Read Research logo
 
Home Projects Utilities Articles Links Contacts

Soft Start

Introduction

 This is a really simple, but effective solution to big inrush currents on start-up. It is fail-safe as it uses an NTC to limit the current so if the relay fails no damage to either the switched appliance nor the soft start itself should occur. It also resets quickly so should provide protection again even straightaway after the appliance has been turned off. The delay before the relay closes is about 0.5 seconds.

 

Downloads

 Schematic PDF of schematic

PCB Copper PDF of copper side of PCB

PCB Component PDF of component side of PCB

 

 All content on this website Copyright © 2005-2008 Richard Read, unless otherwise stated. For commercial use please contact me.