ElectroMagnetic Release

[chainmaid]

Thought I'd share my my electromagnetic release with you all, hope you find it interesting and maybe useful.

I started with a a 12 volt automotive relay (from Maplin in the UK), a universal low voltage power suppy ( Argos) and a couple of of 24 hour timers:



First thing to do is to carefully hacksaw off the plastic cover to the relay which reveals the coil inside:



Then pull of the relay contacts with a pair of pliers so you just have the solenoid:



Ok, that makes a great electromagnet, now you have to power it. Just wire up the output from the power supply to the contacts for the coil of the solenoid. I used some extra bell wire so that I could have a good distance from the supply to the release.

Next plug the power supply into TWO 24 hour timers plugged into each other and set one timer for the time you want and the other for some time longer. I can't stress how important it is to have two timers, they can and do fail, but the odds against two failing at the same time is high enough for me to risk my life (or should that be reputation?) on.


Then attach the electromagnet above your bondage position, ensure both timers are on and touch your keys to it and they should stick. here's a picture of mine, I added a LED and a 1K resistor wired in series across the contacts , I'll explain why below. If it doesn't light when power is on just reverse the polarity.


Next step is to turn down the voltage on the power supply, notch it down one step at a time until the keys drop, then put it up one more step. The idea is to have just enough voltage to hold the keys, but not so much as to permanently magnetise them. Having them held via a keyring makes this extremely unlikely anyway. In any case test and test again before risking yourself to this.

I usually set a number of different times 2 - 6 hours on main timer and spin it without looking so I have no idea how long it will be. I set the backup to 8 hours and then lock myself fully made up and dressed up in a baby doll, wig, stockings, 5" heels etc in front of a full length mirror. I use a vertical chain fixed to a radiator or the bathroom door hinges with my hands locked around it behind my back and my ankles locked close to it so that I can kneel or stand but not sit.

I've seen some people say bondage without anything extra happening is boring but for me its exquisite. Spending hours on end helplessly locked up with no idea how much time has passed or has left to go is just perfect. My mind runs wild with imagination.
The LED reassures me that the time is not yet up and I will be safely released eventually.

I do this in hotel rooms, in winter I turn off all the heating and open the windows so its cold, in summer its nettle season and I always take a large bagful with me that I use to get my backside very red and sore. Oh - and the nipple clamps of course....

[1azzu1]

sounds like a great way to do it... one question tho... does it matter if its 12V?

[lj]

I'll add a few comments

no, it doesn't matter what voltage the relay is (or any other electromagnet) so long as the voltage is sufficient to make the coil into a magnet with enough strength to hold the item.

Battery power is much safer, batteries always run flat so you have an additional safety release, and you are never in contact with mains electricity.

To prevent the key etc from becoming trapped on the electromagnet, always separate the two with a thin piece of card or something similar. This ensures the release. The key etc may indeed becaome magnetised, but also the pole of the electromagnet can become a permanent magnet over time, albeit a very weak one. The separation means the weak remanent magnetism will be unable to retain the key.

[chainmaid]

The idea is to turn the voltage down until it only just holds the keys.
I have quite a few keys on my ring so they are heavy enough so that when the power goes they are guaranteed to drop. I do like the idea of a piece of card between the key and the electromagnet though if you only have one light key.
Batteries will always run out of power but do they have enough power to hold your key(s) for long enough? and I don't know of any available off the shelf low voltage timer.
I'm an electronics engineer myself and in the distant past I've made timer circuits for release but I'm latterly more comfortable with commercial gear. its a matter of how you view risk I suppose. Two timers in series seems OK to me, I think I take far greater risks when driving or flying.
So I'm comfortable with my release, it works well for me.
I never thought of ice until I came to this site. Its sounds foolproof which is good, but you can't get ice in hotels in the UK

[tkv]

That is my release system described almost precisely. There are just a couple of differences.

- I use two six hour countdown timers in series, that simply stop and turn off after they've reached the set time.
- My magnet is a solenoid from an old VCR.

Using an automotive relay was clever, they are a lot easier to come by than scavenging stuff from old electronics. Good idea.

[Derek]

think i might try to build a release device like this.. but with the relay glued to a bathroom fan timer, and have a 9v or a 9.6v battery attached to it as well.. so it is completely portable and can be basicly attached to any wall or ceiling...