greeting and question

Thread Starter

madbrad

Joined Apr 18, 2013
10
Hi everyone, I'll admit I joined because of a question I have. This post is a long one so sorry about that. I couldn't see a new member introduction section. I couldn't really search for anything in here regarding my question since I'm not sure what words I want to look for I tried the letters on the PC board in question but that yielded nothing.
So my issue is this: I got this timer circuit on ebay:
http://www.ebay.ca/itm/321058161266?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
for an led light(it's a 12V truck clearance light) in the garage for a parking guide. The minivan's bumper hits an upside down radio antenna which closes a switch to turn the light on. It's powered by a 12V power supply that's always on, for my car stereo system I have setup in there. You have to back the minivan off the switch to turn it off. If I go real slow, and just barely move the antenna, I can put it in park and the minivan will roll back within the limit of the play in the park pawl. If that's not enough I can just put it in gear and park again to roll another couple inches back. I can't back off much more though, or I'm into the door. But that's not my electronics question. I got the timer so we can leave the minivan pressing against the upside down antenna and exit the minivan and go into the house and drink coffee or jump on the beds or beat the kids, and let the timer turn the light off after a set time such as one minute. I'm not bothered too much about how much time. It's adjustable. this device claims to do what I need, resetting once the switch opens again. The problem is that it didn't come with any diagram or any paper whatsoever. That means I have no idea what terminal is what. I can see the screw terminals are the NO and NC contacts of the relay, and I have tested just the relay, but there's nothing to indicate what terminal is for powering the device, where the switch(or button) would go, etc. You can see 3 2 prong terminal points. it came with a jumper for one of them in the bag. I believe it's for selecting between two modes, that is, two different time ranges for the timer, but I don't know which one it would go on. I have found similar devices online that look identical except all the terminals are screw types like the ones for the contacts, except for one which is a white plug. None of those ones show any diagrams on their pages either. I have asked the vendor and am awaiting a reply. Does anyone know the terminals of this thing?
 

tracecom

Joined Apr 16, 2010
3,944
If you find the number of the IC, you should be able to google the number + datasheet and then determine which are the power and ground pins. Then, you should be able to trace the power and ground pins back to the power and ground input on the PCB.

Chances are that the time is adjusted by the pot, and that you will route the power to whatever indicator you are using through the relay, using the wiper and the NO contact.
 

Thread Starter

madbrad

Joined Apr 18, 2013
10
The first thing I did when I took it out of the package was google FC-16 and FC-16 with other words like wiring or stuff like that, but that got me nothing useful. It's all I can read on the board. There's also some chinese on it. There are traces on both sides of the board. It's almost impossible to follow the ones on the top side.
 

Pencil

Joined Dec 8, 2009
272
Is this possibly the same board?

It has different connectors, but looks similar.

LINK1

And a discussion about pinout.

LINK2

I'm guessing the I.C. may be a 14 pin microcontroller.
 

Thread Starter

madbrad

Joined Apr 18, 2013
10
Yes Post # 4 of this thread has a link to the picture they sent me with the pinouts(they have since sent another with engrish).
That pic looks like your pic, as far as the terminals go. They believe it is the same for mine. Mine's 12V.
I have tried that and it isn't doing anything except showing power by turning on the red LED. Perhaps it's defective.
 

Pencil

Joined Dec 8, 2009
272
I have tried that and it isn't doing anything except showing power by turning on the red LED. Perhaps it's defective.
Are you triggering it by momentarily connecting the two
pins on your board that are in the same location as the
white connector on the board in the picture?

Does the relay make any noise (clicking)?
 

Thread Starter

madbrad

Joined Apr 18, 2013
10
yes, once the power is applied as per the diagram, the red LED is on, then I short the other pair of pins which in the second pic would be the white plug, and the relay should change state and the green LED should turn on indicating the countdown has begun, but nothing happens. No click or green light. I have applied 12V directly to the coil and it works. Their diagram shows a NC momentary pushbutton there though.
 

Pencil

Joined Dec 8, 2009
272
Did you try adjusting the pot?

Can you get any numbers off of the I.C.? You may have to get the
light at just the right angle to be able to read any markings. I suspect
the markings have been removed, but traces may still remain.
 

Thread Starter

madbrad

Joined Apr 18, 2013
10
Yes I tried both extremes of pot adjustment and held the switch closed for long periods and nothing. But in any case the relay is supposed to click immediately and the green LED is supposed to turn on immediately. Only FC-16 can be read on the board, and some very tiny chinese writing in another spot. there are white lines all over that look like they delineate sections, and on the back some that tell you the parts of the relay. It doesn't look like anything was removed. If you google FC-16 you get pics like yours, but no useful information.
 

Thread Starter

madbrad

Joined Apr 18, 2013
10
It is the exact same board as the one in your link. Same printing and markings etc.
When I have 12V applied at the reputedly correct pair of pins, there's as expected 12V at one of the switch pins. But I will test at the IC pins too. The IC has 14 pins and I assume a 555 but it has no printing on it at all. Well there might be something but it's not white, maybe etched in the plastic, way too small to read. I'm thinking the IC is just bad.
 

Thread Starter

madbrad

Joined Apr 18, 2013
10
It looks upon closer inspection that they might have covered the printing on the IC with black marker. I tried wiping it with acetone but that likely also took off the printing.

IC pin readings with module powered but not triggered:

1: 8.9V
2: 8.3
3: 8.6
4: 0
5: .77
6: 13.1
7: 15
8: .77
9: 15
10: 15
11: 0
12: .77
13: .77
14: .77
 

Pencil

Joined Dec 8, 2009
272
IC has 14 pins and I assume a 555 ....
Maybe not.

See if you can confirm or deny any of this by following traces on board.

Pin 2 to capacitor by pot.

Pin 8 to base of a transistor or MOSFET connected to relay coil.

Pin 14 to supply (Vcc)

Pin 7 to ground.

Pin 6 to trigger.
 

Thread Starter

madbrad

Joined Apr 18, 2013
10
Pin 2 to capacitor by pot. Yes that is the only one easy to see. Plus, continuity test conforms.
Pin 8 to base of a transistor or MOSFET connected to relay coil. continuity test says to the nearest resistor, test at one transistor leg less bright.
Pin 14 to supply (Vcc) continuity test says yes.
Pin 7 to ground. continuity test says yes.
Pin 6 to trigger. continuity test says yes but less bright, maybe just a resistor along the way?.
 

Thread Starter

madbrad

Joined Apr 18, 2013
10
Well thanks, you've exerted a lot of effort for this. From that it looks like the seller was right about the wiring info.
Like I said, I didn't have the seller's wiring info when I started the thread. Once I had it, this was just to see if they were right, and jusy conversation.
I guess it is a bad module. They say they will take care of it. I have to send them a pic of how I wired it on the bench.
 
Top