Optoisolated Triac Water Heater Controller

[Moniker]

Eric,

You are right on. And, "Duh," my little boiler has a mechanical thermostat on it for that very purpose already!

Your asp file loads right up of but, of course, does not show components not in the LT library.

Now all I have to do is learn how to use the new components in LTSpice.

Thanks

moniker

 

[Moniker]

Hi All,

Attached is the result of your help and my efforts. I was able to use Eric's information to learn quite a bit about LTSpice. But I have yet been able to install non-LT components into the program! Nevertheless, I have obtained some decent results.

The attachment will show that I have decided to go off board with a zerocross SSR. It is more expensive, but easier for me to model. You will see that the circuit simulates nicely with a few ms of hysteresys. The hysteresys is very easy to see when simulating different positive feedback resistors.

I added an additional cap to shunt spikes the hysteresys may not avoid. I am not sure the cap is necessary or of appropriate value. Opinions?

While the circuit simulates well, the real world may well be different. So, if you see component values that might be modifed for better stability and longevity, please let me know.

Thanks for all the help you all have provided and special thanks to Eric who helped me get into working with LTSpice.

moniker

 

[ericgibbs]

hi,
The LTS sim looks OK, nicely done.
Did you join the Yahoo LTspice users group, free, with lots of models.
If you want to change the plot background colours, use the LTS control panel.

 

[Moniker]

Hi,

Yes I did join the LTSpice users group. There are lots of models available, but I have yet to figure out what the various installation routines mean. Time will tell I guess.

Thanks for the tip on the background colors. It is a breath of fresh air to have a white background on the graphs.

BTW, I have tried many free PCB programs and they mostly do not get the job done for me. The commercial free ones give little flexibility regarding mirroring the layout so that I can make the board myself. Even if I mirrored the plan in my head and drew it that way, they tend to print black with a ton of tiny holes so that if you use their product to make your own board, the traces would be too porous to use. I have considered using my very old version of Paint Shop Pro, but that would require me to make up a bunch of components and to go through a tedious set up to properly scale the drawing. That is a pain in the a**. Any suggestions for decent PCB drawing software?

Thanks for all the help.

moniker

 

[Moniker]

Hi,

Here is the above graph with a white background. Perhaps it is due to my old eyes, but it looks better and is easier to read to me. The hysteresys is easier to see and estimate re: time too.

Thanks

moniker

 

[ericgibbs]

Hi,

Here is the above graph with a white background. Perhaps it is due to my old eyes, but it looks better and is easier to read to me. The hysteresys is easier to see and estimate re: time too.

Thanks

moniker

hi,
Its a lot easier to read, [it also save a LOT of black ink if you ever need to print a plot] have you found that you can also make the plotted lines thicker, also the text size etc, use the Control panel.

For simple pcb and schematic work I use expresspcb , a free web download, also if you get a free copy of ScreenHunter 5.1 you can copy a section of the PC screen to a gif file.
Use your favourite image program to flip/mirror the gif images, I use the Paint shop Pro.

Ref the models from Yahoo LTS, while you are learning, keep the group of files you download for a particular device in its own folder.
Later on you can shuffle them around into their correct folders.



https://download.cnet.com/ScreenHunter-Free/3000-2192_4-10063246.html

 

[Moniker]

HI,

Well I had already downloaded the Express package and used it in my first schematics. I find it the best of the free packages but was hoping for better. Following your advice of dealing with the control panel, I now have a really useful program. Thanks.

I too use a very old copy of PSP 9 to do my image manipulation. It is a real workhorse that works for me. Great program that.

I d/l Screen Hunter. It looks like a neat program. I will have to play with it some. Thanks.

As for dealing with LTSpice models, well, that will have to wait until I need models they do not have. Spending $15 rather than $3 for the same results is not what I live for. But I would rather do that than spend days on end figuring out how to install the new components into LTS.

Thanks for your help Eric. You are a gentleman and a scholar!

moniker