RODALCO
Well-Known Member
I did read in one of the older posts a request for a simple circuit for a 230 Volts LED.
Well here it is:
(background info)
Here in the local powerboard this circuit has been used for about 15 years with no problems for potential indicators in CT meters.
With the new high efficiency LED's only about 3 mA is required for a good light output hence not much energy is wasted in the series resistor.
The last 5 years we use 2 * 33 or 39 k Ohm 1 Watt resistors in series and a 1N4007 diode to get the running current to around 2 to 3 mA.
A 1N914 or 1N4448 is used in antiparallel with the LED.
Previously we used 47 k Ohm 4 Watt resistor in series with the older type of LED's.
Capacitors of 22 and 47 nF 1 kV were tried too, but spikes on the mains sometimes caused the LED's to fail. For reliability on utility meters to check for blown PT fuses the resistive method was preferred.
**broken link removed**
Blue LED with 2 * 39 k Ohms , Red LED with 2 * 33 k Ohms.
These are standard 5000 milli candela LED's.
**broken link removed**
Blue and Red LED from different angle.
Of course all mains exposed wires require proper insulation heatshrinks fitted around the exposed wiring ends for safety.
Well here it is:
(background info)
Here in the local powerboard this circuit has been used for about 15 years with no problems for potential indicators in CT meters.
With the new high efficiency LED's only about 3 mA is required for a good light output hence not much energy is wasted in the series resistor.
The last 5 years we use 2 * 33 or 39 k Ohm 1 Watt resistors in series and a 1N4007 diode to get the running current to around 2 to 3 mA.
A 1N914 or 1N4448 is used in antiparallel with the LED.
Previously we used 47 k Ohm 4 Watt resistor in series with the older type of LED's.
Capacitors of 22 and 47 nF 1 kV were tried too, but spikes on the mains sometimes caused the LED's to fail. For reliability on utility meters to check for blown PT fuses the resistive method was preferred.
**broken link removed**
Blue LED with 2 * 39 k Ohms , Red LED with 2 * 33 k Ohms.
These are standard 5000 milli candela LED's.
**broken link removed**
Blue and Red LED from different angle.
Of course all mains exposed wires require proper insulation heatshrinks fitted around the exposed wiring ends for safety.