white_micro
New Member
Hello,
The coil attached has the following characteristics:
1. Winding: 3750 turns +/-10% of 40 awg double build polyurethane wire with Min. Of 130 °c temperature rating.
2. Resistance: 290 +/-10% ohms at 25 °c.
3. Force: must provide a min. Of 2.8N. At 0.059 striking distance at a supply voltage of 115 VDC.
In my application (protection relay) I have a three phase input voltage 120-600 VAC, and 12VDC for the control circuit. I was thinking of operating the coil directly from the AC line with a kind a solid state switch, but as I have three phase input, I could lose a phase unexpectedly, so I'd better actuate the coil from the DC rectified voltage which will be present even with two phases. The point is that the rectified voltage ranges from 170 to ~850VDC, so I can't let the high voltage across the coil for a long time, and I need the coil to trip in 30 ms. I think if the energy is removed quick enough, the shunt coil won't get damaged. I came up with the circuit attached. Do you think this could work or you have any recommendations?
The coil attached has the following characteristics:
1. Winding: 3750 turns +/-10% of 40 awg double build polyurethane wire with Min. Of 130 °c temperature rating.
2. Resistance: 290 +/-10% ohms at 25 °c.
3. Force: must provide a min. Of 2.8N. At 0.059 striking distance at a supply voltage of 115 VDC.
In my application (protection relay) I have a three phase input voltage 120-600 VAC, and 12VDC for the control circuit. I was thinking of operating the coil directly from the AC line with a kind a solid state switch, but as I have three phase input, I could lose a phase unexpectedly, so I'd better actuate the coil from the DC rectified voltage which will be present even with two phases. The point is that the rectified voltage ranges from 170 to ~850VDC, so I can't let the high voltage across the coil for a long time, and I need the coil to trip in 30 ms. I think if the energy is removed quick enough, the shunt coil won't get damaged. I came up with the circuit attached. Do you think this could work or you have any recommendations?
