[RFI] No RFI/EMI Filtering on triac ...

[Roger (K8RI)]

On 4/15/2014 12:09 PM, David Cole wrote:
> It is even stated as being RFI noisy...  I wonder if it is Part 15
> compliant?
>
It's a component. AFAIK components have no requirements.

I've built many Triac and SCR controllers. Typically they use a Diac to 
trigger the on state on each half cycle.  The trigger pulse is something 
to behold. If not thoroughly suppressed They will trigger other similar 
devices in the same building.
I see that this device is the very basic Triac, Diac device shown  in 
the original book back in the 60s or 70s.  "I think" it was a book by 
GE, but not sure.  It's been a long time.

I started with a basic circuit for a 3 phase, resistive heater(furnace) 
  The first try was like a Keystone cops movie.  Turn one section up. 
All OK. Turn the second section up...The first may increase or decrease 
as the second one goes up. Add the third section. Both the 1st and 2nd 
sections may go up or down, or...one may go up and the other down.

My amp uses a Triac, soft start.  You can hear it on every receiver in 
the station as a 120 cycle series of pulses going BBBuuurrrrrppp. as it 
starts, but it's only a couple seconds.  However, that's typical of both 
Triacs and SCRs with out filtering.

Fortunately, no one sells one (that I know of) with a non zero crossing 
turn off.  That takes a reverse pulse that momentarily reduces the 
current to a very low value.  I don't know if that could be suppressed.

73

Roger  (K8RI)