire the 2v battery through the power panel ammeter - but I couldn't see an easy way to do this. Or, put something in the circuit with the 2 volt battery. Is it as simple as putting 2v led in the circuit, or even a small digital ammeter? I have to confess that I couldn't readily see a 2v led to be honest. Your thoughts gratefully received. Tim Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 13, 2019 Share Posted January 13, 2019 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Peter Christy Posted January 13, 2019 Share Posted January 13, 2019 5 amp (or so) meter from an scrap car battery charger works fine. Most plugs draw in the region of 2-3 amps. You may be able to find some on ebay. A search for "5 amp analogue meter" turns up quite a few. Personally, I prefer a single C or D cell NiMH. These have plenty of punch for a plug, and will light any 1.5 or 2V plug. With a freshly charged 2V acc its easy to over-drive a plug, shortening its life. They should glow cherry red, not bright orange! -- Pete Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 13, 2019 Share Posted January 13, 2019 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Cheal Posted January 14, 2019 Author Share Posted January 14, 2019 Thanks all. I’ve an old power panel I could break apart and use the ammeter and the adjuster if you think that would work? Has anyone used an LED in series? Tim Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted January 14, 2019 Share Posted January 14, 2019 Posted by Tim Cheal on 14/01/2019 07:04:42: Thanks all. I’ve an old power panel I could break apart and use the ammeter and the adjuster if you think that would work? Has anyone used an LED in series? Tim Put the LED in Parallel Tim, with a protective resistor It will only light up when you are connected, and is not affecting your circuit Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 14, 2019 Share Posted January 14, 2019 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted January 14, 2019 Share Posted January 14, 2019 Tim, we are going to get confused here as two options are going on. There is the 12v power panel And the 2v Cell, which we need to know the capacity. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted January 14, 2019 Share Posted January 14, 2019 "Has anyone used an LED in series?" It's not quite that simple... I would forget the power panel for now. If you want to use the 2V battery, use the old trick of a very long wire, to drop the voltage at the plug a bit. As mentioned, a 5A analogue ammeter, in series, will do what you want, as regards indication of current through the plug. However. I concur with Pete, the simplest (demonstrably) and best (my opinion) answer is a rechargable sub C, either in a glow stick or on the end of a short cable. You can get them with small ammeters built in. https://www.rcworld.co.uk/acatalog/Aluminium-Glowstart-with-meter-2400mAH-1.2V-NiMH-and-UK-Charger-L_FS_GS02.html#SID=111 Quote Link to comment Share on other sites More sharing options...
Tim Flyer Posted January 14, 2019 Share Posted January 14, 2019 How about putting the 2v battery in a separate little box and buying a new ammeter and installing they on the box lid . It makes a very handy accessory. That’s what I did and I’m very happy with it . An ammeter costs about £2.00 so very cheap. I bought mine online it’s goes up to 6a . If you separate the glow battery from the power panel it also means glow leads can be easily kept behind the engine to avoid the propeller. 😊 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted January 14, 2019 Share Posted January 14, 2019 I generally use a glow stick as they are convenient but also keep an old MFA glow box in the flight box . It's been modified with a "D" cell NiMh . The box has an ammeter that shows current is flowing and being only 1.2 v nominal it can't blow a plug ,unlike a turned up panel and lasts for months between charges. The MFA boxes often turn up at swapmeets etc and are a good investment/ project . The power panels seem to be getting worse in relation to quality and longevity ,probably to keep prices low as sales decrease due to the popularity of electric models. Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 14, 2019 Share Posted January 14, 2019 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted January 14, 2019 Share Posted January 14, 2019 Slightly off topic, but I've just taken delivery of one of these with the aim of making a glow box like Tims. Quote Link to comment Share on other sites More sharing options...
Keith Berriman Posted January 14, 2019 Share Posted January 14, 2019 Here is my Glow Driver set up with a single 4000mah Nimh D Cell Edited By RC Plane Flyer on 14/01/2019 18:25:52 Quote Link to comment Share on other sites More sharing options...
Tim Cheal Posted January 14, 2019 Author Share Posted January 14, 2019 HI all, thanks for the replies so far, and suggestions. Supertigrefan raises some good questions, so let me expand. I currently use a power panel with 12v battery for my starter and glow driver, but when the battery gets tired I find the glow doesnt always sustain when the starter is being cranked. In these instances I can flick start the engine and normally its fine, so I am only looking at belt, braces and another belt! The 2v cell I have I cant get at right now, but I think it is 4.5A. So, my extra belt was to carry the 2v battery with me, and suitable connectors for my glow driver and just switch it over if I note the 12v battery dropping off. Then I thought I could tidy this all up and incorporate something similar to the glow boxes above into my flight box (which is on wheels). Thus, the desire for some kind of ammeter/led and the possibility of using the ‘pot’ from the power panel. So, the questions continue. Will any ammeter do (as suggested a couple fo quid up to 6A)? Is there a 2v ‘pot’ available rather than th eone off the power panel? If I use a long wire to drop the voltage, how long is very long? Thanks again for all your help. I know I should just wire it up and see what happens, but any help gratefully received. Thanks again. Tim Quote Link to comment Share on other sites More sharing options...
Tim Cheal Posted January 30, 2019 Author Share Posted January 30, 2019 So, I got chance to wire it up and see what happens. I stripped off the original power panel wires and put the 2v battery on the back of the terminals and, as expected, all worked well (the plug glows!). But,I now put the ammeter in series and when I connect the glow plug it no longer glows, and the ammeter goes to full deflection. I am guessing that I have taken a resistor out of the circuitry, but no idea which part of the circuit board this is! Does that sound right? Or could it indicate that the ammeter is toast? Or, should I wire it in a specific way? If I need a resistor in the circuit, any advice on size? Sorry about this, electronics is just not my thing! Tim Quote Link to comment Share on other sites More sharing options...
Peter Christy Posted January 30, 2019 Share Posted January 30, 2019 Sounds to me like you've connected the ammeter in parallel with the plug, not in series...... Either that or the meter is not a true ammeter, but had a very low value resistor across it to convert it into an ammeter? -- Pete Quote Link to comment Share on other sites More sharing options...
Nigel R Posted January 30, 2019 Share Posted January 30, 2019 The ammeter in the panel will not have the right shunt for your use. Possibly not even shunted at all. It is also possible the meter has been damaged by connecting directly in circuit with the plug. Two options, first, buy a fresh 5A ammeter. Second, establish what size shunt resistor you need on the meter, by testing the meter to see what current causes full deflection, and then calculating the appropriate shunt. https://www.neatcircuits.com/meter-mult.htm The first will certainly be easier. Quote Link to comment Share on other sites More sharing options...
Tim Cheal Posted January 30, 2019 Author Share Posted January 30, 2019 Thanks both. Nigel, will any 5A ammeter do, e.g. like this one from ebay (costs peanuts, but delivery time is lengthy so don't want to get the wrong thing)? Tim Quote Link to comment Share on other sites More sharing options...
Nigel R Posted January 30, 2019 Share Posted January 30, 2019 That would do it. Looks identical to what I bought for similar purpose. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted January 30, 2019 Share Posted January 30, 2019 You may want to check the shunt is included! Mine had one inside the meter. Quote Link to comment Share on other sites More sharing options...
Tim Cheal Posted January 30, 2019 Author Share Posted January 30, 2019 Thanks Nigel. I found one a bit quicker delivery but couldn’t see any specific mention of a shunt. I’ll take a risk! Tim Quote Link to comment Share on other sites More sharing options...
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