Feature:
Each relay needs 15-20mA driver current.
Equiped with high-current relay : DC30V 10A AC250V 10A.
Each relay has normally open and normally closed contact.
The 8 channels are optically isolated, safe, reliable, anti-interference.
Can be selected by jumper relay and TTL or ground.
With power indicator,each channel has a status indicator.
relay coil is with diode protection
Size: 140mm X 55mm
 
 
The driver circuit for this relay module is slightly different compared to traditional relay driving circuits since there is an optional additional layer of isolation. When the jumper is shorted, the relay and the input share the same VCC, and when it is open, a separate power supply must be provided to the JD-VCC jumper to power the relay coil and optocoupler output.
 
The inputs for this module are active low, meaning that the relay is activated when the signal on the input header is low. This is because the indicator LED and the input of the optocoupler are connected in series to the VCC pin on one end, so the other end must be connected to the ground to enable the current flow. The optocouplers used here are the PCF817, which is a common optocoupler and can also be found in through-hole packaging.