DIY electromagnet based time-lock devices

Go 12v.
Most electromagnetic circuits start working at 70-80% of their nominal voltage.
The box you've found is perfect to house a 9v pp3 battery and should run fine.
If you try to get to 24v you will need 2x pp3 to get to 18v and a lot more wiring.
The YouTube videos use ikea batteries and give upwards of 1hr magnetised time from memory

[Like Ra]

I'm going to use accumulators, the voltage is a bit lower, though. As or 24V version, I can use various power supplies (12, 14, 17, 19, 24V). Another possibility is to use 2x 9V batteries in parallel, that should double the bondage time.

If you are using a power supply how will it release?
The YouTube vid rely on battery decay to release.

[Like Ra]

An electronic or mechanical timer. They can be set more precisely, but may stuck, so I use them daisy chained.

[Like Ra]

What is the holding force of two electro-magnets used together? For example, what will I get from two 12V 8mm thick electro-magnets (each has a holding force of 8kg) connected to two 9V accumulators (with reversed polarities)?

I've used EMs a few times... see: https://www.likera.com/forum/mybb/Thread...et-release and https://www.likera.com/forum/mybb/Thread...-time-lock  ...works well for me! 😊

[Like Ra]

Here's a short tutorial (source: https://www.deviantart.com/ropebunnydani...-806789973)

It works 😊
So as you know from my last journal I got hold of an electromagnetic door holder, and immediately decided it would be awesome for selfbondage lol.
So basically heres what it looks like after I modded it -

   

P.S The little switch was an override so you could release the door it held.. I've bypassed it now obviously.. Dont wanna escape too early 😉
I added a ring to the contact and a little hook bracket to the back. As for actually wiring it I just used some cable I had spare. longer the better as it means you can put the timer it will be plugged into out of reach.
Best to use a strong cable too, one that cant be broken by yanking on it. Stuff I used was rubber sheathed pond flex. its plenty tough and really flexible, so great for this job :3

       

The magnet is 24v DC but seems to work fine at 12v DC. (Only DC adaptor I had)

So nows just to find a timer to use with it. Any old plug in timer will work. Although make sure its a decent one that wont fail. In fact use 2 timers in series. So then if one does fail you arent screwd lol.
The magnet is extremely strong. Once its powered and the contact is in place it will not come off until the power is cut. I tried with all my strength (Which isn't much tbh) to pull them apart but it wouldn't budge.
Now all thats left to do is have some fun with it :3

And this is the result (source: https://www.deviantart.com/ropebunnydani...-808630848):

   

As some of you know I recently made a electromagnetic self bondage lock out of an old door holder.

Anyway this is pretty much how my first experiment with it went. I decided to use it as a key drop device, and it works perfectly. When the digital timers not been set up by an idiot that is..
Can anybody see the reason the key didn't drop on time?
remember, when practising self bondage, Always! have a backup way to get out of it :S. So in this case a second timer in series with the first, which thankfully I did have. although it was set for a full 2 hours later
Also this isn't a new OC, its just me in cartoon form lol

BACKUP!!!!

Hello,
I found that which plugs into phone chargers.
https://abcplaisir.com/selfbondage/1575-...-abdl.html

I saw that someone advised to plug it in for the long term.
https://www.amazon.fr/Lifedom-Programmat...4772&psc=1

Can it work without danger for 12h or 20h ?

Thank you for your help.
Sorry for my English, I go through translator

Can it work without danger for 12h or 20h ?

I have one of the mechanical plug in timers that's been running flawlessly for years so yes. I'm not saying you should, only that you can.

[Like Ra]

Oh, I thought this one was posted, but I can't find it anywhere.

   

Source: https://www.deviantart.com/ropebunnydani...-866376925