RDL ST-ACR1M Microphone-Level Controlled Relay User Manual
Model: ST-ACR1M
Introduction
The RDL ST-ACR1M is an Audio Controlled Relay designed for reliable operation in various audio control applications. This device is part of the STICK-ON® series, engineered for convenient installation. It is specifically designed to switch based on low-level audio sources, such as microphone signals.
The unit features two multiturn trimmers for precise adjustment: a SENS potentiometer for audio input sensitivity and a DELAY control for setting the relay release time. A threshold LED assists in accurate sensitivity adjustment.
Product Overview
Figure 1: Front view of the RDL ST-ACR1M unit, showing input terminals, power terminals, sensitivity and delay adjustment points, and relay output contacts.
The ST-ACR1M unit features clearly labeled terminals for microphone input, power, and relay contacts. Adjustment potentiometers for SENS (Sensitivity) and DELAY are located on the side of the unit, as indicated in the diagram.
Setup and Installation
- Power Connection: Connect the appropriate power supply to the PWR terminals. Ensure correct polarity.
- Microphone Input: Connect your microphone or mic-level audio source to the MIC INPUT terminals. Observe proper polarity for balanced or unbalanced connections. The unit is designed to sense signals between -65 dBu and -20 dBu.
- Relay Output: Connect the DPDT switching contacts to the circuit you intend to control. The relay contacts are shown de-energized in the product diagram.
- SLAVE Output: If required, connect the Open-Collector SLAVE Output to external control systems.
- Mounting: The ST-ACR1M is a surface-mount device. Secure it in a suitable location using appropriate fasteners (not included).
Operating Instructions
- Adjusting Sensitivity (SENS):
Use a small screwdriver to adjust the SENS potentiometer. Turn clockwise to increase sensitivity (trigger on lower audio levels) and counter-clockwise to decrease sensitivity. The threshold LED will illuminate when the audio signal exceeds the set threshold, indicating the relay will activate.
- Setting Release Delay (DELAY):
Adjust the DELAY control potentiometer to set the time the relay remains activated after the audio signal drops below the threshold. The adjustment range is from 0.5 seconds to 5 seconds. Turn clockwise for a longer delay and counter-clockwise for a shorter delay.
- Relay Operation:
When the audio input signal exceeds the sensitivity threshold, the internal relay will energize, changing the state of its DPDT contacts. When the audio signal falls below the threshold, the relay will de-energize after the set DELAY period.
- SLAVE Output Function:
The Open-Collector SLAVE Output provides a signal that can be used to control other compatible devices in conjunction with the relay's state.
Maintenance
The RDL ST-ACR1M is designed for long-term, reliable operation with minimal maintenance. Periodically inspect all connections to ensure they are secure. Keep the unit free from dust and moisture. Do not attempt to open the casing, as there are no user-serviceable parts inside.
Troubleshooting
- Relay Not Activating:
- Check power supply connection and ensure it is within specifications.
- Verify audio input signal is present and at a sufficient level.
- Adjust the SENS potentiometer clockwise to increase sensitivity. Observe the threshold LED.
- Ensure microphone input connections are correct.
- Relay Always Active or Not Releasing:
- Check for continuous audio signal presence at the input.
- Adjust the SENS potentiometer counter-clockwise to decrease sensitivity if the ambient noise is triggering the relay.
- Verify the DELAY setting. If set to maximum, it will take longer to release.
- Incorrect Delay Time:
- Adjust the DELAY potentiometer to achieve the desired release time between 0.5 and 5 seconds.
Specifications
| Feature | Detail |
|---|---|
| Model Number | ST-ACR1M |
| Manufacturer | RDL |
| Audio Input Sensitivity Range | -65 dBu to -20 dBu (adjustable) |
| Relay Release Delay Range | 0.5 seconds to 5 seconds (adjustable) |
| Contact Type | DPDT (Double Pole Double Throw) |
| Contact Material | Silver |
| Current Rating | 2 Amps |
| Connector Type | Plug-In |
| Mounting Type | Surface Mount |
| Package Dimensions | 5.04 x 2.05 x 2.01 inches |
| Weight | 2.82 ounces |
Warranty Information
This product is covered by the manufacturer's standard warranty. For detailed warranty terms and conditions, please refer to the official RDL website or contact their customer service directly. Keep your proof of purchase for warranty claims.
Support and Contact
For technical assistance, troubleshooting beyond this manual, or product inquiries, please contact RDL customer support. Visit the official RDL website for contact information and additional resources.
Manufacturer: RDL
Website: www.rdlnet.com
