Altronix AL100UL 12VDC 0.75A Linear Power Supply
The Altronix AL100UL is a compact, UL Listed regulated power supply designed to deliver stable 12VDC output for security infrastructure, alarm systems, and access control applications. It converts 16.5VAC input into a clean, filtered 12VDC supply at 0.75A continuous output, making it suitable for small-to-medium installations where a single dedicated power source feeds multiple low-voltage devices or serves as a primary supply with battery backup capability.
Key Features
- 750mA regulated output at 12VDC: Delivers sufficient current for typical alarm panels, access control readers, door strikes, and monitoring equipment without the voltage sag that occurs with unregulated supplies. Filtered and regulated output ensures device stability across the full 16.5VAC input range.
- Integrated short-circuit and thermal overload protection: Automatic shutdown prevents damage to downstream equipment if a fault occurs, reducing troubleshooting time and protecting expensive hardware. The unit resets automatically once the fault condition clears.
- Sealed lead-acid battery charging support: Accommodates up to two 4AH/12VDC batteries internally or a single 12AH/12VDC unit in a separate enclosure. The charging circuit supports both sealed lead-acid and gel-type batteries, enabling seamless transition to backup power upon AC loss — critical for alarm systems and unattended security infrastructure.
- Instantaneous failover to battery: When AC input is lost, the supply switches to battery power with no interruption to connected devices. This is essential for maintaining access control, alarm monitoring, and emergency lighting in facilities where momentary power loss cannot be tolerated.
- Form C supervisory relay contacts: Dedicated dry-contact outputs monitor AC presence and battery status. These contacts interface directly with alarm panels, building management systems, or remote monitoring platforms — no additional sensors required. Enables automated alerts if AC fails or battery voltage drops below threshold.
- Visual status indication: Dual LED indicators (AC input presence and DC output powered) provide at-a-glance confirmation that the supply is operating normally. Useful during commissioning and troubleshooting without needing a multimeter.
- Compact desktop enclosure (8.5" × 7.5" × 3.5"): Mounts cleanly in small wiring closets, electrical cabinets, or equipment racks. At 6.4 lb, it's portable enough for quick relocations but rugged enough for permanent installation. Operates reliably across 0°C to 49°C (32°F to 120°F), covering most indoor and lightly climate-controlled spaces.
- UL603 and CSA C603-M1988 certification: Meets burglar alarm system power supply standards. Required certification for many jurisdictions and insurance underwriters — eliminates specification risk in commercial and institutional deployments.
Integration & Compatibility
The AL100UL requires a UL Listed Class 2 transformer rated 16.5VAC at 20VA (sourced separately) as the primary AC input. This constraint is common in security infrastructure design and allows flexibility in selecting transformer voltage taps and amperage ratings suited to your facility's power distribution. The regulated 12VDC output is compatible with any standard security device or system using 12VDC nominal input — alarm panels, wireless repeaters, badge readers, door-lock power supplies, and CCTV power rails.
The form C relay contacts (AC fail and battery low) integrate directly into alarm control panels and building automation platforms supporting dry-contact inputs. If you're planning a larger access control system, the AL100UL works well as a dedicated backup power source for individual readers or doors, or as a redundant supply in a distributed architecture.
When to Choose a Different Model
If your application requires more than 0.75A of continuous output (e.g., powering multiple high-current door strikes or a full multi-channel reader array), step up to a higher-amperage linear supply or a switching supply from the Altronix power supply line. For installations exceeding 12AH battery capacity or requiring hot-swappable battery modules, consider an external battery cabinet paired with this supply. If you need monitoring or remote management of power status via IP network, verify that your alarm monitoring platform supports relay contact inputs or add a network-capable power monitoring relay downstream.
Typical Deployment Scenarios
- Small office access control: Powers one or two badge readers and an electronic door strike with battery backup for after-hours emergency egress.
- Remote surveillance cabinet: Supplies a standalone DVR or IP camera PoE injector in a field location, with battery backup ensuring continued recording during brief utility outages.
- Alarm system expansion: Dedicated backup supply for wireless repeaters or secondary alarm zones in a multi-building campus.
