low temperature, vibration and environment - Page 1
Forum section: electronics / projects

author: bug13
author_rank: Regular Contributor
timestamp: July 26, 2013, 03:05:17 am
content: Hi guysFirst I am new here, I got a few question that I hope I can get some info.What's the effect of vibration on electronics, what I should be aware of? I am talking about electronic on a little rocket that can goes up to 100m/s. Is it going to have a great effect on crystal oscillator etc?What's the effect of low temperature on and what problem I will need to solve, say under -20 degree.Now last one, is there any environment friendly components?I am hoping someone can give me some info on the above, or give me an pointer or something, thanks guys!!Z Wu

author: fcb
author_rank: Super Contributor
timestamp: July 26, 2013, 10:25:53 am
content: Vibration - yes, will have an effect on the frequency of a xtal oscillator - although if it matters is your call, I think you are more likely to kill it than notice the effect - some sort of isolation and mass damping might help.Temperature - just insulate the parts you are bothered about, but in reality (unless you plan on being up there long...) I wouldn't bother.Environment friendly.. do you mean space qualified? $$$$$

author: bug13
author_rank: Regular Contributor
timestamp: July 26, 2013, 09:21:18 pm
content: Quote from: fcb on July 26, 2013, 10:25:53 amHi fcb, thank you for your info, that's helpful.Do you have any info about how many G can kill a xtal oscillator, or is there other type of oscillator that is suitable for this kind of application?about environment friendly, I am not sure if say I throw some transistors and ICs in somewhere in a forest, are they going to be bad for the environment? will they degrade eventually into the environment in a reasonable time? I think that what I wanted to know.Thanks a lot!

author: SeanB
author_rank: Super Contributor
timestamp: July 26, 2013, 09:26:10 pm
content: Vibration means you are going to encapsulate the board after assembly and test in a flexible neutral cure silicone resin, so vibration does not pull parts off the board and they are not solely reliant on the solder for mechanical hold. On a crystal orientation so the leads are in the plane of the force will enable it to withstand the vibration best. You will probably want to have a sleeve of silicone over it as well, or use an oscillator block that does not use a crystal, though those are a little less stable.Temperature means you will insulate so heat loss will not drop you too low before the end of mission ( rocket means up and down in a minute or five, so a simple expanded polystyrene box that is form fitting will do both support and insulation). Battery will likely be a lithium coin cell or a cylindrical cell, choose one with solder tags or PC board mount it inside the insulated box so it will provide best life before it gets too cold. If you have the power a heater will help, but it uses battery power which is extra mass.Environmentally friendly means small, and use lead free solder. You are probably going to lose a few of the modules, so make them small, light and low cost, using plastic chips and ceramic capacitors which will be easy to degrade and which will not leach out heavy metals.

author: bug13
author_rank: Regular Contributor
timestamp: July 28, 2013, 02:50:17 am
content: Quote from: SeanB on July 26, 2013, 09:26:10 pmHi SeanB,Thanks for your explanation, that helps a lot