Toy Tricks and Mind Tricks : Jacob Rabinow

On a long car trip, Rabinow’s patent attorney presented a challenge. Could the engineer invent an inexpensive, easy-to-make device for the attorney’s desktop to indicate if a telephone call had been received by his answering service. As they drove along, Rabinow suddenly recalled a faded memory stemming from his days as an 11-year-old boy working in his uncle’s New York City toy and candy store. One of the toys that piqued his interest was a small cardboard box shaped like a doghouse containing a celluloid bulldog. The dog jumped out of the box when it was loudly called for or clapped for. At the back of the doghouse were two electrical contacts, with a loosely hanging piece of brass resting against them. The brass closed the circuit that ran from the battery to an electromagnet. The magnet held a piece of flat steel attached to a spring called an armature. When a loud sound vibrated the box, the brass piece was shaken from the contacts for a short time. The circuit opened briefly, and the magnet released the armature. The dog would then be propelled out of the house, disconnecting the circuit.

This became the principle for Rabinow’s Telephone Call Indicator. The Indicator used a loose contact that broke when the phone rang, opening a shunt to resistor and causing the voltage to jump to a high value. When the voltage jumped, a neon light lit. Because of a unique property of neon, the light stayed lit even after the sound ceased, the circuit closed, and the voltage dropped.

Rabinow hadn’t thought about the dog toy until that car ride 33 year later. When he recounted this story, Rabinow said he was doubtful that he had stored the memory in any “mental cubbyhole” that would have made it retrievable later on. Rather, the inventor said he thought his mind had mysteriously offered up a useful bit of information at the right moment much like a poet’s muse offers up the inspiration for verse.

Objects :
Telephone Call Indicator