Switching Relay Output using Audio Signal

Audio Controlled Relay ST-ACR1


  • Switching Controlled by Audio Signal
  • Switching from Mic or Line Signals
  • Silence Sensing
  • DPST switching relay output
  • Open-collector slave output

Connection Setup

Audio input, Light output
Alarm signal trigger system

Device Wiring Connection

Audio wiring input connection

The module uses 24Vdc for powering up the audio sensing input and relay output.

Power supply connection

Manual input to control the output relay.

Adding manual control

You can purchase the module ST-LCR1 to extend out for more relay outputs.

Adding more relay output for interfacing to external system.


  • Audio input: 10Kohm balanced bridging
  • Input connections: may be connected balanced or unbalanced
  • Control output: open-collectpr @ 25mA
  • Retrigger delay: 250ms
  • Relay output DPDT (up to 230Vac, 2A)
  • Activation response time: 25ms
  • Dimension: 17 x 76 x 39mm


Product dimension size

Size Dimension

Audio Controlled Relays (other models)

ST-ACR1 Audio Controlled Relay

Relay is actuated by audio line level source.

ST-ACR1M Audio Controlled Relay

Relay is actuated by microphone input source.

ST-ACR2 Audio Controlled Relay

Can be used as a silence sensor detection device. Relay release delay is extended by 5-50sec.

ST-LCR1 Logic Controlled Relay

Logic controlled relay. Relay output is DPDT (dual pole dual throw)

ST-LCR2 Logic Controlled Relay

Pulsed controlled relay. Relay output is DPDT (dual pole dual throw)

ST-VOX1 Voice Activated Relay

Voice controlled relay output. Input voice can be from microphone or audio line level. Can be used in a voice intercom setup.


Audio Activated Relay PIC-125

Click here to but Audio Activated Relay [PIC-125] product.

Touchless Lighting Wall Switch

Touch-less lighting wall switch. Switch On/Off your room lighting without touching the wall switch.

Suitable for installation at public area or high traffic user premises.

Reduce germs bacteria virus condemnation.
Minimise touch surface that can have direct contact with Covid virus.

Touchless Lighting Wall Switch
Video Demonstration

Build-in electronic IR sensor is sensitive to hand activation on the wall switch. Wave one time to turn on the lights and wave again to turn it off.

Simple and sensitive touchless hand wave wall switch sensor. Very simple to use.

Contact us at sales@pic-control.com for further information.

Check out our series of touchless contactless electronic wall switches for your other application.

Shutter Control with Rain Sensor

No more worrying about the rain.

Use a rain sensor to automatic control your motorised roller shutter control to prevent rain water from splashing into your premises.

Rain Sensor

This rain sensor requires little maintenance as there are no mechanical parts or metal part that is expose to the wet environment.

The electronics is seal in a clear water-proof dome shape enclosure.

Simple sensor to detect and control your shutter.

Click here for more information about this rain sensor.

Motorised Roller Shutter Control

This is a 230Vac motorised roller shutter installed in a kitchen of the HDB flat. The shutter is open to allow natural air breeze to come in. When it rains, this shutter is automatically closed with the help of the rain sensor and a controller.

Shutter Open

Shutter open

Open shutter door to allow fresh air and breeze into the house.

Shutter Close

Shutter close

Shutter is automatically closed when rain water drops is detected by the rain sensor which is installed right outside this shutter.

Rain sensor mounted outside the window grill.

Wall Switch for Shutter

Wall switch for manual overwrite of the roller shutter up/down control

Manual Mode

The user can use the wall switch to manually control the shutter by pressing the up or down switch.

Auto Mode

Leaving the switch in the middle will leave the system in the automatic mode. This means the rain sensor will be in control.

When it rains, the sensor will close the shutter. When there is no rain for a period of time, the sensor will automatically open the shutter.

Rain Sensor Controller

Controller for Raini Sensor

A rain sensor controller interface between the rain sensor, the motorised roller shutter, the wall switch control panel and the electricity power.

For more information about this rain sensor controller, please click here.

Rain Sensor Installation Photos

Depending on how fast you want the sensor to be activated, the sensitivity of the sensor can be adjusted. In typical installation, we will set it to the most sensitive.

A custom mounting bracket can be use to extend out the sensor. This will help the sensor to activate the shutter close earlier before the rain gets splash into your home.

Rain sensor is extended out from the wall to detect the rain outside.
Robust rain sensor under the hot sun.

Relevant Post

Sound Audio Detector

A “Sound Audio Detector” is a device or software application designed to detect, analyze, and sometimes interpret sounds within its vicinity. These detectors are utilized in various fields for a multitude of purposes, ranging from security and surveillance to scientific research and entertainment.

