High Power Logic Controlled Relay-8 A

The RDL ST-LCR1H is a high-power, logic-controlled relay designed for switching speaker lines from switches, logic circuits, or compatible open-collector outputs. Its double-pole, double-throw contacts support up to 8 A at 250 Vac or 30 Vdc, while the amplified-audio power rating reaches 500 W. Multiple control inputs and a SLAVE open-collector output provide practical options for integrating the relay into new or existing control systems.

Ideal Use Cases

The ST-LCR1H is intended for applications that require remotely controlled switching of speaker lines. A push-button or maintained switch can activate the relay through the SLAVE terminal, while equipment with a suitable open-collector output can provide logic-based control. RDL switching STICK-ONs® with open-collector outputs are specifically identified as suitable control sources. Separate voltage inputs also allow the relay to respond to control signals from equipment providing 3.5 to 12 Vdc or 12 to 35 Vdc.

Why Choose This Model

This model combines high-current switching contacts with three clearly defined control methods. The SLAVE input supports activation by connecting the terminal to ground, the 5V+ input accepts 3.5 to 12 Vdc, and the 24V+ input accepts 12 to 35 Vdc. With either voltage input, the relay remains on only while the applicable control signal is present. This flexibility allows one relay model to interface with switches, open-collector logic, and two broad ranges of DC control voltage.

Installation and Integration

The ST-LCR1H requires a ground-referenced 24 Vdc supply at 50 mA. Recommended power supplies, which are not included, are the PS-24AS for the USA and the PS-24AX for international use. For manual control, connect the SLAVE input to ground through a remote push-button or switch; the relay turns on when that switch is on. The same input can be driven by another device’s open-collector output. For voltage-controlled operation, apply a compatible signal to either the 5V+ or 24V+ input according to the available control range.

The SLAVE terminal also provides an open-collector control output rated at 25 mA. It is suitable for driving indicators or additional slave LCRs. The unit measures 0.7 inches high by 3 inches wide by 1.6 inches deep, equivalent to 1.7 by 7.6 by 3.9 centimeters. Its specified ambient operating range is 0° C to 55° C.

Performance Highlights

The relay uses double-pole, double-throw switching contacts. Maximum current is specified at 8 A at 250 Vac or 30 Vdc, and maximum amplified-audio signal power is 500 W. These ratings make the model appropriate for the speaker-line switching role identified by RDL while providing defined limits for AC and DC contact loads. The 24 Vdc, 50 mA power requirement also gives system designers a concrete basis for selecting and allocating control-system power.

What Makes It Different

The ST-LCR1H is distinguished by the combination of its 8 A relay contacts and its range of control interfaces. A system can use a grounded remote switch, an open-collector control output, a 3.5-to-12 Vdc signal, or a 12-to-35 Vdc signal. The available 25 mA open-collector SLAVE output extends integration possibilities by supporting an indicator or slave LCR. This input-and-output arrangement addresses both direct operator control and logic-controlled switching without changing the relay model.

Final Assessment

For systems requiring DPDT speaker-line switching with clearly specified electrical limits, the RDL ST-LCR1H provides a focused set of control and relay functions. Its 8 A contacts, 500 W amplified-audio rating, three activation paths, and open-collector output make it a versatile control component. Installation planning should account for the required external 24 Vdc supply, the selected control method, and the stated contact ratings and operating-temperature range.