Hi everyone:
Extreme newbie here.
I'm trying to finish the Chipamp.com LM3886 dual mono projects I was working on for ages.
How does one figure out what current rating power switch you need for your amp to avoid arcing, or any other issues? Is it based on the maximum current draw of the transformers when you first turn on the amp?
I'm using some inrush protection circuits with my amp. I assume that will affect the switch's current rating?
Again, extreme newbie, so please make it simple, if you can.
Thanks
Extreme newbie here.
I'm trying to finish the Chipamp.com LM3886 dual mono projects I was working on for ages.
How does one figure out what current rating power switch you need for your amp to avoid arcing, or any other issues? Is it based on the maximum current draw of the transformers when you first turn on the amp?
I'm using some inrush protection circuits with my amp. I assume that will affect the switch's current rating?
Again, extreme newbie, so please make it simple, if you can.
Thanks
Look at what is available. I like using double or even triple pole switches. Then parallel the contacts to increase the current capacity.
I like the mini size, and 5 amps. This rated current capacity is steady state. Instantaneous inrush current is always orders of magnitude more.
I like the mini size, and 5 amps. This rated current capacity is steady state. Instantaneous inrush current is always orders of magnitude more.
you need to work out how much power your amp is taking.
then watts/mains voltage times 1.5 will give switch amp rating.
an old mobile disco trick was to put 100nf 220vac cap across switch to soak up any arcing.
this stops any interference caused by arcing.
then watts/mains voltage times 1.5 will give switch amp rating.
an old mobile disco trick was to put 100nf 220vac cap across switch to soak up any arcing.
this stops any interference caused by arcing.
Okay, I understand that. Do I just have to know the maximum current of the input transformers then?
And do two take twice as much as one if I'm using two transformers?
And do two take twice as much as one if I'm using two transformers?
Large transformers are tough loads to switch athough if I'm honest I've never seen any guidelines or documentation to aid in selecting one.
Lets say you have around 400va of transformer, either a single or two of 200va. I would be looking at a switch rated 15 A at 250 Vac.
http://www.farnell.com/datasheets/54418.pdf
Lets say you have around 400va of transformer, either a single or two of 200va. I would be looking at a switch rated 15 A at 250 Vac.
http://www.farnell.com/datasheets/54418.pdf
One amp has two 160VA transformers. Another has two 300VA transformers.
Do theyeven make round push button anti-vandal type switches with those current ratings?
Do theyeven make round push button anti-vandal type switches with those current ratings?
(2*160)/110=2.99 A. I would go for 6 or 10A rating with arcing capacitor.
Or use a high Amperage relay 16-20A to handle the load & use a small switch to power the relay.
Or build a inrush current delay with a relay. A resistor is placed in series with the transformer & then after a few milliseconds shorted by the relay.
Or use a high Amperage relay 16-20A to handle the load & use a small switch to power the relay.
Or build a inrush current delay with a relay. A resistor is placed in series with the transformer & then after a few milliseconds shorted by the relay.
Since most of our AC outlets (breakers) are 15 amps, thats a very common value switch. Thats what I would use.
Thanks. Do people recommend using DPST switches for safety of people and protection of the gear?
Thanks
Thanks
I wouldn't imagine so but you could still use these to control a Triac and switch the load that way.
This is one of Nelson Pass's designs from the A75 (I think). The switch only passes a very low current.
Use of DPST switches isn't a requirement as long as the basic design follows all the safety rules.
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Sooo..I did some browsing at Mouser and wow, I couldn't find much. The problem is I bought a HIFI2000 case, and didn't take into account the massive 10mm thick front panel. The only vandal resistant style switches I could find that were long enough to go all the way through a 10mm hole were $CAD 88.00 each. I need two. Ouch!
Is there any other type of switch that looks nice that would be that long? I hate rocker switches. To me they look way too industrial. I'd prefer something that lights up and takes AC voltage for the light, but at this point, I'd give that up too if I had to.
Is there any other type of switch that looks nice that would be that long? I hate rocker switches. To me they look way too industrial. I'd prefer something that lights up and takes AC voltage for the light, but at this point, I'd give that up too if I had to.
Thanks. Good advice, but due to my chronic health condition, I really can't do anything right now. I have to pay someone to do everything. And I'm trying to keep things simple. Other people are using the same case here no? The Mini Dissipante 400mm?
Switches especially designed for transformers and motors have an in-rush rating as well as a steady-state rating.
Are many people here on DIYA using vandal-resistant type switches for their appearance, or something a little more ummm....industrial looking.
The funny thing is, I don't need any vandal resistant features. Those switches just happen to be nice looking in my eyes.
The funny thing is, I don't need any vandal resistant features. Those switches just happen to be nice looking in my eyes.
Hmmm....no reply to that last post. Well, do I need to buy from the fancy manufacturers like Schurter, e-switch etc. or are there cheaper anti-vandal switches that are good quality (reliable)?
You would have to study the data sheet for any switch you like the look of... and most anti vandal switches have momentary rather than latching contacts remember. I just had a quick look at a supplier and all I saw were for low voltage rather than mains.
If that's the case, then I'll consider getting a machine shop to bore out a portion of the front plate so that the switch is countersun within that. Any idea approximately how much a machine shop might charge for drilling a, say, a 16mm hole and milling/drilling out a larger rebate on the front for that to fit?
Unless there's another type of power button that looks nice.
Unless there's another type of power button that looks nice.
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