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Is there such thing as a "dimmable relay"?

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alokw

New Member
Is there a device out there that (when attached to 120VAC) does the following:

- When Pin A receives 5 VDC, Pin B outputs 120VAC
- When Pin A receives 2.5 VDC, Pin B outputs 60VAC
- When Pin A receives 1.25 VDC, Pin B outputs 30VAC

You get my drift... the dimming should happen pretty gradually -
basically, I'd like to hookup Pin A to an Arduino, and Pin B to a light bulb, and be able to have the Arduino dim the light bulb, up and down, as I program it to.

Any thoughts?
Thanks!
 

duffy

Well-Known Member
Not that I'm aware of. This is done with the widths of the pulses, specifically the ratio of the width of the "on" pulse to the "off" pulse. It's called "pulse width modulation", and even the potentiometer in a lamp dimmer is operating these pulses, not a fixed DC voltage.
 

tcmtech

Banned
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Sure is such a device! crydom makes one that is 0-5 volt proportional controlled. Check out digikey.com Look under solid state relays. Other manufactures have them too!
 

duffy

Well-Known Member
Thanks, tcmtech. My apologies, alokw - you can get them from Digikey. Search under Solid State Relays -> Crydom -> Voltage Controlled.
 

tcmtech

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Some days I am almost useful! But just some.
 

audioguru

Well-Known Member
Most Helpful Member
A lightbulb is a high power heater that makes a little amount of light.
Use an LED that makes a lot of light and a little amount of heat.

It takes a huge amount of power to make heat.
 

tcmtech

Banned
Most Helpful Member
Does "alokw" stand for something? or was the typing just that far off?
 

alokw

New Member
Haha, thanks for all of the replies - very helpful indeed.
Alok is actually my first name, and W is my last initial = alokw

Thanks again!
 
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