Altronix AL842LGK Logic Board 24VDC/12A Power Controller
The Altronix AL842LGK is a replacement logic board engineered as the control and regulation core of the AL842ULADA power supply. This component handles firmware-based power distribution, channel supervision, and battery-backup sequencing — the critical functions that keep security infrastructure (cameras, access control, intercoms, strobes) online during mains failure. It's the drop-in repair part for integrators managing installed AL842ULADA systems in multi-output security deployments.
Key Features
- 24VDC / 12A Output: Regulated 24-volt distribution at 12-amp capacity. Supports up to 12 cameras, door strikes, or control devices on a single AL842ULADA frame.
- 12 Supervised Channels: Individual output supervision with AC fail detection. Identifies and logs failed outputs or open-circuit loads without manual inspection.
- AC Fail Relay: Triggers backup power (battery or generator) on mains loss. Designed for 115VAC input — standard North American facility power.
- Battery Backup Support: Firmware coordinates hold-up time and managed shutdown sequencing when operating on backup power. Extends field replacement windows.
- Dual Input Controller (ACMS8CB): Packaged with voltage regulator (VR6) and dual input access controller. Supports mixed AC and battery input sources.
- Lifetime Limited Warranty: Factory repair or replacement at no cost during operational life. Covers manufacturing defects in logic and control circuitry.
- Wall / Pole / Rack Mount: Fits existing AL842ULADA enclosures. No re-mounting or frame modification required on replacement.
- US Manufactured: Domestic sourcing eliminates long lead times on critical repair parts. Warehouse stock available for same-day shipment.
The AL842LGK manages firmware-based logic for power-up sequencing, load-sharing across 12 outputs, and failover coordination. When an AL842ULADA logic board fails (output dropout, AC fail relay hang-up, or supervision loop failure), swapping the board in-field restores the entire supply in under 15 minutes. No re-programming, no re-commissioning — the board is pre-configured for AL842ULADA operation on arrival.
Integration is transparent: the AL842LGK communicates AC fail status via relay contact closure (dry contact) and supervised load status via hardwired indicators. Works with any legacy NVR or alarm panel that accepts relay-based power-supply signaling. No Ethernet, no SNMP, no software dependency — a pure hardwired control solution suited to air-gapped or offline security installations.
Deployment scenarios include multisite shopping centers, parking structures, and access-control hubs where a single AL842ULADA feeds 12 separate zones. When the logic board fails, power to all 12 loads drops — a scenario that costs tens of thousands per hour in lost surveillance and locked doors. The AL842LGK repair part keeps downtime to minutes. For integrators carrying spare boards on service trucks, this is a critical hedge against field failure callbacks and SLA penalties.
The AL842ULADA + AL842LGK combo meets UL and NEC compliance for Class 2 power distribution in security infrastructure. Lifetime warranty on the logic board reflects Altronix engineering confidence in the firmware and control circuitry — a significant cost advantage when factoring repair vs. replacement economics over a 10+ year deployment lifecycle.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
In our experience, the AL842LGK is the hidden lynchpin of multisite security operations using Altronix AL842ULADA supplies. We've seen integrators carry these boards on service vans specifically because a failed logic board strands an entire facility — 12 outputs, zero power — and the SLA clock starts ticking immediately. The beauty of the AL842LGK is not the specs; it's the economics. A replacement board costs a fraction of a new AL842ULADA, and swapping it takes a technician 10 minutes. The lifetime warranty means zero risk on the repair part itself. We've recommended this as a stock item in any integration shop managing 50+ camera deployments across multiple sites. The one caveat: this is a logic board only. You're buying the control brain, not the power transformer or input filter. If your AL842ULADA has a shorted PSU capacitor or a blown transformer, a new logic board won't help — you'll need the full unit. But if the AC fail relay is hanging, or outputs are dropping randomly, or the supervisor isn't communicating load status correctly, this is the surgical fix.
Technical Highlights:
- Firmware-Based Output Supervision: Each of the 12 outputs is monitored continuously. An open-circuit load or short-circuit fault triggers a status relay — no polling required, immediate hardware notification to the alarm panel or control system. That real-time feedback is what lets technicians diagnose problems without a service call.
- AC Fail Relay & Battery Coordination: The AL842LGK detects mains loss within milliseconds and sequences battery backup power. If your facility has a UPS or generator backing the supply, the logic board ensures orderly failover — no brown-out glitches, no missed surveillance during the transition.
- Dual Input Capability (ACMS8CB + VR6): The board ships with both the voltage regulator and dual-input controller. That means the AL842ULADA can accept input from two separate AC sources, or one AC + one battery source. Real-world scenario: a facility with backup generator in a different zone can feed the AL842ULADA directly from the generator on mains loss.
- No Reconfiguration Required: The AL842LGK arrives factory-set for AL842ULADA operation. Swap it into the enclosure, mate the connectors, and power comes back up on the original 12 outputs at their original load-sharing settings. Zero field reprogramming, zero commissioning risk.
- 12A at 24VDC Sustained: Rated for continuous 12-amp draw across all 12 outputs (1A per output max, or concentrated on fewer outputs). That's enough for a mix of high-draw devices (24VDC strobes at 0.5–1A each) and low-draw loads (sensors, relay coils at 0.1–0.2A).
- Lifetime Limited Warranty Covers Logic Faults: Altronix stands behind the firmware and control circuitry. If the board fails due to manufacturing defect, you get a repair or replacement at no cost. That's not common in the OEM parts market and reflects serious confidence in the design.
Deployment Considerations:
- This is a logic board only — it does not include the power transformer, input filter, or enclosure. You must be replacing a board inside an existing AL842ULADA chassis. If the AL842ULADA enclosure itself has failed (burnt transformer, shorted capacitors), you need a full-unit replacement, not this board.
- AC fail relay is a dry contact closure — verify your panel or NVR accepts dry-contact power-supply signaling before ordering. If your system expects Ethernet or serial status, the AL842LGK won't integrate without additional relay-to-Ethernet converters (not supplied).
- Installation is straightforward: kill power to the AL842ULADA, remove the old logic board from its connector socket, seat the new board, and restore AC. No jumper settings, no firmware updates, no downtime for configuration. Typical field replacement time is 10–15 minutes per unit.
- If the AL842ULADA is actively powering a live installation (cameras, strobes, door locks), plan the board swap during a maintenance window or ensure backup power (UPS) is available. The AL842LGK begins supervision immediately on power-up, so there's no warm-up phase — outputs stabilize in seconds.
- Store spare AL842LGK boards in a static-safe bag if not installed immediately. The logic board uses standard CMOS logic and control ICs — standard ESD precautions apply. Don't touch connector pins directly; use the board frame edges during handling.
The AL842LGK is the right choice for integrators maintaining large multisite surveillance and access-control networks where a single power-supply failure cascades into multiple facility outages. Keep these boards in stock, and your service desk will thank you. For more information on compatible Altronix supplies and power-distribution solutions, visit the Altronix catalog.
