{"id":5136,"date":"2021-08-31T11:24:35","date_gmt":"2021-08-31T05:54:35","guid":{"rendered":"https:\/\/www.goseeko.com\/blog\/?p=5136"},"modified":"2025-12-08T09:41:47","modified_gmt":"2025-12-08T04:11:47","slug":"what-is-a-snubber-circuit","status":"publish","type":"post","link":"https:\/\/www.goseeko.com\/blog\/what-is-a-snubber-circuit\/","title":{"rendered":"What is a Snubber Circuit?"},"content":{"rendered":"\n

Snubber Circuit is the one used for suppressing voltage spikes. These are energy absorbing circuits. Normally, the voltage spike occurs due to the inductor<\/a> present in the circuit. Most basic form of snubber circuit is the RC snubber circuit. Below shows the figure of the snubber circuit having resistor and capacitor in series.<\/p>\n\n\n\n

<\/p>\n\n\n\n

Designing <\/strong><\/h2>\n\n\n\n

We take our first assumption as the circuit is having negligible impedance. The value of peak current in the circuit will be calculated using the relation<\/p>\n\n\n\n

<\/p>\n\n\n\n

Where:<\/p>\n\n\n\n

Vo<\/sub>= It is the value of Open circuit voltage<\/p>\n\n\n\n

Rs<\/sub> =It is the value of Snubber Resistance<\/p>\n\n\n\n

The rate of change of voltage w.r.t time is calculated as<\/p>\n\n\n\n

<\/p>\n\n\n\n

From above two equations we can write<\/p>\n\n\n\n

<\/p>\n\n\n\n

According to Ohm\u2019s Law<\/p>\n\n\n\n

R=Vo<\/sub>\/I<\/p>\n\n\n\n

I = switching current <\/p>\n\n\n\n

Vo<\/sub>= open circuit voltage  <\/p>\n\n\n\n

The energy dissipated in the snubber circuit will be equal to the energy dissipated by the capacitor. Because of this the value of the capacitor is selected such that the resistor will dissipate half of the wattage rating of the resistor.<\/p>\n\n\n\n

<\/p>\n\n\n\n

Where:<\/p>\n\n\n\n

f= Value of switching frequency<\/p>\n\n\n\n

2f= Transitions\/ cycle<\/p>\n\n\n\n

Condition for snubber circuit<\/strong><\/h2>\n\n\n\n

Firstly, the energy stored in the circuit capacitor should be greater than the energy stored in the circuit inductance.<\/p>\n\n\n\n

<\/p>\n\n\n\n

Where:<\/p>\n\n\n\n

Vo<\/sub>= open circuit voltage  <\/p>\n\n\n\n

I = Value of closed circuit current<\/p>\n\n\n\n

L= Inductance<\/p>\n\n\n\n

Secondly, for this circuit the time constant should be less than 10% of the ON time.<\/p>\n\n\n\n

<\/p>\n\n\n\n

Where:<\/p>\n\n\n\n

TON<\/sub>= shortest on-time expected <\/p>\n\n\n\n

R = snubber resistance <\/p>\n\n\n\n

C = snubber capacitance <\/p>\n\n\n\n

Interested in learning about similar topics? Here are a few hand-picked blogs for you!<\/strong><\/p>\n\n\n\n