6 Channel Relay Driver Card

Features

• Drives Ultimate relay-switched LPF kit
  • Open collector to turn off relay
  • Drives low to turn on relay
  • Only turn on one output at a time
• Inputs
  • 6 channels (5 used)
  • Active-high in to drive relay to on state
  • 3.3K to transistor base
    • 1 mA for 3.3V drive
    • 1.5 mA for 5V drive
• Outputs
  • Open Collector outputs from 2N3904 NPN transistors
• Power
  • 9-14V power in
  • 5V power out to power relays
  • DC jack
• 36x37mm card
  • 3 PCBs for $11 from OshPark

Ultimate Relay Card

• Ultimate relay-switched LPF kit
  • Ultimate relay-switched LPF kit Build Instructions
• Takes five QRP Labs Bandpass Filters

Ultimate Relay Card Connections

• RF output from the connections circled in yellow
  • An alternative is to cut the track from the SMA connector center pins and add a wire to connect it to the common bus track that runs horizontally across the board, finishing at the "RF" pad circled in yellow
• The RF input is the RFI pin of the 2 x 5-pin header on the left of the board (same as in the Low Pass Filter kit usage)

• Jumpers

Ultimate Relay Card Jumpers

Connectors

J1 - Input Connector

1. N/C
2. IN1
3. IN2
4. IN3
5. IN4
6. IN5
7. IN6
8. GND

J2 - Output Connector

1. GND
2. OUT6
3. OUT5
4. OUT4
5. OUT3
6. OUT2
7. OUT1
8. 5V OUT

Power Connector

• 7-14V input
• Center positive

Control via VFO-003

• VFO-003
  • Band select via menu option
• J8 - Arduino P5-P9
• Arduino pins

1. Arduino D5 - 10M select
2. Arduino D6 - 15M select
3. Arduino D7 - 20M select
4. Arduino D8 - 40M select
5. Arduino D9 - 80M select
6. Vcc
7. GND
8. GND

Testing

• Apply 9-12V to DC jack
• Use LED w/ resistor on output to check 5V
• One channel at a time
  • Pull up channel input to +5V
  • Check output with LED pulled up to +5V out

CAD