How does a RPI VCC work with a VCC?
Rpi Vcc sources current through 1k to the LED which inputs optical signal to the opto transistor on the other side. No electrical current ground is used for reference. A case with Rpi powered by a battery, the Rpi’s ground can be “floating” and not connected electrically to the relay module.
Can a relay module be connected to a RPI?
A case with Rpi powered by a battery, the Rpi’s ground can be “floating” and not connected electrically to the relay module. The OP’s 4 channel relay module is “Low Logical Level Triggerable” (Low Trigger) with the “JD-Vcc jumper” to suit different configurations of relay power and control signal levels.
Where are the resistors on a Raspberry Pi relay switch?
If you set 5V instead of 3.3V to VCC, you should definitely put one resistor each (~ 1kΩ) between the GPIOs and the IN pins. On the other side are at each relay 3 connections (see picture below): Depending on whether the IN pin is a LOW (0V) or HIGH (3.3V or 5V) is applied either the switch between the centre and right, or Open centre and left.
Do you put resistor between relay and GPIO?
It is recommended to set a small resistor between the Pi and the relay, but it is not absolutely necessary with 3V3. If you set 5V instead of 3.3V to VCC, you should definitely put one resistor each (~ 1kΩ) between the GPIOs and the IN pins.
How to properly use a relay module with JD-VCC?
The schematic of the H/L select jumper relay is shown below. This relay lets the user select the relay as High level or Low level trigger. This schematic is a test of your thorough understanding of the different kinds of relays. Note – You need to study the spec of the EL354 bidirectional input optocoupler shown in Part C above. / to continue,
What’s the difference between VCC and JD on Arduino?
JD-Vcc is the pin to connect to the [external] relay (JD) power supply, while Vcc is the pin to connect to the Arduino or Raspberry Pi power rail/supply
Is the JD-VCC jumper a simple circuit?
The simple wiring and operation described in the short answer above does not involve the JD-Vcc jumper which is a very clever electronic circuit design. The long answer below describes the JD-Vcc circuit in detail, starting from the most basic ideas of High and Low trigger relays with and without optical isolation.