Printed wiring circuit guard ring

A printed wiring circuit board intended for automotive speed control circuit applications;

• said circuit including a low leakage memory capacitor connected to provide a speed reference function;
• a first electrical relay connected to establish a controlled charge on said capacitor;
• a controlled accelerate component group including a large value resistor, a second electrical relay, and a capacitor having a value large compared with said memory capacitor;
• said group connected to provide for a slowly changing increment of charge on said memory capacitor in response to the controlled actuation of said relays, and having a common point of connection on said printed wiring board;
• said circuit board comprising:
• an insulating substrate having metallic conductors arrayed thereon to establish the wiring pattern necessary to interconnect the components of said circuit, and a conductive ring immediately surrounding said common point of connection, said ring being connected to a source of potential approximating the normal operating potential of said common point.