Suggestion needed ( zero cross dectect )

[1Steveo]

Im trying to modify a motion sensor to run off of battery power.
All the circut is running off of 5 volt except I think the main ic is looking
at the zero crossing from the ac line

Anyone have any suggestion how i can simulate this?
The location is were r11 and r12 conect.

here is a picture of the circuit

**broken link removed**

 

[Sebi]

For motion detectors no need zerocross detection from mains.
I mean, this PCB coming from an outdoor lamp with motion detector.
In this case - i think - this is an additional flip-flop circuit for continous light. (few years ago i've made some reverse-engineering) In my circuit, when the power switch pushed quickly twice, the lamp go to continous mode...

 

[1Steveo]

I guess you are rigtht reading the user manual it does have a manual override by flipping the switch off and on for 1 sec.
Any suggestion? tips on this board ?
The board seems to semi work when r11 and r12 removed and left the ic floating.
I did try to inject a 60 hz at R11/R12 with a 555, but no luck

 

[Nigel Goodwin]

I guess you are rigtht reading the user manual it does have a manual override by flipping the switch off and on for 1 sec.
Any suggestion? tips on this board ?
The board seems to semi work when r11 and r12 removed and left the ic floating.
I did try to inject a 60 hz at R11/R12 with a 555, but no luck

The only reason I can see for having a zero crossing signal is if the circuit uses a triac to switch a mains lamp on - to make sure you switch at zero crossing to reduce interference. As you're using DC you can't use a triac anyway, so it won't matter. Depending how it's designed, you may need to take the zero crossing line either high or low, you could really do with drawing the circuit out and posting that.

 

[Sebi]

If possible, put a photo about component side, i try some rev.eng. on this weekend...

 

[1Steveo]

Sure I be happy too!!
Ignore the wires in place of the relay ( I added a buzzer for testing ).

**broken link removed**
**broken link removed**

Thanks for looking

 

[Sebi]

My first impressions: C12, R20, Q4, ZD3, C13 is a regulator circuit with U_zd3-0.7V output voltage, probably about 12V. So: first connect the DC voltage direct to C12, min 14V,maximum as capacitor data shown.

 

[gerty]

Are you covering the photocell, for testing purposes??

 

[Sebi]

Here is the circuit of transformerless power supply section. As gerty suggested, the CDS LDR must be covered, because it blocked the PIR sensor.

 

[1Steveo]

Nice drawing

I have the battery (9v) connected just like you said. Sensor is covered with a pencil eraser.
I do have 5 volts across C13.
The board will not operate until i disconect R12 , R11 and let the trace to the ic "float".



steveo

 

[Sebi]

O.K. You can try one more thing: put a 10k resistor to R12 position, and to this IC point a pushbutton to GND.Now the pushbutton work as the manual said. Some functions depend from slide switch.Maybe after power on the internal flip-flop always going to blocked state.

 

[1Steveo]

Well tried the 10 k resistor, and push button switch ( tapping jumper to gnd), but still no luck.

note i'm leaving the slide switch in "test mode" as i assume this ignores the ldr and lest you adjust the sensor during daylight.

I'm still woundering why R11 (1meg) is there, going to the AC line.

Steveo

 

[Sebi]

This resistor feed the pulse from mains switch to flip-flop. Are You sure the circuit was good before experiments?
Unfortunately hard to rev.eng. this surface mounted IC.

 

[1Steveo]

Yes If I put every thing back the way is was. The sensor will work
I done it many times.

Thanks for trying to help!

Steveo