Wiggy Solenoid Voltmeter was Precursor to Multimeter and Non-Contact Voltage Tester
When it comes to measuring and testing voltage, most electricians these days use digital multimeters, which can be used to measure multiple electrical properties, and non-contact voltage testers that can safely check for electrical current without making contact. Before the 1990s, however, the tool of choice for electricians for more than 70 years was the solenoid voltmeter, commonly known as the Wiggy.
The solenoid voltmeter was invented by George Wigginton and patented by the Wigginton Company in 1918. Originally dubbed Wiggins, it became known as the Wiggy when Square D came out with their version. From there, it took off in popularity and practically every electrician carried a Wiggy in one back pocket and a screwdriver and a pair of lineman pliers in the other. Electricians seldom let it out of their sight, and on the rare occasions they let someone borrow their Wiggy, they made sure to get it back.
The Wiggy uses a solenoid coil to attract a spring-loaded plunger. As voltage increases, magnetism pulls the solenoid’s core in further against the spring, thereby moving a pointer indicating the voltage reading. DC polarity is indicated by loud clicking, and when connected to AC the Wiggy vibrates and emits a buzzing sound. The Wiggy is quite rugged and can be subjected to rough handling without affecting its functionality, unlike today’s digital multimeters which must be handled much more delicately. In the 1980s, Ideal Industries’ bright yellow solenoid voltmeter became popular among electricians until eventually Wiggy’s prevalence was usurped by non-contact pen-style testers due to their compact size and ease of use.
Many of today’s young electricians are unfamiliar with the solenoid voltmeter because there are certainly better options available. But the older generation looks back with fondness on the Wiggy voltmeters that served them well for most of their careers.