@Samuel235 said in Homini AC Powered Relay (2) Module:
OMRON G3MB-202P
Okay I'm trying to help you with the fuse component.
I found a datasheet for the OMRON G3MB-202P. And there are enoght information to be known for fuse selection.
I try to calculate it here (and i will try it with my bad English ).
The most important information is the melting integral.
The Melting integral has A²s as unit. So this means the maximum current for a time can exists without damaging the device. For further information look at wikipedia.
So we need any further information about:
the protection which is present before (the typical circuit protection in private houses)
the melting integral from the device which we want to protect
the maximum voltage
the maximum switching current
the breaking capacity
Inrush current for the switched devices (we can't know)
Typical values for an automatic circuit breaker in private houses are:
from 25 to 100 A²s
230 V AC
16 A
So this protection isn't good enough for our relay. The relay have these values:
230 V AC
2 A maximum switching current
I²t value (melting integral): 4 A²s
the allowed inrush current over a small time is higher than the melting integral. It is a bit confusing i think, but if we calculate the protection for the given melting integral and it's fine. So we can define the parameters for the client (switching site of this application here)
The fuse have to be:
I²s value higher or equal than the I²s value from the existing protection
rating voltage over 230 V AC
rating current 2 A or lower (because 2 A is the maximum at 25 °C, for 40 °C it is about 1.6 A)
a maximum switching time of 1 second at 2 A or lower time with higher current but below 4A²s! To calculate use the switching time from the fuse datasheet an multiply it two times with the given current for this switching time.
And i think a fast blow fuse would be the best. There are SMD fuses with 10.1 x 3 mm and 250 V AC available.
If there is no fuse available with the values above, we could combine multiple fuses. A possible solution could be one bigger fuse for both relays and the ac/dc component. And a smaller fuse for the switching site of the relay and the HLK-PM01. But for this it is important that the circuit have only one input for the hot one (L) of 230 V and one output for each relay. In this case we could reduce the big connectors from 6 to 4. Like (L, N, Relay1, Relay2).
And the temperature fuse can work for all components too
So the protection for the primary site of the HLK-PM01 is a problem i think. Because the are no information available about the I²s value from HLK-PM01.
I hope you can understand my English and could follow my explanation?
Hello @reinhold,
yes the PCB works, I have assembled one and tested it for basic function (not all buttons and leds) but I have stability problem that comes from the software, I put it aside to do other things and didn't have time to go back to it, if there is some interest for it I will find some time and finish at least a basic script.
I like those relays. Is that 3 different switched outputs? One thing I always liked about european wall switches is that they give you more room for components. I would like to use a similar type of relay for my in-wall switches, but with the way US single gang wall boxes are, there is a pretty narrow space constraint. I might be able to fit it if I did away with the thermal fuse, but I don't want to give up tat bit of added safety just for that.
The choice of MOSFET can be tricky. Seems that irlz44n was discontinued so you may need to find one adapted to the voltage and current you want to handle.
In all the cases you need to get a logic MOSFET too, meaning that they are fully open usually around 1 to 3V.
Also I'm sort of confused as it seems to me that L7812CV is a Voltage regulator, not a MOSFET. So if you are actually using that in the MOSFET spot it will definitively not work.
Especially if you are handling high current or voltage I would recommend using one from a reputable source for your MOSFET, I recently switched from mouser / digikey / aliexpress to mostly use http://www.arrow.com as you get free regular shipping, event if you order a couple of components (no affiliation to them whatsoever).
@shabba
Hi, unfortunately I don't have time and patience for doing BOM's on all of my projects but in this case it's not very hard as the external component count is greatly reduced by using the NRF51822 RF SOC which is a PTR5518 module from Aliexpress. Other than that there is the Microchip touch sense controller - MTCH105 and the usual smd resistors(0603) and caps. Other than that you're not forced to use and solder the onboard dc-dc converter so you don't have to worry about those components - you just need to solder the 3V_EN jumper to use the Livolo 3V output coming from the main relays/power supply board.
