Dc Snubber Calculator Series Connected Capacitor

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The maximum energy dissipated in the resistor is no more than the energy stored in the inductor.

Since this is typically small, the resistor dissipation will also be small.

If you want to get technical you would need to know the surge energy (or peak transient power) that the resistor can tolerate.

Your main mistake seems to be in failing to understand or consider the transient nature of the response of this circuit.

Present your calculations in a more logical sequence and it might be possible to offer you some guidance.

Likely a 1 watt resistor could handle that if it didnt have to do it very often.

As they indicated in the first post this is their uncertainty.

With 220V 50 Hz the notional steady state zero offset current in a 0.55H solenoid would be 1.3A RMS or 1.8A peak.

In any event the energy would be at most 1.8 Joules were the switch opened at the highest energy condition.

Hi Eng TnK I can understand from your reply that: 1- when the switch is closed the current is AC, and all rules will be on AC current.

DC,and all rules will be on DC current.

The AC analysis will tell you the circuit conditions from the time when the switch is closed until the switch is opened.

Once the switch is opened you take the initials conditions to be.

Inductor Current Capacitor Voltage You then perform a transient analysis to determine what happens as the stored energy in the RLC loop is dissipated in the snubber resistor.

The chief concern of the design process would be to protect the switch from excessive over-voltage.

Using your given circuit parameters the peak switch voltage could potentially exceed 850V.

Strictly speaking both the AC and DC analyses might need to be a transient solution since there is no indication from you as to the time frame in which the switch is closed and then opened.

One would need to know the particular application you have in mind.

It may well be that the switching device is semiconductor in type and in addition to the over-voltage stress issue one would have to ensure the snubber design allowed for the device peak current ratings.

Very few of them appear to realise that you are using a 50Hz AC source and therefore the switch operation is likely to be maybe a few times a day or at most 50Hz if the switch is actually a thyristor.

Im guessing it is not operating at 50Hz and therefore you do not need to consider the energy in the coil in quite the way you have.

Dc Snubber Calculator Series Connected Capacitor

Your main concern should be the continuous power in the resistor because of the series connected capacitor.

You seem to be ok with the mathematics so Ill assume you can make those calculations.