Description
The ST-ACR1M is a compact microphone-level audio-controlled relay module designed to switch low-level sources based on detected audio. It monitors mic-level signals and activates a DPDT relay when the input exceeds a user-adjustable threshold. The unit is intended for reliable silence sensing and simple control tasks in AV installations.
The module provides two multiturn trimmers for precise setup: SENS to set input sensitivity and DELAY to set relay release timing. An audio threshold LED aids accurate sensitivity adjustment. The input sensitivity range is adjustable between -60 dBu and -20 dBu, enabling use with a wide range of microphone sources.
Performance highlights include a 25 ms activation response time and a nominal 250 ms re-trigger delay. The relay offers double-pole-double-throw contacts rated for up to 60 W and switching ratings of 220 Vdc, 125 Vac, 2 A. The release delay is adjustable from 0.5 seconds to 5.0 seconds to prevent chatter on intermittent signals.
Connectivity is flexible: the audio input presents a 10 kO balanced bridging impedance and may be connected balanced or unbalanced. A ground-referenced 24 Vdc power input at 50 mA powers the module while an open-collector SLAVE output provides up to 25 mA drive for indicators or downstream relays. An LED indicator provides visual feedback for threshold setting.
Typical applications include microphone-triggered room control, talkback activation, and automated source switching in broadcast and installed sound systems. The ST-ACR1M is well suited to environments that require silence sensing or audio-triggered control where line-level detection is not appropriate. It integrates cleanly into rack-mounted or distributed control systems as a compact stick-on module.
Installation is straightforward and requires simple wiring for audio, power, and relay connections. The small footprint and lightweight construction allow flexible mounting in confined spaces. The module operates from 0° C to 55° C and is built for dependable continuous operation in professional AV environments.
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Our main goal is to ensure your complete satisfaction with our service and products. If, for any reason, you are not 100% satisfied with your purchase, you can return it within 30 days of the purchase date for a full refund. Our 30-day money back guarantee applies to all of the products we sell, except for: TVs and monitors 20" and larger, Special Order merchandise, or any item indicated as non-returnable. Shipping is not refundable. Prior to returning your purchase, a Return Merchandise Authorization (RMA) number will be provided to you.
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Exchanges:
If the item was sent back to us for an exchange, please allow 3 - 5 business days for the replacement to be processed.
No Returns/Exchanges on the following:
- TVs and monitors 20" and larger
- Special Order merchandise
- Any item indicated on the website as non-returnable
For more information see our official Return Policy
