This board provides relays outputs switched on or off by the K8055 I/O board. It also reads an external contact, its operating voltage as well as the local temperature of switched equipment.

Schematic

PCB layout

Assembled PCB

Assembly with the Velleman K8055 I/O board

Initial Settings on K8055 I/O board

- Remove jumper SK2 and SK3
- Adjust ATT1 potmeter to read the Add on board supply voltage on AD1

Operational use

- in order to switch a relay temporarely set DA1 output High so the latch on the Add on board enables.
- Between terminals Brandmelder C(ommon) and N(ormally)O(pen) is a optocoupler. Shorting these terminals enables Digital Input I1.
- Inputs I2 through I5 can be used to monitor 4 out of the 8 relays.
- Analogue Input A02 is used for the LM35 temperature sensor.

Bill Of Materials

see Downloads for the BOM