Hi Folks!

I'm quite excited to join here today.

I'm new to power electronics and out of interest working on a simulation on a 32Vac line driving a low power load (less than 30W). I'd like to control negative and positive sinewave cycles going to the load and chose what cycle to go next. For example I might have 10 full normal cycles going, and then at some point choose to send 2 negative cycles in a row. Ideally I'd like to have full control over pattern. Only requirements is this to happen in zero crossing and the switching time to be no more than 1ms, ideally in microseconds scale.

I looked at it as if I am multiplexing an AC source line and swapped polarity version of it onto the load with some magical AC line multiplexer.

I'm wondering:

1. Is there anything fundamentally wrong with switching polarities to any load?

2. What's the best and cheapest way to implement this?

2. Assuming use of TRIACs there any circuit which achieves the same job?

Here is the most simplified simulation in LtSpice I could come up with to have a go:

Though it's not working as I expect:

versus something similar to expected output trace:

I appreciate if anyone with more insight shed a light and point me in right direction to follow or any component that makes this happen. I've attached simulation and data if anyone wants to have a look.

Cheers,

Matt

I'm quite excited to join here today.

I'm new to power electronics and out of interest working on a simulation on a 32Vac line driving a low power load (less than 30W). I'd like to control negative and positive sinewave cycles going to the load and chose what cycle to go next. For example I might have 10 full normal cycles going, and then at some point choose to send 2 negative cycles in a row. Ideally I'd like to have full control over pattern. Only requirements is this to happen in zero crossing and the switching time to be no more than 1ms, ideally in microseconds scale.

I looked at it as if I am multiplexing an AC source line and swapped polarity version of it onto the load with some magical AC line multiplexer.

I'm wondering:

1. Is there anything fundamentally wrong with switching polarities to any load?

2. What's the best and cheapest way to implement this?

2. Assuming use of TRIACs there any circuit which achieves the same job?

Here is the most simplified simulation in LtSpice I could come up with to have a go:

Though it's not working as I expect:

versus something similar to expected output trace:

I appreciate if anyone with more insight shed a light and point me in right direction to follow or any component that makes this happen. I've attached simulation and data if anyone wants to have a look.

Cheers,

Matt