read Chinese data sheet ? time delay relay FC-31

I have been trying to figure out how to operate this relay
model FC-31

http://www.aliexpress.com/item/-/962902764.html
item 962902764

also available on amazon and the like.
finally found the data sheet and figured out how to control it.

two pins that are un-marked are the control points. close the circuit and the relay energizes. open the circuit and the timing starts. a note is that there is no de-bounce. the unit requires a good signal before entering the timing.

board voltage is the same as the marked relay voltage. I have seen both 5 and 12v

hope this helps someone

FC-31 relay.bmp (554 KB)

The one drawback of buying from China is that the sellers never give enough information about the product. They may give the voltage but not the current, or where you need to know the size, that's omitted from the description. And there seems no easy way to ask a question about the product. Bloody annoying! :stuck_out_tongue_closed_eyes:

the photo of the part shows the relay. the relay is marked so you can find the coil voltage and contact ratings. the only way to find the power consumption of the control circuit is to put in on a bench and test.

what, for a few dollars you think you would not have to work for it ?

I needed the schematic too so I reversed engineered it. Here it is a little late for you perhaps but hopefully it will help others. i don’t know why they don’t publish the schematic and actually go to the trouble of sanding off the numbers on the 4541 IC. No one is going to copy the board as you can’t even buy the parts for what they sell the completed boards for with shipping!

SCH_Relay Board.pdf (21.6 KB)

I was hoping that someone had played with this more and had something more than the schematic, like the datasheet. I am trying to see if I can take a normally closed signal (alarm out), and apply it to a normally open circuit, to make a light turn on, with this board. I am using a Roiscok RK210PR PIR Sensor which has a normally closed 12vdc 100ma alarm circuit. I wanted to use this HC-31 relay with the Roiscok but now I am thinking I need to abandon one or both of them. Anyone have any ideas?

http://roiscoks.en.hisupplier.com/product-134449-PIR-Motion-Detector.html

better off to start a new thread.

Amplex,

You could still use this circuit. You should be able to connect your NC alarm relay in series with 12v power and VCC on the 2 conductor terminal. Then connect your light and power source in series with the NC and Common contact on the 3 conductor terminal. I dont think it matters if you use S6 or S7 if you dont need the delay function.

This results in the board having power when your NC alarm relay is in normal mode. The relay board loses power when your alarm is triggered. The output relay has been open, and now shuts causing the light to turn on. Things get slightly more tricky if you want the delay functions.

It's hard to trace through that board. However that schematic for the FC-31 is incomplete with some obvious errors. Q output of the CD4541 shows connected to Vcc (shorting the output). The way Q2 transistor is connected to the collector of transistor Q3 is incomplete, as there is no path to bias Q2 ON ( it will always stay OFF). The base is always floating (not great either)

Rontierra, as you said "It's hard to trace through that board"

I spent hours reverse engineering the board and decided to post it to be nice. Out of all that work I only see one omission, The 10K pullup resistor for Q3 is missing. Any one with a brain could easily see what that part of the circuit is doing even with the resistor missing. I wasn't designing the board I was reverse engineering it to get an idea of it's capabilities as it obviously had more than the manufacturers "datasheet" suggests.

In the two problems you state you made an OBVIOUS ERROR (to use your words) on one. You stated "Q output of the CD4541 shows connected to Vcc (shorting the output)". Q/nQ select (pin 9) is an INPUT to select the default state of the output (Q) on pin 8. Connecting it to VCC makes Q high after reset.

So after 1300+ downloads not one person has said thanks. All I see are whiners who want everything handed to them so they don't have to think or learn and now an inconsiderate person who overstates a problem on the board and makes a real obvious error not even getting his criticism right.

I wish I could pull the schematic I posted off. I have a newer version of the schematic with the pullup resistor added and also directions on how all the inputs and outputs work. I don't think I will be posting it any time soon.

tpknet: I needed the schematic too so I reversed engineered it. Here it is a little late for you perhaps but hopefully it will help others. i don't know why they don't publish the schematic and actually go to the trouble of sanding off the numbers on the 4541 IC. No one is going to copy the board as you can't even buy the parts for what they sell the completed boards for with shipping!

Thanks, tpknet. The board I bought has only small adjustment available. I think the wrong pot was used. Your schematic should help me fix it (I only want a 15 min time so may just use a fixed res.)

Thanks Caspa-B,

I really appreciate you taking the time to say thanks. I was so frustrated at Rontierras post that I would have retracted the schematic if i could have figured out how to do it.

Now I am glad I didn’t because I posted it to help out people like you. Almost 2000 downloads. There must have been a few other good people in there too I guess.

Thanks again,
Todd