Creating new topic as the Q is different.
I have a need to display ON condition of 19 mains signals (heating system)
Zone valves, Boiler, pump etc.
I can get the 220V 'ON' for each part easily enough .... want a simple way to have an LED indicate state ... illuminated = ON
After a lot of Googling around found
http://www.marcspages.co.uk/tech/6103.htm
in particular the cct:
However this cct seems to be flawed.
The in-rush current is ~1.5A and blows the LED's
The LED current should be limited to 20mA
I have purchasde the diode bridges, LED & Capacitors.
W10 Bridge recifiers
LED are standard 5mm LED (100mcd) ... forward Voltage 1.8-2.2V
Capacitors are 0.47uF Polypropylene X2 series rated for 240V AC use
The purpose of series resistor is to limit the inrush current (and suppress harmonics)if the circuit is energised when mains voltage is at peak, the capacitor will
momentarily behave like a short circuit. The 220ohm will result in 1.5A through the LED - built a test cct and they are failing.
Could someone knowledgeable take a look and see how I can make this work .... no resistors bought yet .... but having bought the LED, Rectifiers & capacitors keen to use those.
I wanted to use the capacitor voltage drop approach to avoid using a resistor as voltage dropper, as heat dissipated is too high for 19 of them.