Erjon Ameti Posted August 18, 2020 Report Share Posted August 18, 2020 Hello We designed this Snubber Circuit with this varistor in parallel but we have a problem in a small load. Even when the relay is disconnected, a small current is flowing. For example, when connecting a phone charger, the phone screen keeps turning on and off. The varistor is Hongzhi Elec 7D471K The resistor is 2.2 ±5% 1W ±350ppm/°C Axial,3.3x9.2mm Carbon The capacitor is 100nF ±10% 275VAC 10 Through Hole,P=10mm Suppression Capacitors I think the problem is with the capacitor and maybe I need a smaller one to increase the impedance and limit the current flow or schematic problem. Quote Link to comment Share on other sites More sharing options...
HarryA Posted August 18, 2020 Report Share Posted August 18, 2020 The capacitance reactance of the 100nf would be in the order of 26.6K so that could give you a current in the order of a few milli-amperes. The leakage current of the varistor is less than 20 micro-amperes for the 7D471K. Quote Link to comment Share on other sites More sharing options...
Erjon Ameti Posted August 19, 2020 Author Report Share Posted August 19, 2020 Hey guys, Thanks for your replies. We tried to connect the snubber in the load and till now everything seems to be okay. This also solved our resetting problem of ESP8266 in our PCB. Quote Link to comment Share on other sites More sharing options...
Erjon Ameti Posted August 19, 2020 Author Report Share Posted August 19, 2020 Here are some simulations for the snubber in relay contact and in load. The effect of the snubber is okay in both cases but in the load there is no current leak. Quote Link to comment Share on other sites More sharing options...
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