light dimmer

[sammy004]

Can anyone help me out on building a real simple 120volt light dimmer

 

[stevez]

Lots of schematics and designs available on the web but some things you need to consider -

What kind of light? Incandescant, fluorescent, HID are some kinds. Some can be dimmed, some can't - for those that can the dimmers are significantly different.

How much power/current?

Continuously variable? What kind of turndown (how low do you want to go) is desired.

 

[sammy004]

its just a regular bulb light for the livinging room 120 volts AC.

 

[MARINE1142]

Why couldn't you just buy a dimmer from homedepot and replace the on off swithc with that?

 

[sammy004]

then where the fun and hobby in designing one. besides the one at Home depot is like $20.00 I want to experiment get my drift.

 

[MARINE1142]

Got it. I know what you mean too. There aint no fun in buying something when you can make one and say ohh that yea I made that.

 

[Misterbenn]

look up Phase angel control.
its a way of controling the brightness of the light by changing how muchof the AC cycle its on for. (like flashing it very quickly)

you'll need to use a TRIAC, there fairly simple, but the posibilitys are endless.

i did one of these for my AS electronics cwk
be carful though, i ended up setting fire to the lab with a stupid mistake
i've learnt to dread the sound of electric sparks, and the smell of burning wires lol

 

[sammy004]

Got it. I know what you mean too. There aint no fun in buying something when you can make one and say ohh that yea I made that.

Exactlly, now you got :lol:

 

[David Bridgen]

Can anyone help me out on building a real simple 120volt light dimmer

This can be used to control the brightness of a bulb or the speed of a small motor.

 

[sammy004]

I also found this on the net https://www.aaroncake.net/circuits/dimmer.htm
but do I have to use a neon lamp for L2 or can I just leave it or use something else also that is a 40502 triac what exactly is the rating of that piece.

 

[Nigel Goodwin]

I also found this on the net https://www.aaroncake.net/circuits/dimmer.htm
but do I have to use a neon lamp for L2 or can I just leave it or use something else also that is a 40502 triac what exactly is the rating of that piece.

That circuit is effectively the same as David posted, except it uses a neon instead of a diac, and doesn't include supression components - you really need to include them, dimmers are VERY noisey things.

Any mains suitable triac of sufficient current rating would be fine.

 

[sammy004]

What are supression components and where do I add it in the circuit. also does my diac need to be a specific rating.

 

[Nigel Goodwin]

What are supression components and where do I add it in the circuit. also does my diac need to be a specific rating.

The choke and the 47nF are the suppression components in David's circuit, diac's are generally fairly standard, intended mainly for this exact purpose - triggering a tric or SCR.

 

[Misterbenn]

could some one explain what a diac is please.
and what there used for?

from the circuit above i can see its used to trigger the TRIAC, why?

 

[sammy004]

could some one explain what a diac is please.
and what there used for?

from the circuit above i can see its used to trigger the TRIAC, why?

I want to know to!!
Also I am going to use this circuit https://www.aaroncake.net/circuits/dimmer.htm
cause I already started it where would I add the additonal components explained above.

PS Misterbenn what is a resistor?

 

[zachtheterrible]

PS Misterbenn what is a resistor?

It resists current. It's those squiggly lines on the schematic.

 

[sammy004]

SARCASIM :lol:

 

[Nigel Goodwin]

PS Misterbenn what is a resistor?

It resists current. It's those squiggly lines on the schematic.

Only in primitive societies :lol:

The civilised world changed to rectangular boxes for resistors over 30 years ago :!:

 

[eblc1388]

While I myself use both, zigzag in hand drafting and box in schematic capture, this is what the authors of AOE said:

**broken link removed**

We were amazed to discover that foreign language publishers generally redraft the figures, using funny little boxes (instead of handsome zigzags) for resistors, etc., then festooning the things with unpronounceable labels and captions.

Takes your pick.

