Leak Detector

[EricPianin]

The leak detector is a circuit used in the event of a leak in the sub. The circuit runs off 5v power. The circuit operates at logic 1, meaning when the sub is dry the circuit generates 0v, and when a leak is detected the circuit generates 5v. Since the mbed prefers 3.3v we have a voltage divider to take 5v down to 3.3v. The current of water is very low, so we need a transistor to amplify this. I chose a Darlington transistor, which is a compound structure containing two bipolar transistors. This allows us to have very high gain so the mbed can read this voltage. I need software to program the mbed to kill the sub when this voltage is detected.

[jchen1]

What port is the leak detector connected to?

[EricPianin]

On 6/17/2013 1:38 PM, Jeff Chen wrote:

What port is the leak detector connected to?

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#17 (comment).

It's connected to pin 20 on the mbed.

[kevin1]

it will be connected to pin 20

[lukeshimanuki]

Are we still using this?

[kevin1]

You should since you guys don't have a double o-ring seal. For testing, it would be good to know if someone messed up when putting the sub back together.