Uploaded May 2026 | Updated September 2026, 1 week ago
A very odd little thing. I initially thought that this was based on a magnetic latching system, but it turns out that it uses a length of a special wire that contracts significantly as it heats up.
It means that this unit is very simple with a minimum of mechanical parts and is not influenced by a strong external magnetic field as some magnetic units are.
The wire is theoretically rated for millions of cycles with this small controlled movement.
Although rated for a higher voltage, I tested this with 1V to slow down the actuator movement.
The electrical data at 1V is:
Cold resistance 2.86 ohms (350mA at 1V).
Hot resistance 2.5 ohms (400mA at 1V).
The unit is normally rated for 3 to 5V.
The unit only energises the wire for the length of time it takes to release the catch, as there is a switch inline with the muscle wire.
As with many items I've been buying recently, this one came from AliExpress (not a sponsor)
Here's a non affiliate link to the listing.
aliexpress.com/item/1005005211494161.html
The cost should be around £2.50, and it may appear as a bundle deal item.
If you enjoy my videos, supporting the channel on Patreon helps keep it independent of YouTube's quirks, avoids intrusive mid-video adverts, gives early access, bonus footage and regular quiet Patreon live streams.
patreon.com/bigclive
Alternatively, for a single coffee contribution you can use PayPal:-
paypal.com/paypalme/bigclive
#ElectronicsCreators
A very odd little thing. I initially thought that this was based on a magnetic latching system, but it turns out that it uses a length of a special wire that contracts significantly as it heats up.
It means that this unit is very simple with a minimum of mechanical parts and is not influenced by a strong external magnetic field as some magnetic units are.
The wire is theoretically rated for millions of cycles with this small controlled movement.
Although rated for a higher voltage, I tested this with 1V to slow down the actuator movement.
The electrical data at 1V is:
Cold resistance 2.86 ohms (350mA at 1V).
Hot resistance 2.5 ohms (400mA at 1V).
The unit is normally rated for 3 to 5V.
The unit only energises the wire for the length of time it takes to release the catch, as there is a switch inline with the muscle wire.
As with many items I've been buying recently, this one came from AliExpress (not a sponsor)
Here's a non affiliate link to the listing.
aliexpress.com/item/1005005211494161.html
The cost should be around £2.50, and it may appear as a bundle deal item.
If you enjoy my videos, supporting the channel on Patreon helps keep it independent of YouTube's quirks, avoids intrusive mid-video adverts, gives early access, bonus footage and regular quiet Patreon live streams.
patreon.com/bigclive
Alternatively, for a single coffee contribution you can use PayPal:-
paypal.com/paypalme/bigclive
#ElectronicsCreators
