Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

:: Smoothing 240V Bulbs ::

Status
Not open for further replies.

suby786

New Member
Odd question it may seem.

I have 4 triacs controlling 4 240v AC bulbs.

The triacs are controlled by a PIC, with 0.5ms intervals. When i change the triac firing to the next step (0.5ms away) there is obviously a drop/or increase in brightness as you'd expect but its very notcy as you also would expect. Without changing from 0.5ms intervals, i want to smooth the output so the change is GRADUAL rather than NOTCHY

Im ok with 12V AC having capacitors after the rectifier, but not with 240v, i dont want to rectifier anything so where would i put a capictor, across the HOT and NEUTRAL? stupid answer i guess your gonna say

Please advise... also what type would you recommend and rough value, i want the delay to be roughly 1second long before it settles to its new brightness value.

By using capacitors i will get the soft dimming when im going DOWN in brightness, but going up i will still have the notches? meaning doing the work in software is the best bet (but its soooo long winded)
 
Capacitors won't help with soft dimming in either direction. The AC alternates at 50 Hz which is much faster than your desired 1 second.

You really can't avoid changing the PIC code.
 
Ok so code change it is... but how would i go about it, i have alot of code to do 20 x 0.5ms intrvals to make up 10ms cycle, to reduce the notchyness i'd need 0.1ms meaning ill need 100, so 5 x's the code. thats ALOT of code, i already have 1300 lines so far.

If i keep the 20 stages, and say if i want to jump from step 4 to 5, when i send the command to jump to 5, i gradually increase the steps at each 10ms (every half cycle of AC) so it seems its getting dimmer slower...

any other innovative ideas?
 
You are apparently doing the timing in straight-line code. To get finer steps with reasonable code size, you could consider either timers or loops.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top