RODALCO
Well-Known Member
Hero999
It still protects the LED.
The 1 N4007 is a 1 kV diode, the LED is in series with it, and can only handle 6 Volts reversed max. so a nasty spike while the LED is not conducting and revere biased still could kill the LED, for the sake of a 5 cts diode and 20 seconds extra soldering time a extremely reliable potential indicator for 230 Volts is built.
I know the two series resistors will limit the available voltage across the LED anyway, but better reliable than popped LED and repair.
If reversed voltage sharing with two diodes is required both diodes have to have same voltage and current rating ideally, IMO.
In the 1500 or so meters I have installed 3 LED's each in makes 4500 * 230 Volts LED's with NO faillures. Try to beat that. !!
It still protects the LED.
The 1 N4007 is a 1 kV diode, the LED is in series with it, and can only handle 6 Volts reversed max. so a nasty spike while the LED is not conducting and revere biased still could kill the LED, for the sake of a 5 cts diode and 20 seconds extra soldering time a extremely reliable potential indicator for 230 Volts is built.
I know the two series resistors will limit the available voltage across the LED anyway, but better reliable than popped LED and repair.
If reversed voltage sharing with two diodes is required both diodes have to have same voltage and current rating ideally, IMO.
In the 1500 or so meters I have installed 3 LED's each in makes 4500 * 230 Volts LED's with NO faillures. Try to beat that. !!