An electric strike lock PCB controls the electrical interface between an access-control system and a door strike mechanism. Depending on the architecture, the board may switch the solenoid coil, protect electronics from inductive energy, monitor door status, regulate power, or provide diagnostics.
A reliable design starts by defining the complete electrical and mechanical boundary: strike model, supply source, cable length, duty cycle, fail behavior, environment, and verification requirements.
Key design decisions before schematic release
| Decision | Required information | Design impact |
|---|---|---|
| Strike interface | Coil voltage, current, resistance, duty cycle, internal suppression | Driver sizing and protection strategy |
| Power source | 12/24 VDC, AC, regulated output, backup battery behavior | Input protection and transient tolerance |
| Lock behavior | Fail safe or fail secure mode | Power-loss state and thermal operation |
| Installation environment | Indoor, outdoor, condensation, vibration, metal frame | Coating, spacing, mechanical design |
| Monitoring | Latch, tamper, door position, supervised contacts | Input protection and filtering |
| Production needs | Functional limits, fixtures, traceability | Manufacturing test design |
Does an electric strike need a local PCB?
A local controller is justified when the system requires controlled switching, diagnostics, protection, or power conversion.
| Architecture | Best fit | Main design concern |
|---|---|---|
| Coil only | Remote controller handles switching | Cable drop and transient location |
| Protected driver PCB | Local MOSFET switching required | Clamp energy and thermal margin |
| Power conversion PCB | Input and coil voltage differ | Efficiency and startup behavior |
| Smart controller | Monitoring and communication required | Firmware recovery and security |
Define which functions belong inside the strike, door frame, access panel, and external controller before layout begins.
How do fail safe and fail secure affect PCB design?
Fail safe generally means the opening unlocks when power is removed. Fail secure generally means the secure side remains locked without power.
These terms describe electrical behavior, not complete safety compliance.
The PCB design must document:
- energized-to-lock or energized-to-unlock operation
- continuous duty capability
- power interruption behavior
- brownout recovery
- mechanical egress requirements
- fire and access-control system interfaces
The exact strike model and installation instructions determine the approved operating mode.
How should the solenoid driver be designed?
The PCB must be designed from measured coil behavior rather than nominal voltage alone.
Characterize:
- coil resistance across temperature
- pull-in current
- holding current
- release time
- startup surge
- repetitive switching frequency
- worst-case cable voltage drop
The switching device requires:
- voltage margin above supply plus transient peak
- continuous current capability
- pulsed current capability
- thermal path evaluation
- gate/base drive suitability
- fault protection
A MOSFET current rating alone does not define safe operation inside a closed door enclosure.
How should inductive kickback protection be selected?
When the solenoid current stops, stored magnetic energy creates a voltage spike. The suppression network determines switch stress and release behavior.
| Protection method | Suitable application | Tradeoff |
|---|---|---|
| Flyback diode | Fixed polarity DC coil | Lower stress but slower release |
| Diode + Zener/TVS | Faster release requirement | Higher switch voltage |
| Bidirectional TVS | Reversing or bipolar systems | Requires waveform validation |
| RC snubber | AC switching applications | Requires tuning |
| MOV | Higher-energy transient environments | Aging characteristics |
The correct choice depends on:
- coil inductance
- switching voltage rating
- harness length
- required release time
- existing strike protection
Measure the voltage waveform at both the switching device and the coil terminals using the production harness.
How should current and thermal performance be verified?
Current capacity depends on temperature rise, voltage drop, copper geometry, enclosure airflow, and duty cycle.
Review these current paths:
- Input connector to protection circuit
- Driver device to coil return
- Clamp-current loop
- Logic supply return
- Chassis or shield connection
Thermal validation should include:
| Condition | Measurement |
|---|---|
| Maximum duty cycle | Switch temperature |
| Maximum input voltage | Coil current |
| Highest ambient temperature | Connector heating |
| Closed enclosure | PCB hot spots |
| Repetitive operation | Thermal drift |
IPC-2152 calculations support design decisions, but the installed assembly determines final performance.
