Triac Dimmer

[Jbliss]

Here is the Circuit I have built however its not working can some one please help explain what I'm doing wrong 

[Simon]

The resistors feeding the triac gate should come from the power directly and not through the load.

[Jbliss]

all the circuits i have seen show the Resistors after the load ?

[Jbliss]

Just tried it and made no differences 

[SeanB]

Triac connections are wrong.. The triac gate has a reference, in this case pin 1. Using the other way round it likely will either be on always  or off, depending on the capacitor charging.

http://www.nxp.com/documents/data_sheet/BT136_SERIES.pdf

Note the gate is referenced to MT1, thus you must always apply the trigger with reference to this.

Read this golden rules as well, will help you understand more.

http://www.nxp.com/documents/application_note/AN_GOLDEN_RULES.pdf

[Jbliss]

so it show be connected around the other way so MT2 is connected to the positive   

[MagicSmoker]

There is no "+" terminal on the mains, but judging by the naming of one terminal as "N" it seems you are in the USA, yes?

The RC values are more appropriate for a 230VAC/50Hz dimmer circuit - try reducing the fixed resistor to 3.3k and the capacitor to 100nF (note that it should be a high voltage film type for safety reasons). Other possible problems are: bad or miswired pot (center and right terminals, with knob facing you); 10k resistor not really 10k (too high or open circuit); diac breakover voltage too high (needs to be around 30V); bad triac; shorted capacitor; insufficient or missing or highly inductive load present - this dimmer circuit will not work without a predominantly resistive load (like a... wait for it... incandescent lamp!).

Triac connections are wrong.. The triac gate has a reference, in this case pin 1. Using the other way round it likely will either be on always  or off, depending on the capacitor charging.
...

Incorrect. Triacs can be triggered by any combination of gate polarity with respect to MT1 (T1) or MT2 (T2) polarity. See relevant excerpt from the BT136 datasheet you posted:

[Jbliss]

Not america in australia Mains voltage is 240

[Jbliss]

ok came back to the circuit today still not working any help out.
ty

[alsetalokin4017]

You might want to take a look at this page:

http://www.circuitstoday.com/simple-lamp-dimmer-fan-regulator

[Paul Moir]

A 10k pot and 500k limit resistor seem backwards.  Like the pot should be a much higher value and your current limit much lower.  In your original schematic, it looks like you have a 500k pot, but your symbols are not clear.  500k likely prevents the TRIAC from ever turning on.  10k probably isn't enough adjustment range to notice.

PS - probably helpful:  is your load always off or always on?  What TRIAC?

[SL4P]

Also assuming you have a DIAC in position D1 (DB2)
Anything else will have unexpected consequences.