Altronix SMP312C Single-Output Power Supply/Charger
The Altronix SMP312C is a compact board-level power supply and charger for low-power security and access control applications. It accepts flexible 12–28VAC input—useful when your building's existing transformer runs anywhere in that range—and delivers selectable DC output at 6, 12, or 24VDC. The selectable voltage feature eliminates the need to stock multiple SKUs; you can configure the output voltage to match whatever your connected device requires. The integrated BT124 battery backup module means the supply continues to power critical loads like door locks or readers during AC mains loss—a real operational requirement in access control deployments.
Key Features
- Selectable Output Voltage (6, 12, or 24VDC): Configure the output to match your specific access control or sensor requirement. No need to carry three different part numbers for different voltage tiers.
- 0.5A Maximum Output Current: Sufficient for auxiliary power to a single electronic door lock, magnetic lock, or small sensor/detector array. If you need higher current for multiple locks or high-draw readers, plan for a higher-capacity supply or distributed power architecture.
- Wide Input Range (12–28VAC): Accepts voltage from nearly any building transformer, reducing installation constraints and making replacement or upgrade simpler when existing wiring is already in place.
- Integrated BT124 Battery Backup: Included battery module ensures seamless failover during power loss. No separate battery enclosure or charger card to wire; backup is built in.
- Board-Mount Form Factor: Designed for integration into control panels, distribution boards, or equipment racks. Compact footprint keeps overall panel real estate minimal—critical in retrofit or space-constrained installations.
- Lifetime Limited Warranty: OEM backing for long-term peace of mind in fixed installations where replacement downtime is costly.
Typical Applications
The SMP312C works well as an auxiliary power source in access control systems—powering badge readers, door strike solenoids, or magnetic locks that draw less than 500 mA. It's also suited for backup power to small sensor networks, call boxes, or standalone charger duty for portable security equipment that runs on 6, 12, or 24VDC. Because the output is selectable at configuration, you can use a single supply model across projects with different voltage requirements.
Integration & Compatibility
The SMP312C is designed for integration into larger access control systems where it functions as a dedicated auxiliary power module. Its board-mount design allows panel installers to wire it inline with existing 12–28VAC distribution. The BT124 battery backup provides uninterruptible power to the selected load—meaning your lock, reader, or sensor does not drop power during a utility outage or circuit interruption. Ensure your control panel design accounts for the 0.5A per-output limit; loads exceeding this current will require a higher-capacity supply or parallel modules.
When to Choose a Different Model
If your access control installation requires multiple independently powered outputs—such as separate supplies for different zones or reader types—or if any single output must deliver more than 0.5A, evaluate a higher-current or multi-output power supply from the Altronix product family. If you need DC-to-DC conversion without battery backup, a simpler non-backed-up supply may reduce cost. For applications where AC input voltage falls below 12VAC or exceeds 28VAC, confirm your transformer rating before specifying the SMP312C.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix SMP312C is a straightforward, board-level solution for auxiliary power in access control—nothing flashy, but purposeful. The selectable output voltage (6, 12, or 24VDC) and integrated BT124 battery backup module cover the majority of small-scale lock and reader power scenarios, and the wide 12–28VAC input range makes it adaptable to existing building infrastructure.
Technical Highlights:
- 0.5A Output Current: Adequate for a single electromagnetic or electronic lock, or small battery of sensors—but not for high-current readers or multi-lock arrays. Know your load before specifying.
- Integrated BT124 Backup: Battery module is included, not sold separately, and handles failover without additional wiring. Eliminates a separate backup charger board in many access control designs.
- Flexible Input Voltage (12–28VAC): No need to specify a transformer upgrade; works with most standard building transformers in that window. Simplifies field retrofits.
Deployment Considerations:
- Current Limit Is Real: The 0.5A ceiling is a firm constraint. If your lock or reader pulls 600 mA, this supply will not carry it reliably. Size your load carefully or plan for a higher-capacity Altronix supply.
- Board-Mount Integration: This is not a standalone wall-mounted supply. It requires panel mounting, proper wiring, and integration into a control enclosure. Installers must be comfortable with board-level assembly.
Deploy the SMP312C in small-to-medium access control systems where a single door or reader zone needs reliable, battery-backed auxiliary power. Pair it with a compatible Altronix control panel and your chosen readers and locks to build a compact, integrated solution. It's not the supply for a 16-door enterprise system—that demands a larger architecture—but for a single-zone retrofit or auxiliary backup in a distributed control setup, it delivers solid, proven performance.
Frequently Asked Questions
Q: What's included with the SMP312C, and do I need to buy the BT124 battery module separately?
A: The BT124 battery backup module is included with the SMP312C. You do not need to purchase it separately. It is pre-integrated and ready to provide backup power during AC mains loss.
Q: Can I configure the SMP312C output voltage after installation, or is it set at the factory?
A: The output voltage (6, 12, or 24VDC) is selectable, but configuration details are typically set during board installation. Consult the product datasheet or contact Altronix technical support if you need to change the output voltage after the unit is wired into your panel.
Q: Will the SMP312C work with my 10VAC transformer?
A: No. The SMP312C requires 12–28VAC input. If your transformer is rated below 12VAC or above 28VAC, it is not compatible with this supply. Verify your building transformer voltage before specifying the SMP312C.
Q: What happens to my connected lock or reader if the AC power fails?
A: The integrated BT124 battery backup module takes over automatically, continuing to supply power to the selected output without interruption. This ensures that your door lock, reader, or sensor remains powered during a utility outage or circuit fault, provided the battery is charged.
Q: Is 0.5A enough to power my electronic door lock?
A: Most electronic locks draw between 200 mA and 500 mA, so a single lock can be powered by the SMP312C. However, if your lock or reader draws more than 0.5A, the SMP312C will not reliably supply it. Always check your lock or reader datasheet for current consumption and confirm it falls within the 0.5A limit.
Q: Does the SMP312C include any mounting hardware or brackets?
A: The SMP312C is a board-mount component designed for installation inside a control panel or enclosure. It does not come with wall-mount brackets or standalone housing. Installers must integrate it into their panel design using the appropriate mounting method for their control board.
