Hi,
So this is probably not your run of the mill electronics project for this forum but i thought it might be worth asking as the proportion of smart people here seems pretty high....
I am working on a seismology experiment for a graduate class, the idea is to construct a concrete 2d representational cross section through a volcano. every one else is doing a literature review, and as i can barely read the journals without falling asleep, i wanted to do something different.
So I have constructed a model in concrete, and mounted 24 microphones within the structure. its about 5m wide by 2m high and an inch or so thick, yep its big an' heavy.....
the plan is to then trigger a small explosions (one for each experiment) and record the first arrival times of the pressure wave as it travels through the model. so I now need to record the audio of each of the 24 microphones.... the scale of the model dictates that we need to record in atleast 44khz and preferably 96Khz, now here comes crunch 1) I only have 6 recording channels, 4 at 96khz 2 at 44khz.....
so my plan is to make a switching circuit that cycles through the mic's switching each one on and off at preset times after the explosion in the center. time for an admission, the extent of my electronics knowledge runs out after you get to cheap kit amplifiers from radioshack, I have grand plans and lots of enthusiasm but i think it is safe to say i have little clue what i am doing, so here goes nothing....
I think i can do this using a PIC and a multiplexor, and am working on a design based from what i can gleam from "the art of electronics" which i have checked out from the library, now comes crunch 2) this is that I was going to use a small firecracker to be the explosion, but I realise this will be too dificult to trigger at the right time, and also it is going to be so loud as to saturate the microphones, which are embeded in the concrete..... so does anyone here have any suggestions for an alternative baby explosion source? some one i know suggested blowing up capacitors, but i dont know how practicle that is.... what i need is something that we can trigger from the PIC, and we will then know it takes x milliseconds to detonate, and importantly it will give out a pretty consistent omni direction pressure signal.
Seperately i have writtent a ray tracing computer model which I am going to use to predict/control when to switch between microphones so we allways catch the first arriving wave form.
i have no trouble in coming up with a assembler program to control the PIC i do have issues with thinking/planning how and with which components to switch microphones....
if you think that a little more planning might have been a good plan, you are right, but then wheres the fun in that!
anyway thanks for reading this and i would love to hear any thoughts or suggestions you might have...
cheers
joe
So this is probably not your run of the mill electronics project for this forum but i thought it might be worth asking as the proportion of smart people here seems pretty high....
I am working on a seismology experiment for a graduate class, the idea is to construct a concrete 2d representational cross section through a volcano. every one else is doing a literature review, and as i can barely read the journals without falling asleep, i wanted to do something different.
So I have constructed a model in concrete, and mounted 24 microphones within the structure. its about 5m wide by 2m high and an inch or so thick, yep its big an' heavy.....
the plan is to then trigger a small explosions (one for each experiment) and record the first arrival times of the pressure wave as it travels through the model. so I now need to record the audio of each of the 24 microphones.... the scale of the model dictates that we need to record in atleast 44khz and preferably 96Khz, now here comes crunch 1) I only have 6 recording channels, 4 at 96khz 2 at 44khz.....
so my plan is to make a switching circuit that cycles through the mic's switching each one on and off at preset times after the explosion in the center. time for an admission, the extent of my electronics knowledge runs out after you get to cheap kit amplifiers from radioshack, I have grand plans and lots of enthusiasm but i think it is safe to say i have little clue what i am doing, so here goes nothing....
I think i can do this using a PIC and a multiplexor, and am working on a design based from what i can gleam from "the art of electronics" which i have checked out from the library, now comes crunch 2) this is that I was going to use a small firecracker to be the explosion, but I realise this will be too dificult to trigger at the right time, and also it is going to be so loud as to saturate the microphones, which are embeded in the concrete..... so does anyone here have any suggestions for an alternative baby explosion source? some one i know suggested blowing up capacitors, but i dont know how practicle that is.... what i need is something that we can trigger from the PIC, and we will then know it takes x milliseconds to detonate, and importantly it will give out a pretty consistent omni direction pressure signal.
Seperately i have writtent a ray tracing computer model which I am going to use to predict/control when to switch between microphones so we allways catch the first arriving wave form.
i have no trouble in coming up with a assembler program to control the PIC i do have issues with thinking/planning how and with which components to switch microphones....
if you think that a little more planning might have been a good plan, you are right, but then wheres the fun in that!
anyway thanks for reading this and i would love to hear any thoughts or suggestions you might have...
cheers
joe