Audio detector detects audio sound from an audio input and switch on a relay output. The relay can be used as an output to trigger/switch on devices like light indicators, motors, lock and other electrical appliances.

Detector can detect signal from an audio line input, and convert it into an relay output to switch on another appliances/system in a very quiet environment or a very noisy zone.

This alternative notification provides an additional means of alarm alert for the users or operators.


  • Detects audio and trigger output in a quiet environment.
  • Alarm alert for hearing impaired individual
  • Convert audio alarm into other forms of alert notification in a very noisy environment.
  • Security and Surveillance: Sound detectors are commonly used in security systems to identify and alert operators to potential threats or unauthorized activities. They can recognize sounds such as breaking glass, footsteps, or alarms.
  • Environmental Monitoring: In scientific research and environmental monitoring, sound detectors are employed to track wildlife activity, measure noise pollution levels, and monitor natural phenomena like earthquakes or volcanic eruptions.
  • Industrial Applications: Sound detectors play a crucial role in quality control processes within industries. They can detect abnormal sounds in machinery, indicating potential malfunctions or maintenance needs.
  • Smart Homes: Integrated into smart home systems, sound detectors can recognize voice commands for home automation or security purposes.
  • Entertainment: Sound detectors are utilized in interactive installations, gaming, and virtual reality applications to enhance user experiences by responding to specific sounds or creating immersive audio environments.


In essence, sound audio detectors serve as valuable tools across a diverse array of fields, offering real-time monitoring, analysis, and interpretation of sound data for various applications, from security and surveillance to scientific research and entertainment.

This is a general purpose audio detector.

Click on this link for more information about this audio detector device.

For customised detector, feel free to contact PIC-CONTROL.

Automatic Identify Cable Connection | Wiring Trace & Map Productivity Tool

Are you looking for a tools that can help you identify and trace out the connection from your complex chunck of cable & harnesses with a press of a button?

Get hold of this awesome engineering tool for your electronic lab.

This tester maps out the connection of your cable saving you time and provide you with accurate results.


  • Generate a comprehesive pin to pin connection report.
  • Fast.
  • Accurate connectivity report.
  • No more human error in your diagnosing of the cable wires connection.
  • Decide complex wiring connection.

Examine the pin connection at a glance through the generated mapped connection report.

Automatically mapped out all the wiring on the cable for you. You do not have to trace each pin connection one by one. You will get instant result through the generated test report.

No matter how complex your cable or harnesses is, the process of decoding your wire connection is still the same.

Simply connect each connector pin wire to one of the terminal on the PIC-350 connection decoder, it will automatically trace, identify and mapped out all the connection for you.

The only thing you need to do it to analyse the generated report and document the results.

Simple. No more painstaking connection measurement, checking pin by pin manually using a multimeter.

PIC-350 is an awesome and smart X-ray tool for your cable wires reverse engineering work.

A productivity tool that an electronic engineer will keep on their engineering work bench.

A great tool to discovery the connection of a new or unknown cable. Can also be use for trace passive connection on your PCB circuit board.

– Cable connection reverse engineer tools
– Cable connection tracer, mapping
– Auto mapping of complex cable wiring connection.
– Auto detection of wiring connection



Check out more information about this cable connection analyser product PIC-350.

Hotel Card Key Switch

Contactless Card Key Switch for
Hotel, Dormitory or Rental Room

This card key switch is designed to be activated by a contactless card. Only a contactless card can activate this switch for powering up the electrical system in a room. A normal card cannot trigger this card key

contactless hotel card key holder

Blue Glow Indicating Card Key Holder

Card key holder will glow softly in the dark to guide the guest to slot in their contactless card key.

The relay switch gets activated to turn on external power control system. The power system will switch on the electrical system in the room.


blue glowing hotel card key switch

Key Card Switch operated by RFID electronic circuit

Custom RFID reader circuit for hotel card key

RFID Switch BMS-RFS001-V1 circuit board for hotel card keyRFID Switch BMS-RF001-V1


RFID Switch product by PLC Systems Technik, Philippines

Note: Please take note that this is only the key card holder to detect the contactless card. It cannot be used to power up your electrical appliance. External power control system is required to power up the rest of the electrical appliances within the room. The following examples of high current appliances have to be powered up by an external interface.

  • Aircon
  • Lightings in the room
  • Heater
  • Fridge
  • TV
  • etc…

Other Custom RFID Products


Water Leakage Sensor

This page explores the various type of water sensor for the detecting of water leakage. These sensors are commonly used to detect or monitoring of water leakage from aircon condensation.

