A few short questions about relays

[AndreiArgeanu]

Hi, my 4 channel relay I got of aliexpress just arrived, and I have a few questions.

 Does the rating written on the relay itself stand for the maximum voltage/current it can handle? And is there a minimum voltage/current for the relay?

 And what is the jumper on the top right of the relay for? It says JD-VCC and VCC.

[AdamBGames]

14 minutes ago, AndreiArgeanu said:

Hi, my 4 channel relay I got of aliexpress just arrived, and I have a few questions.

 Does the rating written on the relay itself stand for the maximum voltage/current it can handle? And is there a minimum voltage/current for the relay?

 And what is the jumper on the top right of the relay for? It says JD-VCC and VCC.

Looking at the Datasheet for this relay, the minimum load is 100mA at 5V DC, maximum is 250V in AC/30V in DC, making this a mains voltage capable relay, though the max switching amperage is 15A. https://datasheetspdf.com/pdf-file/948774/FLOURISHING/FL-3FF/1

 

Looking at an image from Handson Technology, it looks like the top right is a serial control bus that requires 5V input through VCC and Ground through, well, GND. JDVCC is the voltage given to the relays, this looks like it can be removed so that external power can be used for the controling of the Relays, this can be useful in some more technical configurations, if you want a cleaner signal going to the relays. Though I imagine for most people this would be fine to just leave.

[mariushm]

Yeah, pay attention to the current each relay needs to stay engaged as well.

Good relays should need around 20-40mA ... those relays... wouldn't surprise me if they need 60-75mA for each relayeach relay needs around 20-40mA of current to stay engaged, so for 4 relays you'll need around 250-300 mA

 

You may have a small 50-100mA power supply for a microcontroller, and want to send the on/off signals using microcontroller pins, but want to power the actual relays from a separate 5v power supply or something less "regulated"

[AndreiArgeanu]

1 hour ago, mariushm said:

Yeah, pay attention to the current each relay needs to stay engaged as well.

Good relays should need around 20-40mA ... those relays... wouldn't surprise me if they need 60-75mA for each relayeach relay needs around 20-40mA of current to stay engaged, so for 4 relays you'll need around 250-300 mA

 

You may have a small 50-100mA power supply for a microcontroller, and want to send the on/off signals using microcontroller pins, but want to power the actual relays from a separate 5v power supply or something less "regulated"

I plan to use it with my Raspberry Pi 4b, and maybe a Raspberry Pi Pico later. Can the raspberry pi 4 deliver enough power for the relays? I believe it should be enoug, though I do have a breadboard power module that should be able to supply the required power.