How should status inputs and field wiring be protected?
Door contacts and monitoring circuits often connect through long cables exposed to:
- ESD
- EFT
- surge
- ground differences
- wiring mistakes
Design considerations include:
- input voltage limits
- leakage current
- debounce timing
- filtering
- open/short detection
- connector protection
If the product includes communication functions, review the separate smart lock EMC guide.
What environmental factors affect electric strike PCB reliability?
Door assemblies experience vibration, impact, moisture, cleaning chemicals, and limited airflow.
| Risk | Engineering response |
|---|---|
| Mechanical shock | Secure heavy components and connectors |
| Condensation | Define coating and cleanliness requirements |
| Harness movement | Add strain relief and retention |
| Metal enclosure coupling | Control grounding and spacing |
| Service access | Provide protected connectors and test points |
Conformal coating is requirement-driven. Specify:
- material
- thickness
- keep-outs
- cleaning process
- curing conditions
- inspection criteria
Electric strike PCB verification checklist
| Requirement | Verification evidence |
|---|---|
| Input range | Voltage, current, recovery testing |
| Coil operation | Pull-in and release measurements |
| Driver protection | Switch voltage and clamp waveform |
| Thermal limits | Temperature mapping |
| Monitoring inputs | State and fault testing |
| EMC immunity | ESD/EFT/surge results |
| Mechanical endurance | Powered cycle testing |
| Production quality | Fixture records and traceability |
AOI, X-ray, and electrical continuity tests confirm assembly quality but cannot prove:
- release timing
- door alignment
- environmental durability
- system safety behavior
Electric strike PCB failure analysis
| Failure symptom | Root cause | Verification method |
|---|---|---|
| Driver failure | Insufficient transient protection | Measure switch voltage spike |
| Slow release | Excessive clamp suppression | Compare current decay timing |
| Random resets | Ground bounce or supply disturbance | Probe logic rails |
| False door status | Contact noise or leakage | Test cable faults |
| Field corrosion | Moisture or contamination | Environmental testing |
Electric strike lock PCB RFQ checklist
Electrical information
- Strike manufacturer and part number
- Coil voltage and current
- Fail-safe/fail-secure mode
- Duty cycle
- Internal suppression
- Cable length and gauge
- Supply limitations
PCB manufacturing package
- Gerber, ODB++, or IPC-2581
- Stack-up
- Copper thickness
- Material requirements
- BOM
- Assembly drawings
- Coating requirements
- Test requirements
Verification package
- Functional test limits
- Fixture requirements
- Environmental testing
- Traceability requirements
- First article expectations
- Change-control requirements
Submit requirements through the PCB quote request for manufacturability review.
Standards and responsibility boundary
Depending on product scope, applicable references may include:
- ANSI/BHMA A156.31
- UL 294
- UL 1034
- NFPA 80
- NFPA 101
- IEC 61000-4-2
- IEC 61000-4-4
- IPC-2152
- IPC-A-600
- IPC-A-610
A PCB supplier can provide manufacturing evidence but does not independently create a fire rating, security listing, or system certification.
APTPCB can review submitted requirements through its security equipment PCB workflow.
Electric Strike Lock PCB FAQ
What does an electric strike lock PCB do?
It controls or protects the electrical interface between an access-control system and the strike coil.
Is a flyback diode always required?
No. The correct suppression depends on coil type, release timing, and switching requirements.
Does two-ounce copper guarantee reliability?
No. Current path geometry and thermal validation determine performance.
Is conformal coating mandatory?
No. It depends on environmental requirements and reliability testing.
Can PCB testing prove fire compliance?
No. Fire and access-control ratings apply to evaluated products and installations.
What files are needed for quotation?
Provide PCB fabrication data, BOM, strike specifications, electrical limits, testing requirements, and traceability needs.
Request an electric strike lock PCB review
Submit the released design package, strike information, electrical limits, suppression method, environmental requirements, validation plan, and production quantities.