On Sun, 31 Mar 2013 14:38:46 +0100, Andy Burns
wrote:

wrote:

I also use a pair of electro magnets to hold a sliding gate closed

What's the power consumption of that?

They're rated at 500mA but I'm running them on 18V instead of 24V. The
gate opens about 100 times a day so the daily 0.2kWh isn't very
significant.

I went with the magnets rather than the latch for two reasons, it
meant I could have a low closing torque on the motor clutch, and hence
less chance of a crush injury if the optical switches weren't adequate
and so the gate could be manually opened in the event of a power cut,
it's a vehicular access gate rather than a security gate.

AJH