yes , I acknowledge that - this is not a dimmer. I just like the smooth analog inrush
ramp I see on my present setup. Any proposed layout would also have reduced
radiated field (than a relay/resistor setup) - if compact.
My only issue would be future serviceability. Any relay will work , would the triac
be a "special one" ? (as easy to source).
Triacs on a separate board would give the flexibility of relays , to integrate them
on the main board might create other problems.
So , considering these factors , will going SS really bring a lot to the table besides
size ? (I am sold on the SS speaker relays
).OS
A triac assisted relay is another solution.
I was involved with an electric cooker project many years ago that used that and the relays lasted much longer.
A triac should in theory last forever, a relay has a limited life as the contacts will burn on each operation, although its life could be extended many times by using a triac in parallel.
I was involved with an electric cooker project many years ago that used that and the relays lasted much longer.
A triac should in theory last forever, a relay has a limited life as the contacts will burn on each operation, although its life could be extended many times by using a triac in parallel.
I plan to build a power distribution module with easy to get triacs instead of relays. It will be separate from everything else. I want a mains in connection and transformer out connection. On board inrush resistor(if needed) and fusing. Either 12VAC or 120VAC out to the protection board too. No wire running between relays and resistors.yes , I acknowledge that - this is not a dimmer. I just like the smooth analog inrush
ramp I see on my present setup. Any proposed layout would also have reduced
radiated field (than a relay/resistor setup) - if compact.
My only issue would be future serviceability. Any relay will work , would the triac
be a "special one" ? (as easy to source).
Triacs on a separate board would give the flexibility of relays , to integrate them
on the main board might create other problems.
So , considering these factors , will going SS really bring a lot to the table besides
size ? (I am sold on the SS speaker relays
OS
It will hum no more with a triac than from normal mains.
The triac switches on at mains zero volts crossing.
You might get a minimal amount of noise when the phase control is done.
Motors are run off triacs all the time and they are just inductors like a transformer.
Your washing machine motor will be controlled by a triac.
The triac switches on at mains zero volts crossing.
You might get a minimal amount of noise when the phase control is done.
Motors are run off triacs all the time and they are just inductors like a transformer.
Your washing machine motor will be controlled by a triac.
That's good to know! This is something I want to avoid. Possibly your driver isn't firing the triac on properly?
He is talking rubbish !
A triac is a short when on full power !
So how can it cause hum ?
As I said I'm new to triacs but if they are anything like triggering a mosfet he possibly might not be turning it on fully or quickly enough.
Is there a hum without the solid state relay ?
If there is any DC on the mains it will upset a toroidal transformer and make it hum.
Hi,
Yes, you can heard the hum from the transformer without the relay. Once the triac it is bypass the transformer run completely quit. I was thinking to try to filter it with a transformer snubber but since I used the triac to ramp the AC up/down on power ON/OFF I decided the best to do it is bypass it once the amplifier it is ON. Also it will eliminated the switching noise coming from the triac.
Yes, you can heard the hum from the transformer without the relay. Once the triac it is bypass the transformer run completely quit. I was thinking to try to filter it with a transformer snubber but since I used the triac to ramp the AC up/down on power ON/OFF I decided the best to do it is bypass it once the amplifier it is ON. Also it will eliminated the switching noise coming from the triac.
After you have ramped up the phase angle the triac will be fully on.
Once the triac is fully on it will be switching at zero volts so shouldn't be generating any noise.
Its the vertical switch on at the different phase angles that causes noise.
At phase angle 0 and 180 there is no noise generated but any other will generate noise.
The worst case is 90 degrees and 270 degrees where the voltage peaks.
Once the triac is fully on it will be switching at zero volts so shouldn't be generating any noise.
Its the vertical switch on at the different phase angles that causes noise.
At phase angle 0 and 180 there is no noise generated but any other will generate noise.
The worst case is 90 degrees and 270 degrees where the voltage peaks.
Controlling Motors and Transformers
A quote from the next link -
http://www.diyaudio.com/forums/power-supplies/176521-solid-state-relays.html
This makes me lean towards just a higher Vds opto isolated FET relay.
Triacs are more suited to resistive loads ??
Just a larger version of the already WELL tested SS speaker relay. Using
300-400V Vds common FET's , one can still find Rdson's of <.5R - sufficient
for 120-240V switching.
I looked it up 4 quantity el-cheapo power fet's - <10$ usd for all + the opto's.
OS
- FDB38N30U
http://www.mouser.com/ds/2/149/FDB38N30U-348165.pdf
2$ each - A 38A 300V SS relay you will have. Nice D-pac mounting
130A pulsed operation.
On to the relay contact "burning" question. Huh ! buffered with 20R at inrush -
nope ! Switching that last 5V for full AC - not here , either ??
Any SS relay would never even "break a sweat" or come anywhere near that
"pulsed" rating. You would get your 10^8 cycles out of (them).
Edit - unless lightning struck - another SS "weakness" .
Edit2 - would also make a good "one fits all" solution -this could be AC/speaker / or rail breaker.
OS
http://www.mouser.com/ds/2/149/FDB38N30U-348165.pdf
2$ each - A 38A 300V SS relay you will have. Nice D-pac mounting
130A pulsed operation.
On to the relay contact "burning" question. Huh ! buffered with 20R at inrush -
nope ! Switching that last 5V for full AC - not here , either ??
Any SS relay would never even "break a sweat" or come anywhere near that
"pulsed" rating. You would get your 10^8 cycles out of (them).
Edit - unless lightning struck - another SS "weakness" .
Edit2 - would also make a good "one fits all" solution -this could be AC/speaker / or rail breaker.
OS
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Rds 120m ohm vs. 48 would not be much of a factor.
.12ohm would drop a whole 2V off your 120V mains @17A- wow
OS
Hi,
Listen I do not want to discouraged any body from the using of the triac for the problem I encountered. What I want it is to let all know the problem I ran into and how I fixed it. Maybe you do not have the same problem. Just in case you encountered it. I have been working with traic for about 3 years and I have mastered and been able to ramped the AC up/down without any flickering like you are using a variac or light dimmer.
Listen I do not want to discouraged any body from the using of the triac for the problem I encountered. What I want it is to let all know the problem I ran into and how I fixed it. Maybe you do not have the same problem. Just in case you encountered it. I have been working with traic for about 3 years and I have mastered and been able to ramped the AC up/down without any flickering like you are using a variac or light dimmer.