Product Description Product Description The improved SR-104 module utilizes advanced patch technology and supports input voltages of 5V or 9-12V. The dual relays are easily managed via serial commands, with each channel independently adjustable for a delay ranging from 1 to 255 seconds. This module is designed for simplicity, as most serial instructions require only 1 byte to execute their functions. Included with the module is a VB upper computer program and its source code, facilitating easier computer remote control. Upon receiving instructions, the module not only executes commands but also provides feedback on the current status of all relays. Moreover, the module can respond to relay status queries, allowing the upper computer program to verify the success of operations, thus enhancing control accuracy. The SR-104A can be expanded with an MO-94C module to modify control to four relays via a serial port. Specifications Power Requirements: DC 4.5V-5V, positive inside and negative outside; Or DC 9-12V. PCB Dimensions: 71mm (L) x 47mm (W). Features Equipped with STC15F104W as the main control chip. Independent delay settings for each channel from 1 to 255 seconds. Easy operation with most serial commands being single-byte. Comes with an onboard 2-way relay. Relay includes an absorption diode circuit. LED indicator for each channel lights up when relay is engaged. Expandable to control four relays using the MO-94C module via serial port. Includes a power indicator lamp. Improved stability due to the filter circuit with capacitance. Supports 5V or 9-12V input voltage. 1.6mm thick PCB made of military-grade FR-4 plate with reserved mounting holes. Package Includes 1x Relay Board Interface Description VCC: Expansion module power supply positive pole GND: Expansion module power supply negative pole P34: CH3 control line, active high P35: CH4 control line, active high Blue Terminal: Connects to user load. Supports 220V AC equipment or equipment with under 30V DC, ensuring the current does not exceed the relay's standard load. Each relay features a normally open contact, a normally closed contact, and a common contact. The common and normally open contacts conduct when the relay is engaged; the common and normally closed contacts conduct when released.
