Daz69

Hi Gina. Where would an absolute newb start with these Raspberry Pi's? This all looks extremely technical and scares the jeepers out of me even wanting to begin to learn how these things work. I see so many people use these for all sorts of projects, so they are clearly versatile devices, and I would love to bring one into my projects. I'm just feeling like its all way above my head.

Thanks for the link, found some on the bay with delivery by Wednesday, fed up with China Post.

A nice tidy build, well done. I'm starting my distribution box build today. Delivery from China is a right PITA isn't it. Sometimes you feel it's worth spending a few quid more just to get it from the UK to speed things up. I waited ages for my PWM's from China too. Where did you find the fuse holders? Daz

Thanks Dave, much appreciated. My dimmers finally arrived today from China, via Saturn I think! I believe I have everything I need now, so construction will begin probably on Sunday when I'm off. I just stripped down the dimmers and boy is that a small PCB, which is great as it won't take up any room at all, very happy!

I like this idea very much. My 2 converters arrived today, and boy are they small! I'm happy to fit the bucks inside my main box as I'm also doing the crowbar circuit to protect the camera as well, and perhaps I'll just make a straight-through wire from my box to the camera using this battery dummy. As stated above, does this dummy give you the error message described? Many thanks!

Hi Gina. Thought about that but want to still be able to use it on days out etc, so it needs to be removable. Around the manufacturers joint? Understood.

How did you break into the battery?

Yep, much cheaper option!

One further question at this stage, Sorry I have asked a lot lately, but with the power for the camera, will I need one of those dummy batteries or do I use the small USB socket? I cannot find my manual, think my son has borrowed it when he used my camera for his media project.

I have loads of those for my RC planes, right up to 6s 5000mah! The camera will be powered by my home made 12v power supply. It will have 2x 12v RCA sockets, 9v RCA for a rear fan, 2x adjustable PWM channels for heater bands, 2x adjustable voltage sockets using buck converters and LED displays (one will be for my camera which will have voltage protection as mentioned above), 5v RCA sockets and 2 cigarette sockets. Initially I will only use a 9Ah deep cycle battery to fit the project box that I have, more of a trial really, but if I find a larger project box then this will house 2 of them, and a PSU for home use, that I took out of an old PC. I've been looking at those heavy duty battery boxes for leisure batteries perhaps. I'll never use all of these sockets at the same time, well at the mo. I'll likely only use 2x heater bands for EP and secondary, fan and camera. I might include 2x USB sockets for tablet and phone, or just use one of those cigarette socket USB plugs. My end vision is to have a small observatory where I can use this set up. Mrs Daz has giving me permission to build one. She mentioned it once in a conversation. That's permission, isn't it?

I agree. I tried searching but Canon specs aren't great, and other Google searches threw up anything between 6.5v and 8.5v which seemed nothing more than guesses, so originally I went with the 7.4v shown on the standard battery pack. I know that the camera is too heavy for the focus tube on my scope so my intention was to just use it with my 300ml lens on the tube ring mount.

I see that the recommended external battery pack is exactly as you say, 9v, so I have gone for a circuit that will shut down at 9.1v as shown in the above link (now fixed!). Having had this bought for me a couple of years ago by Mrs Daz as a "get well" present, and then finding the receipt (she also got me 2 extra lenses 18-135mm and 70-300mm), I want to protect it as much as possible, as I know I won't be getting another one in a hurry I went and bought the components from Maplin, luckily I got a nice chap who knew what I wanted to build, as sometimes it can be a bit of a gamble with their staff. Hoping that all of my other bits n' bobs will turn up before Sunday as I have 5 days off and want to get the whole project built. Thanks again.

Moving on, @Davey-T has given me a good idea in incorporating a seemingly obvious safety net of a so-called crowbar circuit, ensuring the voltage doesn't suddenly spike or rise should the buck converter fail, and saving my camera. Here is a 9.1v crowbar circuit diagram, but I'm stuck (again) on some of the values. I read that the circuit should be around 1v more than the operating voltage requires, so going with what others have said so far, this 9.1v circuit should fit the bill nicely. My issues are with the Schottky diode and the thyristor values. Also, would the 0.25a (250mA) fuse be enough? Here is a link to the page where I found it: https://en.wikibooks.org/wiki/Practical_Electronics/Crowbar_circuit Thanks again guys n' gals.

I don't, just have the standard battery. It's all good info so thanks for taking the time to assist me.

I presumed 7.4v as that's what's in the specs, but it seems that is not the case. I ordered a couple of the buck converters to see how good they are. I have some small red LED voltage displays that I'll use on the outside of the box, but I'll check the outputs firstly with my multimeter. Thanks for all of your replies, really helpful, especially as I'd never seen these converters!