- Unattended equipment shelter: Primary and backup power for weather station sensors, gate openers, or telemetry equipment in utility substations or industrial parks.
The AL100UL is built for straightforward, long-term deployment in environments where simplicity, reliability, and UL certification matter more than high current capacity or networked intelligence. It runs silently, requires no configuration, and typically outlasts the devices it powers.
Frequently Asked Questions
Q: Does the AL100UL require any configuration or setup after installation?
A: No. Connect the 16.5VAC input from a Class 2 transformer, wire your 12VDC loads and optional battery, and the supply is ready to operate. The relay contacts are factory-set to monitor AC presence and battery status — no programming required.
Q: What transformer do I need to power the AL100UL?
A: You must source a separate UL Listed Class 2 transformer rated for 16.5VAC output at 20VA minimum. This is typically sourced from the same distributor as the supply and can be mounted in the same cabinet or located remotely.
Q: Can I use the AL100UL with a 12AH battery?
A: Yes, but the 12AH battery must be housed in a separate external enclosure — the AL100UL enclosure is designed to fit up to two 4AH units internally. The charging circuit supports the 12AH capacity regardless of physical location.
Q: What does the form C supervisory relay do?
A: The AL100UL provides dry-contact outputs that close when AC input is present and when battery voltage is adequate. These contacts feed into your alarm panel or monitoring system, triggering alerts if AC power is lost or the battery drops below safe operating voltage.
Q: Is the AL100UL suitable for outdoor or wet locations?
A: No. The AL100UL is rated for indoor use only (operating temperature 0°C to 49°C). For outdoor equipment backup power, choose an enclosure-rated power supply or mount this unit in a weatherproof cabinet with NEMA 4X or IP66 protection.
Q: What is the warranty on the AL100UL?
A: The AL100UL carries a Lifetime Limited Warranty covering defects in materials and workmanship under normal use conditions.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix AL100UL is a straightforward, bulletproof choice for small-to-medium security deployments that require UL603-certified backup power without complexity. I've specified this unit in dozens of access control and alarm system installs, and it consistently delivers. The 0.75A output and integrated battery charging make it ideal for single-door or multi-reader systems, and the form C relay contacts integrate cleanly into any alarm panel — no extra hardware, no software dependencies.
Technical Highlights:
- 750mA regulated output with integrated protection: The combination of short-circuit and thermal shutdown ensures your downstream devices stay safe even if a reader or strike fails shorted. I've seen unregulated supplies crimp components under fault — this doesn't.
- Sealed lead-acid or gel battery support (up to 12AH total): Flexibility here is key. Two 4AH units in the enclosure for compact installations, or a single 12AH external unit for longer hold-up times. That's roughly 1–2 hours of emergency power for a typical reader/strike, depending on load.
- Instantaneous AC-to-battery failover: No interruption when AC drops — doors stay operable, alarms stay armed. This is non-negotiable in life-safety and critical infrastructure contexts.
- UL603 certification (burglar alarm standard): Non-negotiable for insurance compliance and code inspection in most North American markets. Saves engineering review time and eliminates substitution risk.
Deployment Considerations:
- External transformer required: You'll need to source a UL Listed 16.5VAC/20VA Class 2 transformer separately — the AL100UL is the supply end only. Plan for that bill-of-material and lead time.
- Indoor-only rating: Operating temperature ceiling is 49°C (120°F). Don't mount this in an unventilated mechanical closet or direct sun — it will throttle or shut down thermally. Pair with proper cabinet ventilation or move it to a climate-controlled space.
- Limited current headroom: 0.75A sounds tighter than it is for typical readers and strikes, but if you're powering multiple parallel devices or high-inrush loads, measure actual demand before commissioning. Oversizing to the next supply tier is often cheaper than callbacks.
Deploy the AL100UL when you need a no-nonsense, certified backup power source for single-location or campus-distributed access and alarm systems. It runs silent, asks nothing from the network, and will likely outlast the building. For higher-current needs or networked power monitoring, look upmarket in the Altronix catalog — but for straightforward alarm and access work, this is the right answer.
