| Re: LED dimmers [message #303706 is a reply to message #303668] |
Sun, 17 July 2016 15:16   |
A Hamilto
Messages: 4508
Registered: April 2011
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Keith V wrote on Sat, 16 July 2016 17:24hey there LED fans.
I bought some really nice, like as good as hoped, better than expected LED ceiling lights.
They are good looking and bright... too bright.
http://r.ebay.com/H905Pk
No problem, they are dimmable, so I go gets a dimmer from Super bright LEDs.
Single color dimmer with RF remote, $5.88!
https://www.superbrightleds.com/moreinfo/wireless/ldrf-8a-12-24-volt-dc-led-dimmer-rf-remote/64/367/
Great, being me, I open the control box to see if it has a common ground and... drum roll... it has a common high side and it switches the low side!
Well Dang, all my lights are high side switched.
So before I go and fish a new ground, does anyone know of a low cost high side dimmer for LEDs?
Thanks GMCrs If I am an electronic component, all I see is voltage from the input side to the output side, and current in between.
Why would it matter where I am in the circuit?
In the picture below, isn't the voltage across C and D and the current through PWM the same in both cases? How does PWM know where it resides relative to the battery and ground? In my mind it doesn't. When PWM has the duty cycle at 0%, the voltage across the other load is 0 (as well as the current), so the voltage across PWM is 12V. When PWM has the duty cycle at 100%, the voltage across the other load is 12V and the voltage across PWM is 0. Current is what it is. Voltages for duty cycles in between 0% and 100% are what they are.
Numbers remain the same for both circuits. PWM doesn't know if it is high side switched or low side switched.
Wired in the switch position so that the current goes through it the right direction it seems to me like it would work.
If it doesn't/can't work, could someone that understands draw me a simple picture so I can understand, please?
[Updated on: Wed, 17 August 2016 17:27] Report message to a moderator |
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