Snubber Circuit Design 230V, 16A, Problem in small load, Current Flow!

Thread Starter


Joined Aug 18, 2020
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.


Joined Sep 17, 2013
Welcome to AAC!
With 230V 50Hz mains and a low impedance load you get about 7mA per 100nF of capacitance. A smaller cap will indeed reduce the current but also reduce the snubber effectiveness.


Joined Aug 7, 2020
What is the load?
If it is just a resistor then you don't need a snubber.

If the load is inductive, you can neutralise it by putting a snubber across the load with R = series resistance of inductor and C = L/R^2