National Instruments 781421-33 Electromechanical Relay Matrix Module

The National Instruments 781421-33 is an electromechanical relay matrix card that is specifically designed for use in SwitchBlock systems. It is also known as NI 2833B. It features a robust design ideal for high-power applications with a switching voltage of up to 100 V and a maximum switching current of 2.0 A per channel. This matrix module allows the connection of any input to any output either individually or in combinations. It simplifies wiring and enables dynamic signal routing from devices such as oscilloscopes, digital multimeters (DMMs), arbitrary waveform generators and power supplies to multiple test points on a unit under test (UUT).

The 781421-33 module supports a maximum switching power of 60 W or 62.5 VA per channel. This makes it suitable for high performance applications requiring precision switching. Its thermal EMF is less than 10 µV that minimizes thermal interference in sensitive measurements. It has a bandwidth of 10 MHz. This ensures excellent signal integrity while crosstalk and isolation levels provide clear signal separation across channels.

The NI 781421-33 module is constructed with palladium-ruthenium gold-covered relay contacts that ensure long lasting durability. The relay operates with a typical response time of under 5 milliseconds. The expected relay life under mechanical no-load conditions is up to 1 x 10⁸ cycles while the relay's electrical lifespan. This depends on voltage and current and ranges from 1 x 10⁶ cycles to 5 x 10⁵ cycles. This makes it an ideal choice for long term repetitive testing operations.

This electromechanical relay matrix card features a 160-position DIN I/O connector and requires a power input of 20 W at 5 V and 5 W at 3.3 V. It is designed for indoor use with an operational temperature range of 0 °C to 55 °C and storage capacity from -20 °C to 71 °C. The device is compliant with IEC 61010-1, EN 61010-1 and other safety standards for electrical measurement and laboratory use. It also meets the requirements for electromagnetic compatibility (EMC) under standards such as EN 61326-1 and FCC regulations.