Aircon condensation water leakage is a very common sight in the industry. This problem is normally due to improper design and installation of the water drainage pipes. Water drainage pipes installed were too small resulting in water clogged by dust or mould when used over time. Some water drainage pipe was seen to be installed in a anti-gravity manner, which makes it impossible for any water to drain out.

->> Click here to learn more other problem relating to aircon water leakage.

It is important to ensure how these pipes are deployed during the installation process so that you will not be faced with water leakage issues.

If you are already facing the problem, consider reconstructing your water drainage system or implement the following sensor to reduce your trouble.

Aqua Switch Water Sensor

AquaBlock or Aqua switch is installed in water tray for detecting of water leak from aircon or pipes. It can also be mounted at a specific height in the tank to detect water level. The aqua switch is only a block and does not have any moving parts.

Click here to buy Aqua Switch water leakage detector sensor online.


Aqua Switch

Aqua Block

The sensor is a simple relay switch which will activate when water touches the sensor block. It can also be used as a water level detector when mounted at a certain height.


  • No moving mechanical parts
  • Relay output (dry contact switch output)
  • Simple to install
  • Suitable for aircon water leaking detection

Click here for more detailed information of this Aquaswitch water detector sensor.

Or you can also click here to buy Aqua switch sensor.

Water Leak Sensor Cable

This sensor looks like a yellow cable or rope. This sensor cable is typically laid on the floor or above the ceiling to detect water leakage. Any water touching this water sensor can be detected by the connected electronic sensor box. The cable can be place where water leakage is likely to be found.

This type of sensor cable is commonly deployed in computer server room where there are many aircon system installed. Aircon leak is a common problem in a server room.

Other Type of Water Sensors

Check out our other pages for more water sensing technology.

Contact PIC-CONTROL for further information.

Short Circuit Alarm

A short circuit can happen which can interrupt your equipment or other electronic devices.

Custom Short Circuit Alarm

We can custom design short-circuit detector to sense any abnormal condition and trigger an alarm alert.


Check out our custom electronic design service or contact PIC-CONTROL for more information.

High Voltage Measurement Probe Circuit

High voltage electrical pulse probe measurement

High Voltage Electrical Pulse Probe Digital Meter

Operate by a 9V battery, pulse probe digital meter detects high voltage pulse and measures the energy if the electrical pulse.

The measurement range from 1KVolt to 10KVolt.

High voltage pulse electronic circuit board

The main probe that is mounted onto the PCB board will be used for touching the line with the high electrical pulse. The wired probe is extended and will be inserted into the ground earth for reference.

The device also displays the battery lifespan and blinks when the battery level is too low.

There is no on/off button. The device will be automatically switched on when a battery is inserted or when a high voltage pulse is detected on the probe. When the detected voltage is >10KVolt, the meter will display “HI” to indicate that the detected voltage has exceeded the measurement range. (high voltage sensor)

Contact PIC-CONTROL to custom design and develop a high voltage pulse measurement electroic sensing device.

Touch Buttons User Interface Panel

Control box electronic with on/off switch and touch buttons

Custom Touch Button User Interface Panel

The custom panel’s user interface buttons is designed with capacitive touch sensors. The touch sensor is embedded directly onto the PCB which enables a user to interact and operates similarly to a physical push button switch.

Touch button user interface panel

Elegant Aesthetics Panel Finishing

The simple and elegant panel buttons can be designed to match the look and feel of your product.

Custom sticker, laminate or silkscreen can be designed to overlay on top of the touch button sensors to suit your theme.

Sticker overlay onto user touch panel button interface

Indicator Status Light

LED light indicators are assembled behind the PCB board so that the panel surface is flat and clear for sticker/laminate overlay.

The user is able to monitor the current status of the system with a quick glance.

Feedback from Tone Sound

Tone feedback is design into the touch button panel to enhance the user interaction experience.

A sound tone is a better form of feedback for a user interacting with your product.

This is unlike a visual indicator where the user has to specifically focus their attention on.

Visual Text LCD Display

An additional display panel can be integrate to display more information. Smart device interactive design.

Control Electronics and Connectors

Inside control box electronic and pluggable connectorsPower supply and interface circuit board inside enclosure casing

Cost Effective Solution

Compare to a physical push button switch, touch button switch is simple and can be cheaper in the implementation.

It has almost no mechanical wear and tear, or limited operating cycles.

Contact PIC-CONTROL for customisation of your touch sensing solution today.

Also, check out our mini-touch sensor circuit module.

interface control circuit boardelectronic control circuit board