BAZ Posted January 26, 2014 Share Posted January 26, 2014 I have got fed up of holding my red light torch at the front of the mount to try and illuminate the constellations, and more importantly, the circle markings in the polar scope. So I thought I would have a bash at making one out of bits I had knocking about down the shed. I started out with a 12v red LED, but this was way too bright, so using a variable transformer, found 3v just got it lit. I tried a 1.5v battery, but it didn't have enough go in it. So with a switch from an under cupboard light which had gone south, a small project box, a AAA battery holder, and a bit of heat shrink off we went. I had to go to Block and Quail, (B&Q) for the 32mm stop end, which with one wrap of tape will fit spot on. Here's the result. If t needs dimming further, then I will have to remove more material from the stop end, I drilled a 20mm hole in it, removing more plastic will stop light reflecting down the polar scope. Link to comment Share on other sites More sharing options...
Daz Type-R Posted January 26, 2014 Share Posted January 26, 2014 Nice one ! Link to comment Share on other sites More sharing options...
xanthic Posted January 26, 2014 Share Posted January 26, 2014 Nice job. It'd be easier to put a variable resistor in to limit the current and dim the LED though. I've got plenty that'd be suitable if you want me to send one your way. Link to comment Share on other sites More sharing options...
BAZ Posted January 26, 2014 Author Share Posted January 26, 2014 I thought of a variable resistor, but there's no room in the box for it. If I need to, I'll stick a fixed one in the line. It may take a bit of mucking about to get the right value, but once I have found it, I'll post it here. Link to comment Share on other sites More sharing options...
+RonC Posted January 26, 2014 Share Posted January 26, 2014 Nice one Martyn Link to comment Share on other sites More sharing options...
BAZ Posted January 26, 2014 Author Share Posted January 26, 2014 Once I have field tested it, I'll put up the list of ingredients, or will build them for cost of parts, plus a small fee payable to EMS funds. Link to comment Share on other sites More sharing options...
dawson Posted January 26, 2014 Share Posted January 26, 2014 Very clever. Can you knock me up an obsy now please Martyn JD Link to comment Share on other sites More sharing options...
xanthic Posted January 26, 2014 Share Posted January 26, 2014 (edited) Would one of these fit inside the box? Edited January 26, 2014 by xanthic Link to comment Share on other sites More sharing options...
catman161 Posted January 26, 2014 Share Posted January 26, 2014 Very nicely done as usual Martyn. You always do DIY to such a good standard Link to comment Share on other sites More sharing options...
+RonC Posted January 26, 2014 Share Posted January 26, 2014 Just made mine! Used an old SW polarscope LED and box (with a variable Pot) good idea!! Link to comment Share on other sites More sharing options...
Cazz Posted January 26, 2014 Share Posted January 26, 2014 Very clever and tidy Martyn. :-) Link to comment Share on other sites More sharing options...
catman161 Posted January 28, 2014 Share Posted January 28, 2014 Hey Martyn, I want to try and do something similar for my finder scope. So far I've messed about this evening but can't even get a PP3 battery to light an LED! I'm not sure if there needs to be a resistor in there somewhere. Below is a picture-I'm sure it's my lack of knowledge and skill. What Id like is to find a variable pot box (if they exist) and wire it up so that I can adjust the brightness. Link to comment Share on other sites More sharing options...
Brantuk Posted January 28, 2014 Share Posted January 28, 2014 I got my pot from Maplins Felix - the one on the Lightbridge for varying the fan speed if you remember. Link to comment Share on other sites More sharing options...
catman161 Posted January 28, 2014 Share Posted January 28, 2014 I was in maplins today but couldn't find one! Link to comment Share on other sites More sharing options...
xanthic Posted January 28, 2014 Share Posted January 28, 2014 Hi Felix - don't connect an LED straight to the battery, it'll likely just burn out. You want a resistor on it to control the current. Closest standard one I can see is 820 ohm, though you may want it a bit higher if the LED is too bright. I'm happy to put the bits in the post if you want. Link to comment Share on other sites More sharing options...
catman161 Posted January 28, 2014 Share Posted January 28, 2014 Thanks Leigh what I'm hoping to be able to do is make it so that I have a small battery box like in the picture then a knob that I can turn to adjust te brightness of the LED-do you think that's possible? Link to comment Share on other sites More sharing options...
xanthic Posted January 28, 2014 Share Posted January 28, 2014 (edited) If you add a 5000 (5k) ohm potentiometer (variable resistor) to the 820 ohm, you should be ok. Edited January 29, 2014 by xanthic Link to comment Share on other sites More sharing options...
philjay Posted January 29, 2014 Share Posted January 29, 2014 Very nifty Martyn. Just like me, I wander around diy places looking at what can be utillised for astro Link to comment Share on other sites More sharing options...
catman161 Posted January 29, 2014 Share Posted January 29, 2014 If you add a 500 ohm potentiometer (variable resistor) to the 820 ohm, you should be ok. Thanks Leigh. I think I am gonna have to do some reading. Until last night I had not heard of a "breadboard" when it comes to electronics! Link to comment Share on other sites More sharing options...
xanthic Posted January 29, 2014 Share Posted January 29, 2014 I've just realised I'd dropped a zero on the resistance of the pot in post above. Yes, get a breadboard to test these things out. It does make life a bit easier and saves desoldering when you realise you've done it wrong. Link to comment Share on other sites More sharing options...
catman161 Posted January 29, 2014 Share Posted January 29, 2014 Right so a breadboard is just for testing the circuit then and you then solder it all up in a project box?? Man I think this is way above my capabilities! I don't mind learning it I just want to make sure I do it correctly! Link to comment Share on other sites More sharing options...
Guest Kheldar Posted January 29, 2014 Share Posted January 29, 2014 Right so a breadboard is just for testing the circuit then and you then solder it all up in a project box?? Man I think this is way above my capabilities! I don't mind learning it I just want to make sure I do it correctly! If you can do the NEQ6 power mod, you can do this Link to comment Share on other sites More sharing options...
xanthic Posted January 29, 2014 Share Posted January 29, 2014 If you can do the NEQ6 power mod, you can do this Indeed Link to comment Share on other sites More sharing options...
catman161 Posted January 29, 2014 Share Posted January 29, 2014 Ha ha! Thanks for the vote of confidence guys. One thing I don't get though is if you look at this picture of the circuit on the breadboard-how then do I join it all together without the breadboard? Do I just solder it all together in a line or is there some sort of different board that I mount all the components on and solder them (somehow!) together on that?? Sorry for the thread hijack btw Martyn! Link to comment Share on other sites More sharing options...
Guest Kheldar Posted January 29, 2014 Share Posted January 29, 2014 From breadboard to stripboard - something like this - http://www.maplin.co.uk/p/stripboard-fl17t Or just be hardcore and let it all rattle around loose Link to comment Share on other sites More sharing options...
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