DIY Electronics Kit 108 Serial Isolated Input/Output Module

The DIY Electronics Kit 108 is a serial-controlled input/output module for industrial control and sensing applications. It combines 8 Form C relay outputs with 4 optically isolated inputs in a compact plastic enclosure. The module accepts commands via standard serial port (D9 connector) from an external controller—such as a PC or PLC—and maintains relay states independently after disconnection. Relay contacts handle up to 15A at 120VAC or 10A at 240VAC for resistive loads, with 5A ratings for inductive circuits. The four opto-isolated inputs operate from 5VDC to 24VDC and provide 2500V peak galvanic isolation. All I/O connections use pluggable screw terminal blocks for straightforward field wiring. Serial communication supports cable runs up to 100ft, enabling remote operation in distributed control architectures. The unit requires a 9-12V DC power supply rated for 500mA minimum and measures 140(W) × 110(D) × 35(H)mm.

## Technical Specifications

• **Relay Outputs:** 8× Form C SPDT contacts
• **Relay Contact Ratings (Resistive):** 15A @ 24VDC; 15A @ 120VAC; 10A @ 240VAC
• **Relay Contact Ratings (Inductive):** 5A @ 24VDC; 5A @ 120VAC; 5A @ 240VAC
• **Maximum Voltage:** 240V AC / 110V DC
• **Maximum Current:** 15A per contact
• **Maximum Power:** 1800VA / 250W
• **Minimum Load:** 5VDC, 10mA
• **Relay Life (Mechanical):** 10,000,000 operations
• **Relay Life (Electrical):** 100,000 operations
• **Operating Time:** 10msec maximum
• **Isolated Inputs:** 4 channels, opto-isolated, polarized
• **Input Voltage Range:** 5-24VDC
• **Isolation Voltage:** 2500V peak / 1775V RMS (1 second)
• **Power Supply:** 9-12V DC, 500mA minimum
• **Physical:** 140(W) × 110(D) × 35(H)mm, plastic case

## Key Features

• Form C relay contacts for high-side or low-side switching
• 2500V galvanic isolation on input channels
• Pluggable screw terminals for inputs and outputs
• D9 serial interface with extended cable support (up to 100ft)
• State retention independent of controller connection
• Double-sided through-hole PCB construction

## Typical Applications

• Industrial equipment control and switching
• Remote monitoring and load management
• Sensor input acquisition with high voltage isolation
• Contact closure and external voltage sensing
• Distributed automation systems requiring serial interface

## Compatibility & Integration

The module integrates with any external controller capable of serial communication at standard baud rates. It operates as a passive I/O device—no firmware reprogramming is required. The D9 connector and screw terminal blocks ensure compatibility with standard industrial cabling and field devices.