The DeLorean then travels back to 1955 to restore the timeline, and Doc later states in a letter to Marty that the bolt caused a " gigawatt overload " which " shorted out the time circuits and destroyed the flying circuits ".
32.
The tetrodes were switched on and off by a pair of mercury vapour thyratrons connected to a timing circuit, the output of which biased the control and screen grids of the tetrode positively while a bias signal kept it normally turned off.
33.
The only time circuit breakers were invoked was on Oct . 27, when the market closed for 30 minutes at 2 : 35 p . m ., and then closed for the day at 3 : 30 p . m . when the 550-point level was reached.
34.
These capacitors have a low dissipation factor and because of their relatively temperature-independent electrical properties of about ?0 ppm over the entire temperature range, they had many applications for low-loss and temperature-stable applications such as timing circuits, precision analog circuits, and signal filters in applications with tough environmental conditions.
35.
The DeLorean then disappears from 1955, travelling back in time to January 1, 1885 ( earlier in the film, Doc mentions that the time circuits are not functioning correctly; several instances in the film that show the time circuit display showed 1885 as the destination when the time circuits malfunctioned ).
36.
The DeLorean then disappears from 1955, travelling back in time to January 1, 1885 ( earlier in the film, Doc mentions that the time circuits are not functioning correctly; several instances in the film that show the time circuit display showed 1885 as the destination when the time circuits malfunctioned ).
37.
The DeLorean then disappears from 1955, travelling back in time to January 1, 1885 ( earlier in the film, Doc mentions that the time circuits are not functioning correctly; several instances in the film that show the time circuit display showed 1885 as the destination when the time circuits malfunctioned ).
38.
Gruberman manages to escape, and in an ensuing chase with Sludge, he drives the RV off the Mount Rushmore national monument, and when telling God that he will soon be with him, the vehicle reaches 88 miles per hour, sending him back to the date of his first mission 1 week prior ( as Will Powers had put the date into the time circuits to mark the event ).
