optical cable

[Henning]

Hello !
i'm interrested in sss and i' have some questions:
there are several sss available,with the towfish only connected to the ship by one 3.2 mm optical cable.how is this possible ,because i need a lot of power to feed the transducers and its not possible to deliver `ampere `through an optical cable but only the data.do this type of towfishes work with battery or how do they get enough power?
and how many power is typically need ? i read that
they work with short peaks of about 2000 watts but whats the average power for an amplifier for 200 khz and 100 m cable ?
more questions will follow !
Thank You
Henning,Bremen

[PeterM]

Re: optical cable

Hi Henning,

With piezocheramics I think you want lots of volts and not lots of amperage. You can easily make lots of volts from a small battery which I guess is the case with commercial sss systems.
My guess would be that the optical cable is only for data transmission and that the power supply is onboard the towfish.

regards,
PeterM

[Fergus]

Re: optical cable

>Hi Henning,

>With piezocheramics I think you want lots of volts and not lots of amperage. You can easily make lots of volts from a small battery which I guess is the case with commercial sss systems.
>My guess would be that the optical cable is only for data transmission and that the power supply is onboard the towfish.

>regards,
>PeterM

Hi Henning

Peter is correct, that it is a high voltage that works the transducer. It is in effect reversing the piezo electric effect - where a voltage is generated across a material which is stressed/strained. The voltage appears across faces at 90 degress to the load. This being the case a high voltage can be generated without drawing much current. Electrically speaking you can have a high potential, but with no (in theory)current flow.

As you may know from piezo gas lighters the voltage is obviously very high to get an arc across a gap of several mm. So you can see the potential (ho ho) issues in reversing this effect.

SSS systems such as the CMAX CM800 use internal batteries (in the fish) and send data via a fibre optic umbilical.

best regards

Fergus