NOYITO PC817 4-Channel Optocoupler Isolation Board Voltage Converter Adapter Module 3.6-30V Driver Photoelectric Isolated Module

I needed to interface a 12V alarm system into a component of my own design (5V). I wanted isolation and voltage conversion. This board worked fine.Some of the other reviews mentioned that grounds are connected together. This is true, and caused issues with interaction in my design. Wished that I could separate the Grounds. To solve this issue, I ordered the two channel version of the same optocoupler. In fact, I ordered a selection of the product with a selection of channels for future projects. I did find that if you use a number of these boards for I/O it can become quite a mess of wires. Nevertheless, they do a good job and I have found that they work through a wide voltage range.Great product. Recommended.

It was perfect for my application

Works fine but connectors are very finicky..the instructions could be clearer on configuration..also there is a 3 k resistor in series with the output v terminal so the actual isolated output v is going to depend on the load resistance. I used this as an emitter follower by removing the ground jumper... still not exactly clear on possible configuration and pull up pull down resistors. But works fine...leds built in is nice...

Does not work for my application as the Input grounds are tied together.I also found that Input and output grounds were tied together, but could be isolated by removing the jumper.My expectation was four totally independent couplers.The product details are incorrect. I see other similar reviews going back to 2019.Why hasn't the product information been updated ?You get what you pay for.

It has a small footprint, converted my 12v input signal to 5v, which is what I needed. I have a ESS smoothstepper Ethernet board for my homemade cnc machine. I ended up using 3 input pins on port #3 of my smoothstepper for 3 proximity limit swtches. My limit switches have 12v signals and my smoothstepper can only take 5.5v max input.On the input pins of the Optocoupler I connected ground and the 12v signals from my limit switches. On the output pins of the optocoupler I connected 5v to the voltage pins, and the ground pin to the smoother stepper input pins. I removed the ground jumpers on the optocoupler board. The smooth stepper has a pull down resistor on each input pin on ports #3, I think it's 47k ohms.I had issues at first because the smoothstepper port #1 has input pins too, but those input pins have 4.7k ohm pull up resistors, rather then pull down resistors. Switching to port #3 with pull down resistors fixed the issue.

If you have a project which requires voltage level conversion or voltage isolation to reduce noise, then this board is what you need. For example, I completed a project with 12V logic inputs and outputs over a long noisy wiring run. Those 12V lines are translated though this octocoupler to switch 3V3 lines on a very sensitive microcontroler. Note: pull-up or pull-down resistors are required since this octocoupler is floating. However, the end result is a 100% reliable voltage level conversion, even when deployed in some very harsh conditions.The only limitation of this octocoupler is that the switching is too slow to translate a serial type bus, I2C, or SPI. It is really only appropriate for digital logic. Also, each channel on the octocouplter can operate at independent voltage levels, meaning that all 4 channels do not have to share the same reference voltage, such as with a transistor based logic level converter.I am extremely happy with the quality, design, and performance of this module and will make it a go to going forward.

I don’t know why they have separate grounds on the input side, it must be for looks. They’re all tied together on the board. If you’re switching the ground side on the inputs this board won’t work. All four channels will be triggered at the same time. Stupid. They have them separated on the output but not the input..

Works just fine. Use it to stepdown 24Volt End Limit Signals for my CNC. Down to 3.3v for the Smooth-steeper CNC Controller. Easy to mount using standoffs, and it just works. Leds are really nice to see which ports are active.