“BIG 3″ of ODOT Relay Output Modules

Digital output mainly comes in two forms: transistor output and relay output. The relay form of output modules, with the reliability and high load capacity brought by the mechanical contacts’ structure, is irreplaceable by transistors. Currently, there are still many industry scenarios that require this type of output.

However, due to differences in features and usage, customers may find it challenging to choose. Today, let’s explore the differences between several relay output modules offered by ODOT Automation.

1.  CT-2738

8-Channel Relay Output Module：1A/30VDC/30W

8-Channel Normally Open Relay Output Module with 8 LED channel indicator lights. It features low on-state resistance (≤100mΩ), isolation between channels, built-in bidirectional TVS diodes, an internal RC circuit, and can handle resistive and inductive loads.

This module is designed for a 24VDC voltage level. When dealing with inductive loads, which may cause sticking due to the influence of reverse electromotive force on the relay contacts in the presence of DC power, the module’s circuit board includes freewheeling diodes to release the energy from inductive loads. Thus, the CT-2738 can handle both resistive and inductive loads reliably. It’s important to note that this module has a maximum load capacity of 1A for a single contact and cannot be connected to alternating current (AC).

2.  CT-2754

4-Channel Relay Output Module：3A/30VDC/90W

4-Channel Normally Open Relay Output Module with 4 LED channel indicator lights. It features low on-state resistance (≤100mΩ), isolation between channels, built-in unidirectional freewheeling diodes, and an internal RC circuit. This module shares similar functionalities with the CT-2738 model, designed for use with a 24VDC voltage specification. Like the CT-2738, it cannot be connected to alternating current (AC). However, in addressing the CT-2738′s moderate load capacity, this module reduces the number of channels to four and selects higher-rated relay contacts, achieving a load capacity of 3A, suitable for the majority of DC24V driving requirements.

3.  CT-2794

4-Channel Relay Output Module：2A/250VAC/500VA

4-Channel Normally Open Relay Output Module with 4 LED channel indicator lights. It features low on-state resistance (≤100mΩ), isolation between channels, and can handle both resistive and inductive loads.

This module utilizes stronger contacts, allowing it to support a higher voltage level of AC250V. The contact load capacity is maintained at 2A, and with a voltage of 250V, the single-channel power can reach 250W, providing enhanced driving capability.

Whether it’s DC or AC, resistive or inductive loads, ODOT Automation’s relay output module series can meet your requirements.

Through today’s product introduction, we believe everyone will have a clearer understanding when choosing products in the future. We will continue to bring more industrial-related knowledge, so please stay tuned to the ODOT Blog!