 

[GABI MIHAI]

if it is not too late try this PIC12F675 dimmer
' 1MHz*64=64usec ca si tact
' 0.01/64usec=156,25 pasi
' deci Mindelay=0 si maxdelay=156 pentru 50Hz
' in acest caz prescallerul este 64 deci OPTION_REG=0x0x0101
' in acest caz bitul de overflow este INTCON.2 si se curata soft
' resetul TMR0 se face soft
' incarcarea TMR0 se face soft
' merge face sesizare intreruperi si tot restul! E FAIN!
' INITIALIZARE MCU
'
' initializare TS pe porturi
TRISIO = %00001111
'
OPTION_REG=%10000101 ' Enable pull-ups a fost 11000101
WPU=%00000111 ' Enable pull-ups on GP0, GP1
CMCON=7 ' Disable analog comparator
ANSEL=0 ' Disable analog converter
IOC.2=1
' initializare intreruperi la start numai cele pe GPIO2/INT
INTCON=%01011000
Pb_Inc var GPIO.0 ' Input for INCREMENT/ON push button
Pb_Dec var GPIO.1 ' Input for DECREMENT/OFF push button
ACline var GPIO.2 ' Input for the FullWave rectify AC line
Triac var GPIO.5 ' Output to TRIAC gate
Led var GPIO.4 ' Led output
delay var byte
onoff var bit
count_up var byte
count_dn var byte
maxbright var byte
minbright var byte
pas var byte
stare var bit
var1 var byte
prag var byte
pas1 var byte

maxbright=230
minbright=90 ' a fost 100
triac=0
delay=minbright
pas=20 ' a fost 25
pas1=2
onoff=0
count_up=0
count_dn=0
stare=0
var1=0
prag=6
on interrupt goto intrerupere
'
loop0:
gosub sunet1
triac=1
pause 500
triac=0
pause 500
triac=1
pause 500
triac=0
gosub sunet2
'
loop1:
' rutina de lighton
if pb_inc=0 or pb_dec=0 then
gosub sunet1
onoff=1
repeat
if stare=0 then
delay=delay+1
stare=1
endif
until delay=maxbright
else
goto loop1
endif
'
start:
' rutina de dimmon si dimmoff
if delay<=minbright then
onoff=0
'goto loop1
else
onoff=1
endif
if pb_inc=0 and delay<maxbright then
if stare=0 and count_up>=pas then
var1=var1+1
if var1=prag then
delay=delay+1
var1=0
endif
count_up=25
stare=1
else
endif
else
if count_up>pas1 and count_up<pas and delay<maxbright then
' count_up=0
goto lighton
else
endif
endif

if pb_dec=0 and delay>minbright then
if delay=(minbright+1) then
goto start
endif
if stare=0 and count_dn>=pas then
var1=var1+1
if var1=prag then
delay=delay-1
var1=0
endif
count_dn=25
stare=1
else
endif
else
if count_dn>pas1 and count_dn<pas and delay>minbright then
' count_dn=0
goto lightoff
else
endif
endif
goto start
'
'
'
lighton:
repeat
count_up=0
if stare=0 then
delay=delay+1
stare=1
endif
until delay=maxbright
goto start

'
lightoff:
repeat
count_dn=0
if stare=0 then
delay=delay-1
stare=1
endif
until delay=minbright
onoff=0
gosub sunet2
goto loop1


sunet1:
sound led,[102,5,104,5,106,5,108,5,110,5,112,5,114,5,116,5,118,5,120,5,122,5,124,5,126,5]
return
'
sunet2:
sound led,[126,5,124,5,122,5,120,5,118,5,116,5,114,5,112,5,110,5,108,5,106,5,104,5,102,5]
return
'
disable
intrerupere:
' pe acline
if INTCON.1=1 then
INTCON.7=0
INTCON.1=0
TMR0=delay
INTCON.5=1
INTCON.4=0
INTCON.7=1
stare=0
led=not onoff
else
endif
' pe TMR0
if INTCON.2=1 then
INTCON.7=0
INTCON.2=0
if onoff=1 then
triac=1
else
triac=0
endif
if pb_inc=0 then
count_up=count_up+1
else
endif
if pb_dec=0 then
count_dn=count_dn+1
else
endif
if pb_inc=1 and pb_dec=1 then
count_up=0
count_dn=0
endif
triac=0
else
endif
INTCON.7=1
resume
enable