A New Level of Sophistication: Direct Conversion
A revolution is in the making. We know now that we can force the heat-and-electricity-carrying electrons residing in matter to do our bidding without the use of shafts and pistons. This is a leading accomplishment of modern technology: energy transformation without moving parts. It is called direct conversion.
The thermoelements shown above the turbogenerator in [Figure 1] illustrate the contrast between direct and dynamic conversion. The thermoelements convert heat into electricity directly, without any of the intervening machinery seen in the turbogenerator.
Figure 1 Direct conversion devices, such as the spokelike lead telluride thermoelectric elements inside the SNAP 3 radioisotope generator shown above (courtesy Martin Company), convert heat into electricity without moving parts. In contrast, the SNAP 2 dynamic converter shown below SNAP 3 (courtesy Thompson Ramo Wooldridge, Inc.) includes a high-speed turbine, an electric generator, and pumps to produce electricity from heat. (NaK is a liquid mixture of sodium and potassium.)
DIRECT VERSUS DYNAMIC CONVERSION SNAP 3 LESS THAN 5 WATTS 5″ SNAP 2 3000 WATTS 24″ ALTERNATOR ROTOR ALTERNATOR STATOR TURBINE ROTORS NaK PUMP DIFFUSER NaK PUMP ROTOR MERCURY JET BOOSTER PUMP MERCURY CENTRIFUGAL PUMP MERCURY THRUST BEARING MERCURY BEARING MERCURY BEARING