Which electronics are pressure sensitive?

Hmm. Thanks for the info – sorry to duplicate post, I had a quick look but didn’t see the other thread.

I didn’t realise the metal cased crystals might be a problem, I’ll have to have a close look at them.

It looks like I’ll have to take a "try it and see" approach! Most manufacturers don’t know if their components are pressure sensitive, so I suppose I’ll have to use common sense and hope for the best.

LEM

Thanks for all the info guys. Bearing all this in mind, I’m about to start soldering up the first board, a computer interface. Its came with a few capacitors, a metal cased timing crystal, some diodes and a load of push switches, all of which I shall be looking at carefully and possibly replacing!

The basic design is coming together a bit now, its pretty clear in my mind. Working to a very tight budget, I’ll have to use mainly off the shelf parts. I’m going to use a very small low power computer as the core. This will control the motors via a USB interface.

I’m planning on using brushless DC motors designed for radio controlled models, which I’ll "marinise" (horrible word) as best I can to prevent shorts and corrosion – I’ll leave them open to the water though, for cooling. The motors need electronic speed controllers, also sourced from remote controlled cars.

Electronics will be housed in an oil-filled compensated epod, as already discussed.

I haven’t settled on camera design yet – I’d like to try making an oil-filled camera, but the optics might be beyond me. Also not sure about fluxgate, depth, altitude and sonar, although the computer interface should allow for all of them. Maybe even a manipulator!

All the data will be piped down a home-made tether (I can’t afford to buy a tether cable) which will initially consist of CAT5 network cable for data, plus some power lines. Control information and sensor data will be passed along the tether digitally, and a laptop computer on the surface, with a standard gaming joystick, will provide controls via custom software.

I’ve got no provision at the moment for LIM or other safety features, so I won’t be flying anywhere sensitive, but maybe in version2….

Chassis, bouyancy, thrusters etc I’ll have to build out of whatever is laying around. I’m concentrating on the electronics at the moment partly because my training is in control systems, but also because I feel they are the most fiddly part, and if I can get them right I can fit them into different body configurations etc.

Hopefully the basic ROV will cost less than 500 pounds sterling in parts… at least, thats the aim!

If anyone has any suggestions or comments I’d very much welcome them. I’d hate to do something through ignorance that threatens the whole project with failure!

Thanks again for your help.

LEM