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Two circuits ... Two questions

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joe2005

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I am a beginner at this but I am doing some circuits and I have those questions:

1- I need a device/circuit that acts exactly like a relay ie. when a little DC volt is applied is closes another circuit. The this is that I don't want to use a relay due to its sound (yes I have frequent switching). I want this device/circuit to be able to allow both AC and DC signals through up to 220VAC and to be able to handle at least a couple of Amperes. Any Suggestions...pleeaaaaaase

2- I am trying to build a circuit that acts as a switch between the 220VAC mains and a light bulb. Simply put, the light is off and you press the button, the light bulb gradually lights up until it reaches its max in 10 seconds. The lights is now on and you press the button, the light gradually fades in 10 seconds. I don't care to change a thing in the "steady state" part between the on and the off. Now the thing is that I do NOT want to use a variable resistance. I only want a simple "click". Please give me all the ideas possible.

Thank you alllllllllllll Smile :)
 
joe2005 said:
I am a beginner at this but I am doing some circuits and I have those questions:

1- I need a device/circuit that acts exactly like a relay ie. when a little DC volt is applied is closes another circuit. The this is that I don't want to use a relay due to its sound (yes I have frequent switching). I want this device/circuit to be able to allow both AC and DC signals through up to 220VAC and to be able to handle at least a couple of Amperes. Any Suggestions...pleeaaaaaase

What you're describing is a relay - and that's what you need. There are ways to do what you want using solid state methods, but not that will meet all your criteria at the same time.

2- I am trying to build a circuit that acts as a switch between the 220VAC mains and a light bulb. Simply put, the light is off and you press the button, the light bulb gradually lights up until it reaches its max in 10 seconds. The lights is now on and you press the button, the light gradually fades in 10 seconds. I don't care to change a thing in the "steady state" part between the on and the off. Now the thing is that I do NOT want to use a variable resistance. I only want a simple "click". Please give me all the ideas possible.

I would suggest the use of a micro-controller (probably a PIC), or you're getting too complicated.
 
What you need for part1 is a "solid state relay".
This will do all the things an electro-mechanical relay will do but there are no moving parts, so it wont click and clack as it is operating.

I cant make a sensible suggestion as to where you can get one as I dont even know which continent you are on.

JimB
 
Hi all and thanks for replying

Nigel, My problem with the relay is its sound, and can u please elaborate on that PIC idea.

JimB, I am on Asia ;)
 
joe2005 said:
Hi all and thanks for replying

Nigel, My problem with the relay is its sound, and can u please elaborate on that PIC idea.

JimB, I am on Asia ;)
A PIC (or any micro) can be used to generate a delayed triggering signal (which is used in electronic fan controllers /light dimers) to 'chop-off' the AC signal - which changes the power delivered to the buld(incandescent)
pls see
https://www.electro-tech-online.com/custompdfs/2006/06/91094A.pdf
https://www.epanorama.net/documents/lights/lightdimmer.html
 
JimB said:
What you need for part1 is a "solid state relay".
This will do all the things an electro-mechanical relay will do but there are no moving parts, so it wont click and clack as it is operating.

But as I said above, it WON'T meet all his requirements - solid state 'relays' are generally for AC switching only - AC is required so it can turn OFF again.
 
AC is not *required* as there are many "DC solid state relays" around. Most probably just some sort of high voltage semiconductor(NPN, MOSFET etc...) with input conditioning.

Try Google "DC Solid state relay" and you will get many hits. Or try the following link for an example.

https://www.electro-tech-online.com/custompdfs/2006/06/RD0605D.pdf

DC Solid State Relay
Rated operational current: 1 and 5 ADC
Operational voltage range: Up to 350 VDC
Input range: 3 to 32 VDC
Insulation: OPTO (input-output) 4000 VACrms

But, a big but, it will not work with AC. :)
 
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eblc1388 said:
But, a big but, it will not work with AC. :)

Which is what I said, you can't meet his specs with a solid state relay, he needs to either use a normal relay?, or limit his specs somewhat!. Generally there wouldn't be a requirement for both AC and DC, but as he's given no clue as to what he's doing it's difficult to make suggestions!.
 
I am wondering if you have worked with scr or color organ circuits.Way back
during the late 60's early 7o's we played with scr's to turn lights on and off useing small audio transformers to pulse scr's in 110 vt lights' the scr in dc
circuits would latch on,you'd need a switch in series with the load,to open the
the latch, but in ac loads no switch was needed because the loadsine wave would drop when sine wave went negative withwith respect to ground.I probably have not made this very clear but look at some scr data,may be it might give you some ideas. good luck,tom ne6ao
 
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