12 volts led power input indicator circuit

[mixos1]

This simple circiut setup, is what i use to indicate 12 volts dc into all my circiuts, even the high voltage circiuts. and for 24 volts input change the resistor to 1.2k . faceing the rear of the togle switch the togle at the front is switched upwards, when wireing up this ,to indicate 12 volts dc to be flowing into your circiut.

by Steven

 

[hotwaterwizard2]

Here is a 120 volt unit

View attachment 35322

 

[steven2]

: thanks john its great to see circuits like that,steven

 

[Kevin Weddle]

Let's talk specifics. The 120vac will indicate the LED as well as other voltages. We should try to indicate only that which is there.

 

[audioguru2]

Hotwaterwizard,
If the capacitor is discharged, and you apply power at the time that the AC voltage is at its peak of 170V, the LED must pass 1.7A for a moment. If you turn-off the power when the AC voltage is at its peak of one polarity, then while the capacitor is charged, apply the power when the AC voltage is at the other polarity, 3.4A!
Can an LED withstand such abuse?
Doesn't the LED flicker?

Kevin,
The 12V and 24V circuits also indicate on many other voltages. The resistor limits the current, not voltage.