12V Electric Solenoid Door Lock
Fail-secure solenoid lock for DIY access-control projects.
A 12V solenoid lock commonly paired with RFID readers or keypads in DIY smart-lock and access-control builds.
Specifications
| Operating voltage | 12V DC |
| Current draw | ~350-500 mA while energized |
| Lock type | Fail-secure on most DIY-market units — locked when unpowered, unlocks only while energized |
| Duty cycle | Not rated for continuous hold on most models — leaving it energized long-term can overheat the coil, check your specific datasheet |
Pinout
| Pin | Name | Description |
|---|---|---|
| 1 | + | Coil positive lead — through a relay or MOSFET, never straight from a GPIO pin |
| 2 | - | Coil negative lead |
Same inductive-load rules as any solenoid: drive it through a relay or MOSFET with a flyback diode across the coil. Confirm fail-secure vs fail-safe behavior on your specific unit before it goes into a real door.
Variants
Check whether a project actually needs fail-secure (locked when powered off, this listing's default) or fail-safe (unlocked when powered off, required by some fire-egress codes) before wiring anything up — the two behave oppositely and picking the wrong one is a real safety issue on a real door. A DIY servo-driven latch is fine for a prototype or a low-stakes project box lock, but isn't a substitute for a proper solenoid lock or electric strike on an actual access-controlled door.
| Variant | Price |
|---|---|
| 12V solenoid lock, fail-secure (this listing) | ~$5-12 |
| Electric strike (fail-safe or fail-secure) | ~$15-40 |
| Servo-actuated DIY latch | ~$2-5 (servo) |