Ah, I was thinking .1uf because I thought you meant it was for something else.

I was originally thinking an A23 battery. Might be too small though. I'm guessing a pair of 4-pack series AA holders in series would be better?

Yeah the 8 pack of AA batteries would be more likely a winner than the A23. However 2 9V batteries might be better still. I've shorted those out before and measured 5A (for a little bit, then it drops).

 

What about this? - http://1000bulbs.com/product/56368/...BaseShopping&gclid=CLKQhcW_l7ECFUEGRQod11Cjfw


Looks like overkill, but it's rechargeable (right?) and with the charger would still be less than $20. Might save me some dough in the long run, and save some space in the landfill from all the AAs I'd otherwise be going through. What say ye?

 

What about this? - http://1000bulbs.com/product/56368/...BaseShopping&gclid=CLKQhcW_l7ECFUEGRQod11Cjfw


Looks like overkill, but it's rechargeable (right?) and with the charger would still be less than $20. Might save me some dough in the long run, and save some space in the landfill from all the AAs I'd otherwise be going through. What say ye?

it's a winner. No capacitor needed.

 

it's a winner. No capacitor needed.

Excellent! Thanks!

 

While I was sleeping, I remembered where I saw the weak solenoids. Think of a door chime with long brass tubes to make the sound. They use weak solenoids to ping the tubes.

ps, love the battery. It removes all the worry about sufficient power and has a lifetime measured in years. Don't forget to include a connector that can allow power input when the battery dies and the box is still locked! (You might disguise the connector as screw heads.)

 

Don't forget to include a connector that can allow power input when the battery dies and the box is still locked! (You might disguise the connector as screw heads.)

That sounds like the plan I've got for my storage. Sometime in the near future I will be getting a piece of land outside the city and I'll be storing a bunch of my stuff there in a shipping container. I'd like to be able to rest easy, knowing that it's locked with an unbreakable lock from the inside.

I'm planning some solid steel shafts that will slide through holes in the back of the door. They will move by a pneumatic actuator. Pneumatic actuator will be controlled by a solenoid valve inside. both air hose and wires will lead to the outside, disguised, or tucked under the bottom. In order to open it, I show up with a tank of compressed air and a battery. Nobody else would know to look for wires and a hose, and if they found them, they wouldn't know what it's for (hope they don't cut them off).

 

While I was sleeping, I remembered where I saw the weak solenoids. Think of a door chime with long brass tubes to make the sound. They use weak solenoids to ping the tubes.

ps, love the battery. It removes all the worry about sufficient power and has a lifetime measured in years. Don't forget to include a connector that can allow power input when the battery dies and the box is still locked! (You might disguise the connector as screw heads.)

Thanks for the tip! I've been thinking all day of fail-safe methods, as usual I overlooked the easy way.

I've been thinking I could drill through the bottom of the cabinet (there's low shelves there) and hide either a power inlet or something else. It'd be accessible when needed but otherwise hidden.

 

A very different approch: Design the solenoid for 9 volts and bring a 9V battery to open it by touching the battery to the disguised screw heads. That simplifies a LOT of the innards.

 

Ah, that would be a good plan. And would save some money. But I think I'll stick with the 12V design, I want to throw a few other things in there, and they run off 12V. Win win =D

Thanks for the help!