1pcs DC 5V Relay Module 2 Channel Relay with Optocoupler High or Low Level Trigger Expansion Board

Really surprised how easy it was to use these in my project. Seem well built & reliable so far

*Be aware that the relay component on the items doesn't match the spec of the one's on the listing though (blue vs black, for one), but the differences are marginal - just be aware is my advice.**The main thing I'd mention first is that this particular relay has is configurable between high/low trigger, I had to swap the jumper for my first project to 'high' as it was default to a signal low trigger - I assumed the board was working fine because the (helpful) indicator led's were all fired up - so as soon I figured I needed to swap it to signal low trigger it worked swimmingly. I'm using it in my 3d printer to use the onboard 0.3a current-limited JST header (that normally powers the rubbish stock LEDs) as a 5v signal to trigger a higher capacity 5v feed for additional lighting - so I can control it using the stock on/off options. It was quick to get it all working as planned with this relay, and the output seems to work fine with DC instead of AC too.

Like,The small size.Dislike no wiring diagram.I wired this unit with extra low voltage float switches which then triggers the control circuit of my pumps.

works with RNR motion controller for switching on spindle, this 5v relay is way way easier/better than using 24v relay on this card.

Works well. Easy to wire up.

Had no issues. Used with low voltage.

These are nicely designed circuits and well produced boards - they come in a strip but are scored for easy separation, the mounting holes are clear and clean - even the corners are rounded. No overspray of flux and most importantly a decent anti-tracking gap around the relay contacts for added safety. The prescence of the optoisolator is also a welcome feature.The inclusion of terminals for NC & NO plus the high/low trigger jumper allows for total configurability to suit your project or application.The only disappointment is the lack of any kind of paperwork with these boards - they currently command a handsomely high price on Amazon in any configuration/size yet nothing is included in the plain jiffy bag they arrive in and the part number on the board yields nothing if searched for. If you plan to get these you could do far worse in actual quality just make sure to print out the details from the listing as if you put spares into stock or come to repurpose them a year down the line to a new project you'll have unnecessary extra work to do reminding yourself of the particulars.

Excellent little modules which work reliably.I've used loads of these things over the years for all sorts of projects, and these being 5V versions makes them really versatile for USB powered work.Those projects have included both low voltage and mains powered projects (limited to around half their rated power handling) with no issues at all.Good stuff, and on a quality/value-for-money basis.... 5-Stars.