I'm looking for a way to check if some devices have power.
There are solutions like cheap 5V wall warts, relays, neon glow lamp...
But from my point of view the power waste is to big.
Also relays have the problem that most of them are not build for high and low voltage switching.
It would be easy to use a double switching relay if not both switches would be AgSnO2.
Ok, sorry if the german guy on the other end used the wrong word
For me Power = On - like it is printed on all the on switches
If you look at it from the physics side then you are right.
There are solutions like cheap 5V wall warts, relays, neon glow lamp...
But from my point of view the power waste is to big.
You can detect voltage with very low power consumption, but you still need some power to drive your circuit and/or to drive an LED. For example, a digital multimeter might have in input impedance of 10-100 megohms, but it's powered by a battery.
How much power does one of those little neon lamps require? It can't very significant.
The neon lamps use ~0,35W.
From my point of view thats allot. In times where we change to LEDs in our house (incandescent light bulbs are already
banned here in Europe) and with the electricity price....
10 of this neon lamps running 24x365 is near $10 a year.
So if you look at all the stuff around the house, every watt counts.
I imagine that the 58 mW rating is the maximum power dissipation.
I can light up those neon bulbs with static electricity from a hair comb, so a few microwatts ought to suffice for enough light to indicate that voltage (greater than about 90 V) is applied.
0.6mA at 90V is about 58mW, so I think that is the rated power under normal use. Bright enough to see in a panel indicator, with a sensitive detector you could certainly reduce the drive.
As you can see in the datasheet from my dimmers they can do everything (leading phase angle / trailing phase angle).
I use electronic transformers for my LEDs.
The datasheet says:
Mixing of L loads (inductive loads, e.g. wound transformers) and C loads (capacitive loads,
e.g. electronic transformers) is not permitted. R loads (ohmic loads, e.g. 230V incandescent
lamps and halogen lamps) may be added anytime.
Hm, sounds save to put the neon lamp in parallel to the transformer.
Also from the datasheet:
Glow lamp current up to 5mA starting at 110V
I really don't want to kill such a expensive dimmer and need to be sure it will work.
polymorph:
0.6mA at 90V is about 58mW, so I think that is the rated power under normal use. Bright enough to see in a panel indicator, with a sensitive detector you could certainly reduce the drive.
The neons on the back of camera flashes run at about 40 uA and are still bright enough to see.
I have now the idea to be able to also set the brightness of my lamps via the Arduino.
If i use the neon lamps behind the dimmer and they also get dimmed it should be
possible with some logic in the code.
The question is what would work best: LDR, Photodiode or Phototransistor?
Then i have now another problem.
I need this self made optocoupler one time on some cable that is ~10 meter but just on and off (no dimmer) and it doesn't need
to be fast. It's J-Y(St)Y cable (~ AWG 23) and i think 5V over 10 meter and an LDR is not a good idea.
But i also have 24VDC there...
LDR + 24V + voltage divider possible or what can i do?
You should have written this all down on paper and sent it in to the people that run this site. Have you any idea how many LEDs have been twinkled by your packets being routed around the internet to get this subject posted?
No wonder we're all suffering such financial hardships!