Precise linear optocoupling

MorganS:
Have you ever looked at ...

Thank you for preaching and justifying today'd electronic engineering for not having what is exactly needed or desired.

Various posters have pointed out that what you exactly require is impossible without great power loss.

A variac with motor control night achieve your needs.

But far more expensively than a triac approach for a heating element.

Allan

Well ok, but unfortunately the project I am working on apparently needs a linear change of the AC in time.
I am just designing that for some complex heating process of ceramic and other materials that may take even few days and involves some complex profiles. This looks very difficult and I see there is no easy solution. Any fast switching with such power causes all kinds of EM interference. I will look at SCR and maybe some triacs that may be somehow adjusted to linear dimmers. Maybe there are some other silicons suitable for that.

Why do your ceramics care about E-M radiation?

He is lost in the jungle , he is expecting that TV set will work at 10V AC - similar electronics is inside of induction stove....
He is crying no simple solution - look at my posts

MorganS:
Why do your ceramics care about E-M radiation?

There is some various em sensitive measuring equipment around.

Deous:
There is some various em sensitive measuring equipment around.

Doesn't answer the question.. :o

"Around" where?
In your "laboratory"/"workshop"?

Tom.... :slight_smile:

10m - or more, this is how far interferences can go from 1000W, 100 kHz square wave transmitter

ted:
10m - or more, this is how far interferences can go from 1000W, 100 kHz square wave transmitter

''

Couple it to a decent antenna and it'll be detectable continents away.

It's called longwave radio.

Chopped ac -ie with a triac and reasonable suppression ( common mode chokes, X rated caps etc) , not very far. and eg Murata make excellent mains noise suppression gadgets based on such techniques..

You can buy solid state relays with which you can play such tricks and contain such suppression devices for reasonable prices.

Allan

Good idea thanks. Switching those power elements on and off many times really affects some work on rf stuff in that small lab ) Anyways I ordered couple of power triacs and will try to experiment with them.

induction stove power module is not a resistive load for triac

No, but the OP says he's going to use a resistive heating element - or do I misunderstand you,Deous?

And if you're going to use a triac with suitable suppression devices, check out this forum for threads on variable phase ac control. It's been done many times before and gives you effectively near analog control with good resolution.

Allan

So many times he changed his mind so I don't know what he is doing, and misleading name of the thread ......

Hi,
@Deous, have you finished any of the projects from your previous threads?

Tom... :slight_smile:

And ( a thought )

Deous : how do you expect to heat a ceramic with induction heating? - they're insulators.......

Allan

I just came back with update:
Replacing that mosfets in series with triac works perfect.
Circuit needs ac cap though - oven also flashes sometimes at different frequencies
All works perfect because triac requires really small voltage - 0.6-0.9V to switch on

Hi,
Good to hear.

Can you please post a copy of your new circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom.. :slight_smile:

It is the same picture as posted one in this thread. Additionally I found out an easy way how to generate a PWM signal using ESP32 that can be adjusted from 1Hz to 10MHz ))
It is perfect to control all kinds of devices. Posted code on other forum

Deous:
It is the same picture as posted one in this thread. Additionally I found out an easy way how to generate a PWM signal using ESP32 that can be adjusted from 1Hz to 10MHz ))
It is perfect to control all kinds of devices. Posted code on other forum

Sorry this is what you posted? ? ?


PLEASE a hand drawn complete circuit diagram please, to help complete this thead for anybody looking for solution to similar problem they may have.
Thanks.. Tom.. :slight_smile: