That reminds me: If you're interested in this older stuff, keep a look out for the "Basic Electricity" and "Basic Electronics" series of books which were published by Van Valkenburgh, Nooger & Neville Inc. in the 1950s/60s.
They were written originally as instructional materials for the U.S. forces, and include operational descriptions of vibrators and dynamotors, as well as many other topics. There were editions re-written into "British Commonwealth" English and terminology as well, which may well have found their way to Australia and New Zealand. Public libraries might be able to get hold of them. Well worth a read.
