It is possible to connect the dogs together with lever mechanisms so that they are all activated simultaneously via a single wheel or lever, but this adds complexity which increases the cost of the door and its required maintenance.
22.
The lever is then moved back, allowing the contacts to close and grip the pins of the IC . ZIF sockets are much more expensive than standard IC sockets and also tend to take up a larger board area due to the space taken up by the lever mechanism.
23.
The mechanics of drag systems usually consist of any number of discs ( drag washers ) arranged in a stack on the spool shaft or in some cases, on the drive shaft . There is generally a screw or lever mechanism that presses against the washers the higher the pressure, the greater the resistance.
