The working fluid is delivered to the system through flow-control valve 6 to nozzle 3. When the temperature of the item being regulated increases, thermal bulb 1 disiplaces shutter 2 with respect to nozzle 3 to the right, increasing the pressure on membrane 5. This lowers rod 4, rigidly attached to the membrane, reducing the supply of heat-carrying agent to the system an thereby reducing the temperature of the item being regulated. As rod 4 moves downward, it turns lever 13, compressing bellows 7 and 8, and stretching bellows 9 and 10. The last two bellows compress spring 11. At this, lever 14 is turned about fixed axis A, closing flow-control valve 6 to some extent with a needle member and reducing the delivery of the working fluid to the system. This reduces the pressure on membrane 5. Then, as the fluid in the upper bellows flows back to the lower bellows through flow-control valve 12, the bellows return to their middle position as does flow-control valve 6.
$4102$EHP,Rg$