Need a Triac; haven't got one!

Well, you're giving it 3 times the design voltage, so yeah, at 3 times frequency it'll work.

There's a lot of over-thinking going on here. Manufacturers make snubbers for applications just like this. They consist of a resistor and a capacitor in a single encapsulation. They even mark the values used on the outside. A typical value is 120R + 0.1uF. I suggest you just make a snubber up yourself from discrete parts using these values. Forget about simulating it and all that nonsense. Just make the damn thing up already FFS.

Do these things have snubbers built-in? (I'm guessing they don't right?)

Where's the 1/3 AC line frequency going to come from, pray tell? Anyway, I've already established at what operating conditions it runs fine at, so no further investigation required.

What the blazes are you trying to suggest here??

at

LOL- overthinking...circuit sims of this type are a snap. The sim results a ppear about right although it's impossible to tell if the cmd line syntax a re right from the undecipherable directory...

Version 4 SHEET 1 880 680 WIRE -32 176 -112 176 WIRE 80 176 48 176 WIRE 352 176 160 176 WIRE 352 272 352 240 WIRE -112 304 -112 256 WIRE 352 368 352 352 FLAG 352 368 0 FLAG -112 304 0 SYMBOL cap 336 176 R0 SYMATTR InstName C1

SYMBOL res 176 160 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R1 SYMATTR Value 4K SYMBOL ind 64 160 R90 WINDOW 0 5 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName L1 SYMATTR Value 10H SYMBOL voltage -112 160 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value SINE(0 315 50 0 0 45 1) SYMBOL res 336 256 R0 SYMATTR InstName R2 SYMATTR Value 100 TEXT -144 360 Left 2 !.ic V(C1)=0 I(L1)=0 TEXT -144 328 Left 2 !.tran 0 20m 0 0.1U startup uic

The magnetic flux allowable in an inductor has a limit, which causes the iron to completely magnetize (and no further magnetization response is possible). It's this saturation limit, which (because flux is integral of voltage over time) is expressed in volt-seconds, which will not be violated.

Three times the voltage and three times the frequency means the same flux (same volt-seconds applied) in one half-cycle, before the AC reverses.

That doesn't mean the mechanics of the bell will work at 60 Hz rather than 20 Hz. The clapper is on a spring which may be tuned to resonate at 20 Hz. But he said he tried it and it worked, so that's the end of that.

Yes, it's been exhaustively tested and is working great as it is. End of.

Any standard electronics components store should have BT136. It is a rugged device and we have used it for various projects.

Can't get it to load. Get "Aborting. Unknown schematic syntax" message.

It runs here as posted.

It looks like a disaster to me. Peak output voltage is 564V at the first peak. That's greater than the line voltage of 315V.

Sometimes the idiot program has problems with that "mu" for C1, even though

ATTR Value 0.01U" -see if that helps.

DOW

Holy cow, batman! Whatcha gonna do 'bout it?

No it doesn't. The bit that causing the problem appears to be this line:

That's the part that comes up immediately following the 'unknown schematic syntax' in the error message. Sadly I'm not versed well enough in LTS formatting rules to spot irregularities.

That just results in the bell ringing continuously so these values are obviously incompatible with a 50Hz signal to a 4kohm load. It's effectively bypassing the triac altogether!

Sounds like a line wrap problem. Some people don't know how to post and retain proper line wraps ;-) ...Jim Thompson

Julian, It would appear that it's your reader causing the wrap issues. I copied it and loaded it to LTspice, no sweat. ...Jim Thompson