Tuesday, 30 April 2013

Why We Test

The Magic of FETs

I've never had a lot to do with FETs before so I've been keen to experiment with and learn about FETs on my home projects.

As I wrote before in Basic Protection I like the simplicity of using a P-FET to provide reverse bias protection, and with my Alarm Interface I was planning on combining this reverse bias protection with current limiting.

As usual, I got it wrong the first time....

Thursday, 4 April 2013

Cutting out the Middle Man

Home Alarm Monitoring

I have a home alarm system, and it's reliable and the monitoring company provides a good service.  For a bit less that a dollar a day, if the alarm goes off, they give me a call.  

Each and every time it goes off.  

My system has multiple zones, and my thinking is that if only the one zone is triggered, it's probably not a burglar in the house.  And I don't want my long weekend away spoiled by my wife continuously worrying about the single zone alarm that went off 2 hours ago and we are not going to be home for two more days.

I've requested with the monitoring company to *not* call me when it's only one zone, but policy is policy and they need to call.  Fair enough.