Is there a way that I could use a usb port to power on some 120 V devices ?
All I could think of is a relay that used the usb voltage for power.
I want other things to go on and off along with my laptop.
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I have been looking at the various offerings for a rear turn signal light.
I see many for $6 - 10, but feel that you get what you pay for.
Most drivers/LEOs don't even know the turn signal hand signs.
Any recommendations would be appreciated or even other options for visibility.
I have plenty of candle power on my front. :-)
Anyone used one of those rear lights that have 2 laser beams ?
Thanks,
Andy
USB -> FTDI chip -> microcontroller (ATmega) -> optocoupler -> relay -> 120 V device.
Write a windows application and write a program for the microcontroller to communicate with each other to control the relay.
Thanks, it's an interesting method.
Andy
before laptops, they made devices that sensed current flow in the 120 vac line
so - you turn your computer on - and the monitor came on with it
of course, many computers back then had aux 120 vac outputs on the power supply
what you want is called an SSR - solid state relay
it already has the optocoupler that Marinus mentions, built-in
they may be controlled by logic-circuit DC voltage levels
and - they may switch larger DC and/or AC loads
USB is a 0 to +5 VDC thing - so you want something in that range
"high" power example
http://www.digikey.com/product-detail/en/DC60S3/CC1126-ND/221844?WT.mc_id=PLA_221844 (http://www.digikey.com/product-detail/en/DC60S3/CC1126-ND/221844?WT.mc_id=PLA_221844)
low power example
http://www.mouser.com/Search/Refine.aspx?N=4292890524+18383556 (http://www.mouser.com/Search/Refine.aspx?N=4292890524+18383556)
oh - and if you already happen to have a mechanical relay on hand....
use a low-power SSR to turn that off and on
then use the mechanical relay to control the load
that way, you get the click sound you are so badly looking for :P
Thanks, I drew a blank on the contact form and output device columns.
It would probably just be used for a small computer case cooling fan.
But if the price isn't that much more, I would use a 10 A model.
I just thought of something. Could I step up the usb voltage to power that fan ?
It draws .14 Amp.
Andy
you can set the FTDI chip to get 0.5 A from the USB port.
i believe the USB port only provides +5VDC, though
i would guess the fan runs on +12VDC, or maybe 120VAC
of course, you could just buy a laptop fan that is designed to be run on 5VDC :P
http://3acyber.en.alibaba.com/product/258040462-200936039/USB_Folding_Fan_Laptop_Cooler_Pad.html (http://3acyber.en.alibaba.com/product/258040462-200936039/USB_Folding_Fan_Laptop_Cooler_Pad.html)
here's one that has a feed-thru USB
http://www.dhgate.com/product/usb-mini-octopus-laptop-notebook-2-fan-cooler/141104033.html (http://www.dhgate.com/product/usb-mini-octopus-laptop-notebook-2-fan-cooler/141104033.html)
I already have a custom cooler that uses a Class 2 transformer, it ain't pretty but works.
Dave,
I think a step up transformer and some zener diodes might get er done.
Andy
ok - be sure to wear safety glasses - lol
Do you wear safety glasses when soldering ?
I wear regular glasses all the time.
Andy
no - i'm sure i've violated most safety rules, as related to electronics - lol
but - i wasn't talking about soldering - i was talking about when you plug it in