commgrp@silver.UUCP (02/27/87)
During World War II, the Soviet Union manufactured a thermoelectric generator which was used to charge lead-acid batteries for radios. It replaced the chimney of a kerosene lamp, and looked like a radial array of fins. There was a sketch of one in an old (circa 1960) POPULAR ELECTRONICS article about radio jamming. Does anyone know details of this device? One might surmise that it was an array of high-current thermocouples, probably made of inexpensive materials, e.g., iron and copper, but it must have produced at least 2.2 volts. A device called the "Compact Silent Generator" now being marketed in the US generates 5 watts at 12 v., probably contains Peltier semiconductor refrigeration units operating in reverse. It's a nice gadget but $119 is too much! Frank Reid PO Box 5283 Bloomington IN 47402 reid@gold.bacs.indiana.edu
larry@kitty.UUCP (03/04/87)
In article <24300001@silver>, commgrp@silver.bacs.indiana.edu writes: > During World War II, the Soviet Union manufactured a thermoelectric > generator which was used to charge lead-acid batteries for radios. It > replaced the chimney of a kerosene lamp, and looked like a radial array > of fins. > > Does anyone know details of this device? One might surmise that it was > an array of high-current thermocouples, probably made of inexpensive > materials, e.g., iron and copper, but it must have produced at least 2.2 > volts. I don't know anything about the above Russian device, but I can comment about a "thermal battery" which was developed during World War II for use as a power source for electronic proximity fuses used in artillery shells and rockets. This thermal battery was developed by the Wurlitzer Company (of piano, organ and jukebox fame). Wurlitzer turned their resources from manufacturing consumer goods to military materiel during the war, as did many other companies. This thermal battery consisted of two thermopiles (i.e., an array of thermocouple junctions in series-parallel): one for low-voltage, high-current for filament power, and the other for high-voltage, low-current for plate B+ power. The thermopiles were powered by the hot exhaust gases and burning propellant of mortar shells, anti-submarine rockets, etc. The thermal battery is an interesting device since it must be capable of several years shelf-life, but yet be ready for instant use with a high degree of reliability. The actual operational life of the battery is usually measured in seconds. Thermal batteries are still used in the above and other military applications, but they are no longer made by Wurlitzer - who got out of that military business during the 50's. Thermal batteries generally use a a semiconductor as one or both of the thermocouple elements (after all, we want power, not temperature -> voltage linearity here :-) ). I don't recall what Wurlitzer used during World War II, but contemporary thermal batteries use such materials as lead telluride, germanium-silicon alloy, and a silver-antimony-tellurium alloy. Thermal batteries are not known for efficiency; it is generally less than 5%. Another type of battery used in artillery applications (where the shell is propelled from a gun with an external explosive) is a primary cell whose electrolyte is sealed in a frangible container which ruptures upon acceleration. I have always been somewhat bemused by the design philosphies behind the above batteries: here's a battery which must be reliable, have a shelf life of many years, have an operational life measured in seconds, and yet the battery can never be "tested" prior to use! > A device called the "Compact Silent Generator" now being marketed in the > US generates 5 watts at 12 v., probably contains Peltier semiconductor > refrigeration units operating in reverse. It's a nice gadget but $119 > is too much! I have seen thermoelectric generators manufactured by Westinghouse that put out 50 watts and use propane, butane or natural gas fuel with an input energy around 15,000 BTU/hr. A flame heats a junction array to a temperature around 250 deg C. The 50-watt size is not very large: about 1 foot in diameter and 3 feet high, including "chimney". These generators are handy for telemetering and control purposes on gas pipelines where commercial electric power is not available. The operational philosophy is to have the thermal battery trickle charge ni-cads, which contain the reserve energy needed to operate motor-driven valves, and for use during a thermal generator "flameout". <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rocksanne|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|seismo|utzoo}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
sgcpal@watdcsu.UUCP (03/06/87)
In article <24300001@silver> commgrp@silver.bacs.indiana.edu writes: >During World War II, the Soviet Union manufactured a thermoelectric >generator which was used to charge lead-acid batteries for radios. It >replaced the chimney of a kerosene lamp, and looked like a radial array >of fins. > >Does anyone know details of this device? One might surmise that it was >an array of high-current thermocouples, probably made of inexpensive >materials, e.g., iron and copper, but it must have produced at least 2.2 >volts. I was sure that I had seen such a device before. > After consulting my undergrad text on the subject I found a picture of such a device which was (maybe still) manufactured by 3M. It produced 200mW at 9V. It could run for 24 hrs on a tank of fuel (kerosene) that looks like the one on a standard coleman lattern. It goes on to say that the thermocouples(I count 6) were hermentically sealed. Therefore expensive? It is described in: B.Swanson and E. Somers, "Optimization of a Conventional-Fuel-Fired Thermoelectric Generator," Journal of Heat Transfer, 81(1959), pp. 245-248. A. Bayne Neild, "Portable Thermoelectric Generators," Paper No 645A, Transactions of the SAE(1963). The text in which I found the info was: S. Angrist, "Direct Energy Conversion," 3rd edition, Allyn and Bacon Inc., Boston(1976), pp. 176. Enjoy, Paul A. Layman University of Waterloo, Electrical Engineering, Silicon Devices and Integrated Circuits Research Group (SiDIC) UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!watdcsu!sgcpal
ornitz@kodak.UUCP (barry ornitz) (03/09/87)
In article <3086@watdcsu.UUCP> sgcpal@watdcsu.UUCP (P.A.ul Layman [EE-Device Physics]) writes: >After consulting my undergrad text on the subject I found a picture of >such a device which was (maybe still) manufactured by 3M. It produced >200mW at 9V. It could run for 24 hrs on a tank of fuel (kerosene) that looks >like the one on a standard coleman lattern. It goes on to say that the >thermocouples(I count 6) were hermentically sealed. Therefore expensive? I know of no ordinary thermocouple junctions that put out 1.5 volts with the temperature differential available as described. With a 1000 degree F differential, iron-constantan thermocouples put out about 30 mV. [I know that thermocouples do not actually respond to temperature differentials, but rather to temperature gradients.] Probably what are shown are thermopiles which are composed of many thermocouples in series. If you want to build your own, you need to place many, many thermocouples in series. Note that the tabulated voltages for thermocouple pairs are actually open-circuit voltages; if current is drawn from the thermocouple, the hot end will be cooled and the cool end will be heated. A good source for the wire, if you are interested, is: Omega Engineering, Inc., One Omega Drive, Box 4047, Stamford, CT 06907. Barry L. Ornitz